diff --git a/src/ui/public/fancy_forms/fancy_forms.js b/src/ui/public/fancy_forms/fancy_forms.js
index 1dd23015894dc..457b1aa01442d 100644
--- a/src/ui/public/fancy_forms/fancy_forms.js
+++ b/src/ui/public/fancy_forms/fancy_forms.js
@@ -12,16 +12,16 @@ uiModules
       // directive providers are arrays
       $delegate.forEach(function (directive) {
         // get metadata about all init fns
-        var chain = [directive.controller, DecorativeController].map(function (fn) {
-          var deps = $injector.annotate(fn);
+        let chain = [directive.controller, DecorativeController].map(function (fn) {
+          let deps = $injector.annotate(fn);
           return { deps: deps, fn: _.isArray(fn) ? _.last(fn) : fn };
         });
 
         // replace the controller with one that will setup the actual controller
         directive.controller = function stub() {
-          var allDeps = _.toArray(arguments);
+          let allDeps = _.toArray(arguments);
           return chain.reduce(function (controller, link, i) {
-            var deps = allDeps.splice(0, link.deps.length);
+            let deps = allDeps.splice(0, link.deps.length);
             return link.fn.apply(controller, deps) || controller;
           }, this);
         };
diff --git a/src/ui/public/fancy_forms/kbn_form_controller.js b/src/ui/public/fancy_forms/kbn_form_controller.js
index 2fbdbab4ca47e..c4b9f4ef19717 100644
--- a/src/ui/public/fancy_forms/kbn_form_controller.js
+++ b/src/ui/public/fancy_forms/kbn_form_controller.js
@@ -7,7 +7,7 @@ import _ from 'lodash';
  * @param {$scope} $scope
  */
 function KbnFormController($scope, $element) {
-  var self = this;
+  let self = this;
 
   self.errorCount = function (predicate) {
     return self.$$invalidModels().length;
@@ -21,14 +21,14 @@ function KbnFormController($scope, $element) {
   };
 
   self.describeErrors = function () {
-    var count = self.softErrorCount();
+    let count = self.softErrorCount();
     return count + ' Error' + (count === 1 ? '' : 's');
   };
 
   self.$$invalidModels = function (predicate) {
     predicate = _.callback(predicate);
 
-    var invalid = [];
+    let invalid = [];
 
     _.forOwn(self.$error, function collect(models) {
       if (!models) return;
@@ -40,7 +40,7 @@ function KbnFormController($scope, $element) {
         } else {
           if (predicate(model)) {
             // prevent dups
-            var len = invalid.length;
+            let len = invalid.length;
             while (len--) if (invalid[len] === model) return;
 
             invalid.push(model);
diff --git a/src/ui/public/field_editor/field_editor.js b/src/ui/public/field_editor/field_editor.js
index ef4f8c6c0cb81..3b4692eb1120a 100644
--- a/src/ui/public/field_editor/field_editor.js
+++ b/src/ui/public/field_editor/field_editor.js
@@ -11,10 +11,10 @@ import fieldEditorTemplate from 'ui/field_editor/field_editor.html';
 uiModules
 .get('kibana', ['colorpicker.module'])
 .directive('fieldEditor', function (Private, $sce) {
-  var fieldFormats = Private(RegistryFieldFormatsProvider);
-  var Field = Private(IndexPatternsFieldProvider);
-  var scriptingInfo = $sce.trustAsHtml(require('ui/field_editor/scripting_info.html'));
-  var scriptingWarning = $sce.trustAsHtml(require('ui/field_editor/scripting_warning.html'));
+  let fieldFormats = Private(RegistryFieldFormatsProvider);
+  let Field = Private(IndexPatternsFieldProvider);
+  let scriptingInfo = $sce.trustAsHtml(require('ui/field_editor/scripting_info.html'));
+  let scriptingWarning = $sce.trustAsHtml(require('ui/field_editor/scripting_warning.html'));
 
   return {
     restrict: 'E',
@@ -25,8 +25,8 @@ uiModules
     },
     controllerAs: 'editor',
     controller: function ($scope, Notifier, kbnUrl) {
-      var self = this;
-      var notify = new Notifier({ location: 'Field Editor' });
+      let self = this;
+      let notify = new Notifier({ location: 'Field Editor' });
 
       self.scriptingInfo = scriptingInfo;
       self.scriptingWarning = scriptingWarning;
@@ -43,9 +43,9 @@ uiModules
 
       self.cancel = redirectAway;
       self.save = function () {
-        var indexPattern = self.indexPattern;
-        var fields = indexPattern.fields;
-        var field = self.field.toActualField();
+        let indexPattern = self.indexPattern;
+        let fields = indexPattern.fields;
+        let field = self.field.toActualField();
 
         fields.remove({ name: field.name });
         fields.push(field);
@@ -64,8 +64,8 @@ uiModules
       };
 
       self.delete = function () {
-        var indexPattern = self.indexPattern;
-        var field = self.field;
+        let indexPattern = self.indexPattern;
+        let field = self.field;
 
         indexPattern.fields.remove({ name: field.name });
         return indexPattern.save()
@@ -76,9 +76,9 @@ uiModules
       };
 
       $scope.$watch('editor.selectedFormatId', function (cur, prev) {
-        var format = self.field.format;
-        var changedFormat = cur !== prev;
-        var missingFormat = cur && (!format || format.type.id !== cur);
+        let format = self.field.format;
+        let changedFormat = cur !== prev;
+        let missingFormat = cur && (!format || format.type.id !== cur);
 
         if (!changedFormat || !missingFormat) return;
 
@@ -87,15 +87,15 @@ uiModules
       });
 
       $scope.$watch('editor.formatParams', function () {
-        var FieldFormat = getFieldFormatType();
+        let FieldFormat = getFieldFormatType();
         self.field.format = new FieldFormat(self.formatParams);
       }, true);
 
       // copy the defined properties of the field to a plain object
       // which is mutable, and capture the changed seperately.
       function shadowCopy(field) {
-        var changes = {};
-        var shadowProps = {
+        let changes = {};
+        let shadowProps = {
           toActualField: {
             // bring the shadow copy out of the shadows
             value: function toActualField() {
@@ -105,7 +105,7 @@ uiModules
         };
 
         Object.getOwnPropertyNames(field).forEach(function (prop) {
-          var desc = Object.getOwnPropertyDescriptor(field, prop);
+          let desc = Object.getOwnPropertyDescriptor(field, prop);
           shadowProps[prop] = {
             enumerable: desc.enumerable,
             get: function () {
@@ -130,7 +130,7 @@ uiModules
       }
 
       function initDefaultFormat() {
-        var def = Object.create(fieldFormats.getDefaultType(self.field.type));
+        let def = Object.create(fieldFormats.getDefaultType(self.field.type));
 
         // explicitly set to undefined to prevent inheritting the prototypes id
         def.id = undefined;
diff --git a/src/ui/public/field_format_editor/field_format_editor.js b/src/ui/public/field_format_editor/field_format_editor.js
index cea2b725122e3..ee60560543c21 100644
--- a/src/ui/public/field_format_editor/field_format_editor.js
+++ b/src/ui/public/field_format_editor/field_format_editor.js
@@ -13,7 +13,7 @@ uiModules
     },
     controllerAs: 'editor',
     controller: function ($scope) {
-      var self = this;
+      let self = this;
 
       // bind the scope values to the controller, down with $scope.values
       $scope.editor = this;
@@ -40,7 +40,7 @@ uiModules
        * @return {undefined}
        */
       $scope.$watch('editor.field.format.type', function (FieldFormat) {
-        var opts = FieldFormat && FieldFormat.editor;
+        let opts = FieldFormat && FieldFormat.editor;
 
         if (!opts) {
           delete self.$$pseudoDirective;
@@ -67,14 +67,14 @@ uiModules
 
     },
     link: function ($scope, $el) {
-      var scopesToTeardown = [];
+      let scopesToTeardown = [];
 
       function setupScope(opts) {
         if (typeof opts !== 'object') {
           return scopesToTeardown[scopesToTeardown.push($scope.$new()) - 1];
         }
 
-        var isolate = scopesToTeardown[scopesToTeardown.push($scope.$new(true)) - 1];
+        let isolate = scopesToTeardown[scopesToTeardown.push($scope.$new(true)) - 1];
         _.forOwn(opts, function (from, to) {
           isolate.$bind(to, from, $scope);
         });
@@ -88,21 +88,21 @@ uiModules
         if (!directive) return $el.hide();
         else $el.show();
 
-        var askedForChild = !!directive.scope;
-        var reuseScope = !askedForChild && !directive.controller;
+        let askedForChild = !!directive.scope;
+        let reuseScope = !askedForChild && !directive.controller;
 
-        var $formatEditor = $('<div>').html(directive.template);
-        var $formatEditorScope = reuseScope ? $scope : setupScope(directive.scope);
+        let $formatEditor = $('<div>').html(directive.template);
+        let $formatEditorScope = reuseScope ? $scope : setupScope(directive.scope);
 
         if (directive.controller) {
           // bind the controller to the injected element
-          var cntrlAs = (directive.controllerAs ? ' as ' + directive.controllerAs : '');
+          let cntrlAs = (directive.controllerAs ? ' as ' + directive.controllerAs : '');
           $formatEditorScope.Controller = directive.controller;
           $formatEditor.attr('ng-controller', 'Controller' + cntrlAs);
         }
 
-        var attrs = {};
-        var linkFns = directive.compile && directive.compile($el, attrs);
+        let attrs = {};
+        let linkFns = directive.compile && directive.compile($el, attrs);
         if (!linkFns || _.isFunction(linkFns)) {
           linkFns = {
             pre: _.noop,
diff --git a/src/ui/public/field_format_editor/pattern/pattern.js b/src/ui/public/field_format_editor/pattern/pattern.js
index 6ab0067653807..b13610f8c84f6 100644
--- a/src/ui/public/field_format_editor/pattern/pattern.js
+++ b/src/ui/public/field_format_editor/pattern/pattern.js
@@ -11,7 +11,7 @@ uiModules
     require: ['ngModel', '^fieldEditor'],
     scope: true,
     link: function ($scope, $el, attrs, cntrls) {
-      var ngModelCntrl = cntrls[0];
+      let ngModelCntrl = cntrls[0];
 
       $scope.$bind('inputs', attrs.inputs);
       $scope.$bind('placeholder', attrs.placeholder);
diff --git a/src/ui/public/field_format_editor/samples/samples.js b/src/ui/public/field_format_editor/samples/samples.js
index a752087b85b2e..d391af37d1556 100644
--- a/src/ui/public/field_format_editor/samples/samples.js
+++ b/src/ui/public/field_format_editor/samples/samples.js
@@ -11,7 +11,7 @@ uiModules
     require: ['?^ngModel', '^fieldEditor'],
     scope: true,
     link: function ($scope, $el, attrs, cntrls) {
-      var ngModelCntrl = cntrls[0];
+      let ngModelCntrl = cntrls[0];
 
       $scope.samples = null;
       $scope.$bind('inputs', attrs.inputs);
@@ -21,14 +21,14 @@ uiModules
         '[]inputs'
       ], function () {
         $scope.samples = null;
-        var field = $scope.editor.field;
+        let field = $scope.editor.field;
 
         if (!field || !field.format) {
           return;
         }
 
         Promise.try(function () {
-          var converter = field.format.getConverterFor('html');
+          let converter = field.format.getConverterFor('html');
           $scope.samples = _.map($scope.inputs, function (input) {
             return [input, $sce.trustAsHtml(converter(input))];
           });
diff --git a/src/ui/public/filter_bar/filter_bar.js b/src/ui/public/filter_bar/filter_bar.js
index d50a33d3b08e4..d16b64332c0e9 100644
--- a/src/ui/public/filter_bar/filter_bar.js
+++ b/src/ui/public/filter_bar/filter_bar.js
@@ -11,17 +11,17 @@ import FilterBarLibFilterOutTimeBasedFilterProvider from 'ui/filter_bar/lib/filt
 import FilterBarLibChangeTimeFilterProvider from 'ui/filter_bar/lib/change_time_filter';
 import FilterBarQueryFilterProvider from 'ui/filter_bar/query_filter';
 import uiModules from 'ui/modules';
-var module = uiModules.get('kibana');
+let module = uiModules.get('kibana');
 
 
 module.directive('filterBar', function (Private, Promise, getAppState) {
-  var mapAndFlattenFilters = Private(FilterBarLibMapAndFlattenFiltersProvider);
-  var mapFlattenAndWrapFilters = Private(FilterBarLibMapFlattenAndWrapFiltersProvider);
-  var extractTimeFilter = Private(FilterBarLibExtractTimeFilterProvider);
-  var filterOutTimeBasedFilter = Private(FilterBarLibFilterOutTimeBasedFilterProvider);
-  var changeTimeFilter = Private(FilterBarLibChangeTimeFilterProvider);
-  var queryFilter = Private(FilterBarQueryFilterProvider);
-  var privateFilterFieldRegex = /(^\$|meta)/;
+  let mapAndFlattenFilters = Private(FilterBarLibMapAndFlattenFiltersProvider);
+  let mapFlattenAndWrapFilters = Private(FilterBarLibMapFlattenAndWrapFiltersProvider);
+  let extractTimeFilter = Private(FilterBarLibExtractTimeFilterProvider);
+  let filterOutTimeBasedFilter = Private(FilterBarLibFilterOutTimeBasedFilterProvider);
+  let changeTimeFilter = Private(FilterBarLibChangeTimeFilterProvider);
+  let queryFilter = Private(FilterBarQueryFilterProvider);
+  let privateFilterFieldRegex = /(^\$|meta)/;
 
   return {
     restrict: 'E',
@@ -48,7 +48,7 @@ module.directive('filterBar', function (Private, Promise, getAppState) {
 
       $scope.aceLoaded = function (editor) {
         editor.$blockScrolling = Infinity;
-        var session = editor.getSession();
+        let session = editor.getSession();
         session.setTabSize(2);
         session.setUseSoftTabs(true);
       };
@@ -141,7 +141,7 @@ module.directive('filterBar', function (Private, Promise, getAppState) {
       }
 
       function updateFilters() {
-        var filters = queryFilter.getFilters();
+        let filters = queryFilter.getFilters();
         mapAndFlattenFilters(filters).then(function (results) {
           // used to display the current filters in the state
           $scope.filters = _.sortBy(results, function (filter) {
diff --git a/src/ui/public/filter_bar/filter_bar_click_handler.js b/src/ui/public/filter_bar/filter_bar_click_handler.js
index d5396b593e21b..25c7ae1a3b1bf 100644
--- a/src/ui/public/filter_bar/filter_bar_click_handler.js
+++ b/src/ui/public/filter_bar/filter_bar_click_handler.js
@@ -6,7 +6,7 @@ import findByParam from 'ui/utils/find_by_param';
 export default function (Notifier) {
   return function ($state) {
     return function (event, simulate) {
-      var notify = new Notifier({
+      let notify = new Notifier({
         location: 'Filter bar'
       });
       let aggConfigResult;
@@ -23,18 +23,18 @@ export default function (Notifier) {
       }
 
       if (aggConfigResult) {
-        var isLegendLabel = !!event.point.values;
-        var aggBuckets = _.filter(aggConfigResult.getPath(), { type: 'bucket' });
+        let isLegendLabel = !!event.point.values;
+        let aggBuckets = _.filter(aggConfigResult.getPath(), { type: 'bucket' });
 
         // For legend clicks, use the last bucket in the path
         if (isLegendLabel) {
           // series data has multiple values, use aggConfig on the first
           // hierarchical data values is an object with the addConfig
-          var aggConfig = findByParam(event.point.values, 'aggConfig');
+          let aggConfig = findByParam(event.point.values, 'aggConfig');
           aggBuckets = aggBuckets.filter((result) => result.aggConfig && result.aggConfig === aggConfig);
         }
 
-        var filters = _(aggBuckets)
+        let filters = _(aggBuckets)
         .map(function (result) {
           try {
             return result.createFilter();
diff --git a/src/ui/public/filter_bar/lib/change_time_filter.js b/src/ui/public/filter_bar/lib/change_time_filter.js
index 166f6a274516d..47e991eabe7be 100644
--- a/src/ui/public/filter_bar/lib/change_time_filter.js
+++ b/src/ui/public/filter_bar/lib/change_time_filter.js
@@ -2,8 +2,8 @@ import moment from 'moment';
 import _ from 'lodash';
 export default function changeTimeFilterProvider(timefilter) {
   return function (filter) {
-    var key = _.keys(filter.range)[0];
-    var values = filter.range[key];
+    let key = _.keys(filter.range)[0];
+    let values = filter.range[key];
     timefilter.time.from = moment(values.gt || values.gte);
     timefilter.time.to = moment(values.lt || values.lte);
     timefilter.time.mode = 'absolute';
diff --git a/src/ui/public/filter_bar/lib/compare_filters.js b/src/ui/public/filter_bar/lib/compare_filters.js
index a9edc75c9a04a..2cfa19e6d5345 100644
--- a/src/ui/public/filter_bar/lib/compare_filters.js
+++ b/src/ui/public/filter_bar/lib/compare_filters.js
@@ -24,7 +24,7 @@ export default function (first, second, comparatorOptions) {
 };
 
 function mapFilter(filter) {
-  var cleaned = _.omit(filter, excludedAttributes);
+  let cleaned = _.omit(filter, excludedAttributes);
   if (comparators.negate) cleaned.negate = filter.meta && !!filter.meta.negate;
   if (comparators.disabled) cleaned.disabled = filter.meta && !!filter.meta.disabled;
   return cleaned;
diff --git a/src/ui/public/filter_bar/lib/extract_time_filter.js b/src/ui/public/filter_bar/lib/extract_time_filter.js
index b3e431451df4c..c13b96a4ffa25 100644
--- a/src/ui/public/filter_bar/lib/extract_time_filter.js
+++ b/src/ui/public/filter_bar/lib/extract_time_filter.js
@@ -3,12 +3,12 @@ export default function extractTimeFilterProvider(courier, Promise) {
   return Promise.method(function (filters) {
     // Assume all the index patterns are the same since they will be added
     // from the same visualization.
-    var id = _.get(filters, '[0].meta.index');
+    let id = _.get(filters, '[0].meta.index');
     if (id == null) return;
 
     return courier.indexPatterns.get(id).then(function (indexPattern) {
-      var filter = _.find(filters, function (obj) {
-        var key = _.keys(obj.range)[0];
+      let filter = _.find(filters, function (obj) {
+        let key = _.keys(obj.range)[0];
         return key === indexPattern.timeFieldName;
       });
       if (filter && filter.range) {
diff --git a/src/ui/public/filter_bar/lib/filter_out_time_based_filter.js b/src/ui/public/filter_bar/lib/filter_out_time_based_filter.js
index 489ecd8b2a2f3..bd033b15fd8d5 100644
--- a/src/ui/public/filter_bar/lib/filter_out_time_based_filter.js
+++ b/src/ui/public/filter_bar/lib/filter_out_time_based_filter.js
@@ -1,7 +1,7 @@
 import _ from 'lodash';
 export default function filterOutTimeBaseFilter(courier, Promise) {
   return Promise.method(function (filters) {
-    var id = _.get(filters, '[0].meta.index');
+    let id = _.get(filters, '[0].meta.index');
     if (id == null) return;
 
     return courier.indexPatterns.get(id).then(function (indexPattern) {
diff --git a/src/ui/public/filter_bar/lib/generate_mapping_chain.js b/src/ui/public/filter_bar/lib/generate_mapping_chain.js
index 9e0a32f9a9756..e857804a37775 100644
--- a/src/ui/public/filter_bar/lib/generate_mapping_chain.js
+++ b/src/ui/public/filter_bar/lib/generate_mapping_chain.js
@@ -1,7 +1,7 @@
 import _ from 'lodash';
 export default function generateMappingChainProvider(Promise) {
 
-  var noop = function () {
+  let noop = function () {
     return Promise.reject(new Error('No mappings have been found for filter.'));
   };
 
diff --git a/src/ui/public/filter_bar/lib/map_and_flatten_filters.js b/src/ui/public/filter_bar/lib/map_and_flatten_filters.js
index f8d2820cd0454..f48706eb68f88 100644
--- a/src/ui/public/filter_bar/lib/map_and_flatten_filters.js
+++ b/src/ui/public/filter_bar/lib/map_and_flatten_filters.js
@@ -1,7 +1,7 @@
 import _ from 'lodash';
 import FilterBarLibMapFilterProvider from 'ui/filter_bar/lib/map_filter';
 export default function mapAndFlattenFiltersProvider(Private, Promise) {
-  var mapFilter = Private(FilterBarLibMapFilterProvider);
+  let mapFilter = Private(FilterBarLibMapFilterProvider);
   return function (filters) {
     return _(filters)
     .flatten()
diff --git a/src/ui/public/filter_bar/lib/map_default.js b/src/ui/public/filter_bar/lib/map_default.js
index 18d68489073ea..e9f53ed21710e 100644
--- a/src/ui/public/filter_bar/lib/map_default.js
+++ b/src/ui/public/filter_bar/lib/map_default.js
@@ -2,15 +2,15 @@ import angular from 'angular';
 import _ from 'lodash';
 export default function mapDefaultProvider(Promise) {
 
-  var metaProperty = /(^\$|meta)/;
+  let metaProperty = /(^\$|meta)/;
 
   return function (filter) {
-    var key = _.find(_.keys(filter), function (key) {
+    let key = _.find(_.keys(filter), function (key) {
       return !key.match(metaProperty);
     });
 
     if (key) {
-      var value = angular.toJson(filter[key]);
+      let value = angular.toJson(filter[key]);
       return Promise.resolve({ key: key, value: value });
     }
     return Promise.reject(filter);
diff --git a/src/ui/public/filter_bar/lib/map_filter.js b/src/ui/public/filter_bar/lib/map_filter.js
index 79291f97b8442..7b80d2176a8d1 100644
--- a/src/ui/public/filter_bar/lib/map_filter.js
+++ b/src/ui/public/filter_bar/lib/map_filter.js
@@ -11,7 +11,7 @@ import MapScriptProvider from './map_script';
 import MapDefaultProvider from './map_default';
 export default function mapFilterProvider(Promise, Private) {
 
-  var generateMappingChain = Private(GenerateMappingChainProvider);
+  let generateMappingChain = Private(GenerateMappingChainProvider);
 
   /** Mappers **/
 
@@ -29,7 +29,7 @@ export default function mapFilterProvider(Promise, Private) {
   // To create a new mapper you just need to create a function
   // that either handles the mapping operation or not
   // and add it here. ProTip: These are executed in order listed
-  var mappers = [
+  let mappers = [
     Private(MapMatchAllProvider),
     Private(MapTermsProvider),
     Private(MapRangeProvider),
@@ -41,14 +41,14 @@ export default function mapFilterProvider(Promise, Private) {
     Private(MapDefaultProvider)
   ];
 
-  var noop = function () {
+  let noop = function () {
     return Promise.reject(new Error('No mappings have been found for filter.'));
   };
 
   // Create a chain of responsibility by reducing all the
   // mappers down into one function.
-  var mapFn = _.reduceRight(mappers, function (memo, map) {
-    var filterChainFn = generateMappingChain(map);
+  let mapFn = _.reduceRight(mappers, function (memo, map) {
+    let filterChainFn = generateMappingChain(map);
     return filterChainFn(memo);
   }, noop);
 
diff --git a/src/ui/public/filter_bar/lib/map_flatten_and_wrap_filters.js b/src/ui/public/filter_bar/lib/map_flatten_and_wrap_filters.js
index da726135aba64..f86b5a6e566b1 100644
--- a/src/ui/public/filter_bar/lib/map_flatten_and_wrap_filters.js
+++ b/src/ui/public/filter_bar/lib/map_flatten_and_wrap_filters.js
@@ -1,7 +1,7 @@
 import _ from 'lodash';
 import FilterBarLibMapAndFlattenFiltersProvider from 'ui/filter_bar/lib/map_and_flatten_filters';
 export default function mapFlattenAndWrapFilters(Private) {
-  var mapAndFlattenFilters = Private(FilterBarLibMapAndFlattenFiltersProvider);
+  let mapAndFlattenFilters = Private(FilterBarLibMapAndFlattenFiltersProvider);
   return function (filters) {
     return mapAndFlattenFilters(filters).then(function (filters) {
       return _.map(filters, function (filter) {
diff --git a/src/ui/public/filter_bar/lib/map_range.js b/src/ui/public/filter_bar/lib/map_range.js
index 12a3cd96a2c64..5e710b0dd4560 100644
--- a/src/ui/public/filter_bar/lib/map_range.js
+++ b/src/ui/public/filter_bar/lib/map_range.js
@@ -7,14 +7,14 @@ export default function mapRangeProvider(Promise, courier) {
     .indexPatterns
     .get(filter.meta.index)
     .then(function (indexPattern) {
-      var key = Object.keys(filter.range)[0];
-      var convert = indexPattern.fields.byName[key].format.getConverterFor('text');
-      var range = filter.range[key];
+      let key = Object.keys(filter.range)[0];
+      let convert = indexPattern.fields.byName[key].format.getConverterFor('text');
+      let range = filter.range[key];
 
-      var left = has(range, 'gte') ? range.gte : range.gt;
+      let left = has(range, 'gte') ? range.gte : range.gt;
       if (left == null) left = -Infinity;
 
-      var right = has(range, 'lte') ? range.lte : range.lt;
+      let right = has(range, 'lte') ? range.lte : range.lt;
       if (right == null) right = Infinity;
 
       return {
diff --git a/src/ui/public/filter_bar/lib/only_disabled.js b/src/ui/public/filter_bar/lib/only_disabled.js
index 002a0ff304793..8bb7cbf23ee91 100644
--- a/src/ui/public/filter_bar/lib/only_disabled.js
+++ b/src/ui/public/filter_bar/lib/only_disabled.js
@@ -1,6 +1,6 @@
 import _ from 'lodash';
 
-var pluckDisabled = function (filter) {
+let pluckDisabled = function (filter) {
   return _.get(filter, 'meta.disabled');
 };
 
diff --git a/src/ui/public/filter_bar/lib/only_state_changed.js b/src/ui/public/filter_bar/lib/only_state_changed.js
index 2b3a7ad9723bd..8fe0cceec830a 100644
--- a/src/ui/public/filter_bar/lib/only_state_changed.js
+++ b/src/ui/public/filter_bar/lib/only_state_changed.js
@@ -1,6 +1,6 @@
 import _ from 'lodash';
 import compareFilters from 'ui/filter_bar/lib/compare_filters';
-var compareOptions = { disabled: true, negate: true };
+let compareOptions = { disabled: true, negate: true };
 
 /**
  * Checks to see if only disabled filters have been changed
@@ -8,7 +8,7 @@ var compareOptions = { disabled: true, negate: true };
  */
 export default function (newFilters, oldFilters) {
   return _.every(newFilters, function (newFilter, i) {
-    var match = _.find(oldFilters, function (oldFilter) {
+    let match = _.find(oldFilters, function (oldFilter) {
       return compareFilters(newFilter, oldFilter, compareOptions);
     });
     return !!match;
diff --git a/src/ui/public/filter_bar/lib/uniq_filters.js b/src/ui/public/filter_bar/lib/uniq_filters.js
index 988f921af7b37..cdaa896b55a09 100644
--- a/src/ui/public/filter_bar/lib/uniq_filters.js
+++ b/src/ui/public/filter_bar/lib/uniq_filters.js
@@ -7,7 +7,7 @@ import dedupFilters from 'ui/filter_bar/lib/dedup_filters';
  * @returns {object} The original filters array with duplicates removed
  */
 export default function (filters, comparatorOptions) {
-  var results = [];
+  let results = [];
   _.each(filters, function (filter) {
     results = _.union(results, dedupFilters(results, [filter], comparatorOptions));
   });
diff --git a/src/ui/public/filter_bar/push_filter.js b/src/ui/public/filter_bar/push_filter.js
index 3b75d263af5fe..6375791b05826 100644
--- a/src/ui/public/filter_bar/push_filter.js
+++ b/src/ui/public/filter_bar/push_filter.js
@@ -7,8 +7,8 @@ export default function () {
       // Hierarchical and tabular data set their aggConfigResult parameter
       // differently because of how the point is rewritten between the two. So
       // we need to check if the point.orig is set, if not use try the point.aggConfigResult
-      var filters = _.clone($state.filters || []);
-      var pendingFilter = { meta: { negate: negate, index: index }};
+      let filters = _.clone($state.filters || []);
+      let pendingFilter = { meta: { negate: negate, index: index }};
       _.extend(pendingFilter, filter);
       filters.push(pendingFilter);
       $state.filters = filters;
diff --git a/src/ui/public/filter_bar/query_filter.js b/src/ui/public/filter_bar/query_filter.js
index 501de4a26f18e..7647586b0c44f 100644
--- a/src/ui/public/filter_bar/query_filter.js
+++ b/src/ui/public/filter_bar/query_filter.js
@@ -8,21 +8,21 @@ import EventsProvider from 'ui/events';
 import FilterBarLibMapAndFlattenFiltersProvider from 'ui/filter_bar/lib/map_and_flatten_filters';
 
 export default function (Private, $rootScope, getAppState, globalState, config) {
-  var EventEmitter = Private(EventsProvider);
-  var mapAndFlattenFilters = Private(FilterBarLibMapAndFlattenFiltersProvider);
+  let EventEmitter = Private(EventsProvider);
+  let mapAndFlattenFilters = Private(FilterBarLibMapAndFlattenFiltersProvider);
 
-  var queryFilter = new EventEmitter();
+  let queryFilter = new EventEmitter();
 
   queryFilter.getFilters = function () {
-    var compareOptions = { disabled: true, negate: true };
-    var appFilters = queryFilter.getAppFilters();
-    var globalFilters = queryFilter.getGlobalFilters();
+    let compareOptions = { disabled: true, negate: true };
+    let appFilters = queryFilter.getAppFilters();
+    let globalFilters = queryFilter.getGlobalFilters();
 
     return uniqFilters(globalFilters.concat(appFilters), compareOptions);
   };
 
   queryFilter.getAppFilters = function () {
-    var appState = getAppState();
+    let appState = getAppState();
     if (!appState || !appState.filters) return [];
 
     // Work around for https://github.com/elastic/kibana/issues/5896
@@ -49,7 +49,7 @@ export default function (Private, $rootScope, getAppState, globalState, config)
   queryFilter.addFilters = function (filters, global) {
 
     if (global === undefined) {
-      var configDefault = config.get('filters:pinnedByDefault');
+      let configDefault = config.get('filters:pinnedByDefault');
 
       if (configDefault === false || configDefault === true) {
         global = configDefault;
@@ -57,8 +57,8 @@ export default function (Private, $rootScope, getAppState, globalState, config)
     }
 
     // Determine the state for the new filter (whether to pass the filter through other apps or not)
-    var appState = getAppState();
-    var filterState = (global) ? globalState : appState;
+    let appState = getAppState();
+    let filterState = (global) ? globalState : appState;
 
     if (!_.isArray(filters)) {
       filters = [filters];
@@ -79,8 +79,8 @@ export default function (Private, $rootScope, getAppState, globalState, config)
    * @param {object} matchFilter The filter to remove
    */
   queryFilter.removeFilter = function (matchFilter) {
-    var appState = getAppState();
-    var filter = _.omit(matchFilter, ['$$hashKey']);
+    let appState = getAppState();
+    let filter = _.omit(matchFilter, ['$$hashKey']);
     let state;
     let index;
 
@@ -108,11 +108,11 @@ export default function (Private, $rootScope, getAppState, globalState, config)
   * @returns {object} Promise that resolves to the new filter on a successful merge
   */
   queryFilter.updateFilter = function (filter) {
-    var mergedFilter = _.assign({}, filter.source, filter.model);
+    let mergedFilter = _.assign({}, filter.source, filter.model);
     mergedFilter.meta.alias = filter.alias;
     //If the filter type is changed we want to discard the old type
     //when merging changes back in
-    var filterTypeReplaced = filter.model[filter.type] !== mergedFilter[filter.type];
+    let filterTypeReplaced = filter.model[filter.type] !== mergedFilter[filter.type];
     if (filterTypeReplaced) {
       delete mergedFilter[filter.type];
     }
@@ -124,7 +124,7 @@ export default function (Private, $rootScope, getAppState, globalState, config)
    * Removes all filters
    */
   queryFilter.removeAll = function () {
-    var appState = getAppState();
+    let appState = getAppState();
     appState.filters = [];
     globalState.filters = [];
   };
@@ -137,7 +137,7 @@ export default function (Private, $rootScope, getAppState, globalState, config)
    */
   queryFilter.toggleFilter = function (filter, force) {
     // Toggle the disabled flag
-    var disabled = _.isUndefined(force) ? !filter.meta.disabled : !!force;
+    let disabled = _.isUndefined(force) ? !filter.meta.disabled : !!force;
     filter.meta.disabled = disabled;
     return filter;
   };
@@ -182,20 +182,20 @@ export default function (Private, $rootScope, getAppState, globalState, config)
    * @returns {object} updated filter
    */
   queryFilter.pinFilter = function (filter, force) {
-    var appState = getAppState();
+    let appState = getAppState();
     if (!appState) return filter;
 
     // ensure that both states have a filters property
     if (!_.isArray(globalState.filters)) globalState.filters = [];
     if (!_.isArray(appState.filters)) appState.filters = [];
 
-    var appIndex = _.indexOf(appState.filters, filter);
+    let appIndex = _.indexOf(appState.filters, filter);
 
     if (appIndex !== -1 && force !== false) {
       appState.filters.splice(appIndex, 1);
       globalState.filters.push(filter);
     } else {
-      var globalIndex = _.indexOf(globalState.filters, filter);
+      let globalIndex = _.indexOf(globalState.filters, filter);
 
       if (globalIndex === -1 || force === true) return filter;
 
@@ -226,7 +226,7 @@ export default function (Private, $rootScope, getAppState, globalState, config)
    * Rids filter list of null values and replaces state if any nulls are found
    */
   function validateStateFilters(state) {
-    var compacted = _.compact(state.filters);
+    let compacted = _.compact(state.filters);
     if (state.filters.length !== compacted.length) {
       state.filters = compacted;
       state.replace();
@@ -240,7 +240,7 @@ export default function (Private, $rootScope, getAppState, globalState, config)
    * @returns {object} Resulting filter list, app and global combined
    */
   function saveState() {
-    var appState = getAppState();
+    let appState = getAppState();
     if (appState) appState.save();
     globalState.save();
   }
@@ -256,9 +256,9 @@ export default function (Private, $rootScope, getAppState, globalState, config)
 
   // helper to run a function on all filters in all states
   function executeOnFilters(fn) {
-    var appState = getAppState();
-    var globalFilters = [];
-    var appFilters = [];
+    let appState = getAppState();
+    let globalFilters = [];
+    let appFilters = [];
 
     if (globalState.filters) globalFilters = globalState.filters;
     if (appState && appState.filters) appFilters = appState.filters;
@@ -268,13 +268,13 @@ export default function (Private, $rootScope, getAppState, globalState, config)
 
   function mergeStateFilters(gFilters, aFilters, compareOptions) {
     // ensure we don't mutate the filters passed in
-    var globalFilters = gFilters ? _.cloneDeep(gFilters) : [];
-    var appFilters = aFilters ? _.cloneDeep(aFilters) : [];
+    let globalFilters = gFilters ? _.cloneDeep(gFilters) : [];
+    let appFilters = aFilters ? _.cloneDeep(aFilters) : [];
     compareOptions = _.defaults(compareOptions || {}, { disabled: true });
 
     // existing globalFilters should be mutated by appFilters
     _.each(appFilters, function (filter, i) {
-      var match = _.find(globalFilters, function (globalFilter) {
+      let match = _.find(globalFilters, function (globalFilter) {
         return compareFilters(globalFilter, filter, compareOptions);
       });
 
@@ -306,7 +306,7 @@ export default function (Private, $rootScope, getAppState, globalState, config)
 
     function initAppStateWatchers() {
       // multi watch on the app and global states
-      var stateWatchers = [{
+      let stateWatchers = [{
         fn: $rootScope.$watch,
         deep: true,
         get: queryFilter.getGlobalFilters
@@ -321,18 +321,18 @@ export default function (Private, $rootScope, getAppState, globalState, config)
         // prevent execution on watcher instantiation
         if (_.isEqual(next, prev)) return;
 
-        var doUpdate = false;
-        var doFetch = false;
+        let doUpdate = false;
+        let doFetch = false;
 
         // reconcile filter in global and app states
-        var filters = mergeStateFilters(next[0], next[1]);
-        var globalFilters = filters[0];
-        var appFilters = filters[1];
-        var appState = getAppState();
+        let filters = mergeStateFilters(next[0], next[1]);
+        let globalFilters = filters[0];
+        let appFilters = filters[1];
+        let appState = getAppState();
 
         // save the state, as it may have updated
-        var globalChanged = !_.isEqual(next[0], globalFilters);
-        var appChanged = !_.isEqual(next[1], appFilters);
+        let globalChanged = !_.isEqual(next[0], globalFilters);
+        let appChanged = !_.isEqual(next[1], appFilters);
 
         // the filters were changed, apply to state (re-triggers this watcher)
         if (globalChanged || appChanged) {
@@ -355,12 +355,12 @@ export default function (Private, $rootScope, getAppState, globalState, config)
 
         // iterate over each state type, checking for changes
         function getActions() {
-          var newFilters = [];
-          var oldFilters = [];
+          let newFilters = [];
+          let oldFilters = [];
 
           stateWatchers.forEach(function (watcher, i) {
-            var nextVal = next[i];
-            var prevVal = prev[i];
+            let nextVal = next[i];
+            let prevVal = prev[i];
             newFilters = newFilters.concat(nextVal);
             oldFilters = oldFilters.concat(prevVal);
 
diff --git a/src/ui/public/filter_manager/filter_manager.js b/src/ui/public/filter_manager/filter_manager.js
index 9f4584fdb91aa..e6c93fbf8a311 100644
--- a/src/ui/public/filter_manager/filter_manager.js
+++ b/src/ui/public/filter_manager/filter_manager.js
@@ -2,21 +2,21 @@ import _ from 'lodash';
 import FilterBarQueryFilterProvider from 'ui/filter_bar/query_filter';
 // Adds a filter to a passed state
 export default function (Private) {
-  var queryFilter = Private(FilterBarQueryFilterProvider);
-  var filterManager = {};
+  let queryFilter = Private(FilterBarQueryFilterProvider);
+  let filterManager = {};
 
   filterManager.add = function (field, values, operation, index) {
     values = _.isArray(values) ? values : [values];
-    var fieldName = _.isObject(field) ? field.name : field;
-    var filters = _.flatten([queryFilter.getAppFilters()]);
-    var newFilters = [];
+    let fieldName = _.isObject(field) ? field.name : field;
+    let filters = _.flatten([queryFilter.getAppFilters()]);
+    let newFilters = [];
 
-    var negate = (operation === '-');
+    let negate = (operation === '-');
 
     // TODO: On array fields, negating does not negate the combination, rather all terms
     _.each(values, function (value) {
       let filter;
-      var existing = _.find(filters, function (filter) {
+      let existing = _.find(filters, function (filter) {
         if (!filter) return;
 
         if (fieldName === '_exists_' && filter.exists) {
diff --git a/src/ui/public/filter_manager/lib/phrase.js b/src/ui/public/filter_manager/lib/phrase.js
index 2fcd3cb18c053..9cbde5b2ca0b2 100644
--- a/src/ui/public/filter_manager/lib/phrase.js
+++ b/src/ui/public/filter_manager/lib/phrase.js
@@ -1,6 +1,6 @@
 import _ from 'lodash';
 export default function buildPhraseFilter(field, value, indexPattern) {
-  var filter = { meta: { index: indexPattern.id} };
+  let filter = { meta: { index: indexPattern.id} };
 
   if (field.scripted) {
     filter.script = {
diff --git a/src/ui/public/filters/_prop_filter.js b/src/ui/public/filters/_prop_filter.js
index fca3db02af928..19d817df80662 100644
--- a/src/ui/public/filters/_prop_filter.js
+++ b/src/ui/public/filters/_prop_filter.js
@@ -23,9 +23,9 @@ function propFilter(prop) {
     if (!_.isArray(filters)) filters = filters.split(',');
     if (_.contains(filters, '*')) return list;
 
-    var options = filters.reduce(function (options, filter) {
-      var type = 'include';
-      var value = filter;
+    let options = filters.reduce(function (options, filter) {
+      let type = 'include';
+      let value = filter;
 
       if (filter.charAt(0) === '!') {
         type = 'exclude';
@@ -38,12 +38,12 @@ function propFilter(prop) {
     }, {});
 
     return list.filter(function (item) {
-      var value = item[prop];
+      let value = item[prop];
 
-      var excluded = options.exclude && _.contains(options.exclude, value);
+      let excluded = options.exclude && _.contains(options.exclude, value);
       if (excluded) return false;
 
-      var included = !options.include || _.contains(options.include, value);
+      let included = !options.include || _.contains(options.include, value);
       if (included) return true;
 
       return false;
diff --git a/src/ui/public/filters/comma_list.js b/src/ui/public/filters/comma_list.js
index 12acb8daa6602..febe90384585f 100644
--- a/src/ui/public/filters/comma_list.js
+++ b/src/ui/public/filters/comma_list.js
@@ -13,12 +13,12 @@ uiModules
    * @return {String}
    */
   return function (input, inclusive) {
-    var list = _.commaSeperatedList(input);
+    let list = _.commaSeperatedList(input);
     if (list.length < 2) {
       return list.join('');
     }
 
-    var conj = inclusive ? ' and ' : ' or ';
+    let conj = inclusive ? ' and ' : ' or ';
     return list.slice(0, -1).join(', ') + conj + _.last(list);
 
   };
diff --git a/src/ui/public/filters/match_any.js b/src/ui/public/filters/match_any.js
index e9659b5c109be..5d7ff8329091c 100644
--- a/src/ui/public/filters/match_any.js
+++ b/src/ui/public/filters/match_any.js
@@ -13,7 +13,7 @@ uiModules
     }
 
     return _.filter(items, function (item) {
-      for (var i = 0; i < rules.length; i++) {
+      for (let i = 0; i < rules.length; i++) {
         if (_.some([item], rules[i])) {
           return true;
         }
diff --git a/src/ui/public/filters/moment.js b/src/ui/public/filters/moment.js
index c6bdc61decde8..9209709a395d2 100644
--- a/src/ui/public/filters/moment.js
+++ b/src/ui/public/filters/moment.js
@@ -6,7 +6,7 @@ uiModules
   .get('kibana')
   .filter('moment', function (config) {
     return function (datetime) {
-      var format = config.get('dateFormat');
+      let format = config.get('dateFormat');
       if (moment.isMoment(datetime)) return datetime.format(format);
       if (_.isDate(datetime)) return moment(datetime).format(format);
       return datetime;
diff --git a/src/ui/public/filters/rison.js b/src/ui/public/filters/rison.js
index 9b5c5433ff4ad..f88a05c2e19d8 100644
--- a/src/ui/public/filters/rison.js
+++ b/src/ui/public/filters/rison.js
@@ -1,6 +1,6 @@
 import rison from 'ui/utils/rison';
 import uiModules from 'ui/modules';
-var module = uiModules.get('kibana');
+let module = uiModules.get('kibana');
 
 module.filter('rison', function () {
   return function (str) {
diff --git a/src/ui/public/filters/trust_as_html.js b/src/ui/public/filters/trust_as_html.js
index 046f30de6cbf8..e622294557d33 100644
--- a/src/ui/public/filters/trust_as_html.js
+++ b/src/ui/public/filters/trust_as_html.js
@@ -1,6 +1,6 @@
 import angular from 'angular';
 import uiModules from 'ui/modules';
-var module = uiModules.get('kibana');
+let module = uiModules.get('kibana');
 
 // Simple filter to allow using ng-bind-html without explicitly calling $sce.trustAsHtml in a controller
 // (See http://goo.gl/mpj9o2)
diff --git a/src/ui/public/filters/unique.js b/src/ui/public/filters/unique.js
index 15948bbda7bea..643ae819f591d 100644
--- a/src/ui/public/filters/unique.js
+++ b/src/ui/public/filters/unique.js
@@ -6,7 +6,7 @@ uiModules
   .get('kibana')
   .filter('unique', function () {
     return function (arr) {
-      var list = _.unique(arr);
+      let list = _.unique(arr);
       return list;
     };
   });
diff --git a/src/ui/public/highlight/highlight.js b/src/ui/public/highlight/highlight.js
index a7660f1f3a801..f51a3ae2bfb52 100644
--- a/src/ui/public/highlight/highlight.js
+++ b/src/ui/public/highlight/highlight.js
@@ -3,7 +3,7 @@ import _ from 'lodash';
 import angular from 'angular';
 import uiModules from 'ui/modules';
 
-var module = uiModules.get('kibana');
+let module = uiModules.get('kibana');
 
 module.filter('highlight', function (highlightTags) {
   return function (formatted, highlight) {
@@ -13,12 +13,12 @@ module.filter('highlight', function (highlightTags) {
       section = _.escape(section);
 
       // Strip out the highlight tags to compare against the formatted string
-      var untagged = section
+      let untagged = section
         .split(highlightTags.pre).join('')
         .split(highlightTags.post).join('');
 
       // Replace all highlight tags with proper html tags
-      var tagged = section
+      let tagged = section
         .split(highlightTags.pre).join('<mark>')
         .split(highlightTags.post).join('</mark>');
 
diff --git a/src/ui/public/highlight/highlight_tags.js b/src/ui/public/highlight/highlight_tags.js
index f47a4d696bc86..350357ec35b59 100644
--- a/src/ui/public/highlight/highlight_tags.js
+++ b/src/ui/public/highlight/highlight_tags.js
@@ -1,5 +1,5 @@
 import uiModules from 'ui/modules';
-var module = uiModules.get('kibana');
+let module = uiModules.get('kibana');
 
 // By default, ElasticSearch surrounds matched values in <em></em>. This is not ideal because it is possible that
 // the value could contain <em></em> in the value. We define these custom tags that we would never expect to see
diff --git a/src/ui/public/index_patterns/_cast_mapping_type.js b/src/ui/public/index_patterns/_cast_mapping_type.js
index 1453fa88b7259..760a67255a194 100644
--- a/src/ui/public/index_patterns/_cast_mapping_type.js
+++ b/src/ui/public/index_patterns/_cast_mapping_type.js
@@ -34,7 +34,7 @@ export default function CastMappingTypeFn() {
   function castMappingType(name) {
     if (!name) return 'unknown';
 
-    var match = castMappingType.types.byName[name];
+    let match = castMappingType.types.byName[name];
     return match ? match.type : 'string';
   }
 
diff --git a/src/ui/public/index_patterns/_ensure_some.js b/src/ui/public/index_patterns/_ensure_some.js
index 60e0f643809a5..ec97f3874926c 100644
--- a/src/ui/public/index_patterns/_ensure_some.js
+++ b/src/ui/public/index_patterns/_ensure_some.js
@@ -1,6 +1,6 @@
 import errors from 'ui/errors';
 export default function EnsureSomeIndexPatternsFn(Private, Notifier, $location, kbnUrl) {
-  var notify = new Notifier();
+  let notify = new Notifier();
 
   return function ensureSomeIndexPatterns() {
     return function promiseHandler(patterns) {
diff --git a/src/ui/public/index_patterns/_field.js b/src/ui/public/index_patterns/_field.js
index d20b23625dff3..a0c4e6a0cba98 100644
--- a/src/ui/public/index_patterns/_field.js
+++ b/src/ui/public/index_patterns/_field.js
@@ -3,10 +3,10 @@ import IndexPatternsFieldFormatFieldFormatProvider from 'ui/index_patterns/_fiel
 import IndexPatternsFieldTypesProvider from 'ui/index_patterns/_field_types';
 import RegistryFieldFormatsProvider from 'ui/registry/field_formats';
 export default function FieldObjectProvider(Private, shortDotsFilter, $rootScope, Notifier) {
-  var notify = new Notifier({ location: 'IndexPattern Field' });
-  var FieldFormat = Private(IndexPatternsFieldFormatFieldFormatProvider);
-  var fieldTypes = Private(IndexPatternsFieldTypesProvider);
-  var fieldFormats = Private(RegistryFieldFormatsProvider);
+  let notify = new Notifier({ location: 'IndexPattern Field' });
+  let FieldFormat = Private(IndexPatternsFieldFormatFieldFormatProvider);
+  let fieldTypes = Private(IndexPatternsFieldTypesProvider);
+  let fieldFormats = Private(RegistryFieldFormatsProvider);
 
   function Field(indexPattern, spec) {
     // unwrap old instances of Field
@@ -15,14 +15,14 @@ export default function FieldObjectProvider(Private, shortDotsFilter, $rootScope
     // constuct this object using ObjDefine class, which
     // extends the Field.prototype but gets it's properties
     // defined using the logic below
-    var obj = new ObjDefine(spec, Field.prototype);
+    let obj = new ObjDefine(spec, Field.prototype);
 
     if (spec.name === '_source') {
       spec.type = '_source';
     }
 
     // find the type for this field, fallback to unknown type
-    var type = fieldTypes.byName[spec.type];
+    let type = fieldTypes.byName[spec.type];
     if (spec.type && !type) {
       notify.error(
         'Unknown field type "' + spec.type + '"' +
@@ -33,15 +33,15 @@ export default function FieldObjectProvider(Private, shortDotsFilter, $rootScope
 
     if (!type) type = fieldTypes.byName.unknown;
 
-    var format = spec.format;
+    let format = spec.format;
     if (!format || !(format instanceof FieldFormat)) {
       format = indexPattern.fieldFormatMap[spec.name] || fieldFormats.getDefaultInstance(spec.type);
     }
 
-    var indexed = !!spec.indexed;
-    var scripted = !!spec.scripted;
-    var sortable = spec.name === '_score' || ((indexed || scripted) && type.sortable);
-    var filterable = spec.name === '_id' || scripted || (indexed && type.filterable);
+    let indexed = !!spec.indexed;
+    let scripted = !!spec.scripted;
+    let sortable = spec.name === '_score' || ((indexed || scripted) && type.sortable);
+    let filterable = spec.name === '_id' || scripted || (indexed && type.filterable);
 
     obj.fact('name');
     obj.fact('type');
diff --git a/src/ui/public/index_patterns/_field_format/content_types.js b/src/ui/public/index_patterns/_field_format/content_types.js
index a49f1d3ad6742..ed82f0210c1f0 100644
--- a/src/ui/public/index_patterns/_field_format/content_types.js
+++ b/src/ui/public/index_patterns/_field_format/content_types.js
@@ -3,7 +3,7 @@ import angular from 'angular';
 import 'ui/highlight';
 export default function contentTypesProvider(highlightFilter) {
 
-  var types = {
+  let types = {
     html: function (format, convert) {
       return function recurse(value, field, hit) {
         if (value == null) {
@@ -14,10 +14,10 @@ export default function contentTypesProvider(highlightFilter) {
           return convert.call(format, value, field, hit);
         }
 
-        var subVals = value.map(function (v) {
+        let subVals = value.map(function (v) {
           return recurse(v, field, hit);
         });
-        var useMultiLine = subVals.some(function (sub) {
+        let useMultiLine = subVals.some(function (sub) {
           return sub.indexOf('\n') > -1;
         });
 
@@ -42,7 +42,7 @@ export default function contentTypesProvider(highlightFilter) {
   }
 
   function fallbackHtml(value, field, hit) {
-    var formatted = _.escape(this.convert(value, 'text'));
+    let formatted = _.escape(this.convert(value, 'text'));
 
     if (!hit || !hit.highlight || !hit.highlight[field.name]) {
       return formatted;
@@ -52,8 +52,8 @@ export default function contentTypesProvider(highlightFilter) {
   }
 
   function setup(format) {
-    var src = format._convert || {};
-    var converters = format._convert = {};
+    let src = format._convert || {};
+    let converters = format._convert = {};
 
     converters.text = types.text(format, src.text || fallbackText);
     converters.html = types.html(format, src.html || fallbackHtml);
diff --git a/src/ui/public/index_patterns/_field_format/field_format.js b/src/ui/public/index_patterns/_field_format/field_format.js
index cca0fb1ef4741..53b48c69985bd 100644
--- a/src/ui/public/index_patterns/_field_format/field_format.js
+++ b/src/ui/public/index_patterns/_field_format/field_format.js
@@ -1,10 +1,10 @@
 import _ from 'lodash';
 import IndexPatternsFieldFormatContentTypesProvider from 'ui/index_patterns/_field_format/content_types';
 export default function FieldFormatClassProvider(config, $rootScope, Private) {
-  var contentTypes = Private(IndexPatternsFieldFormatContentTypesProvider);
+  let contentTypes = Private(IndexPatternsFieldFormatContentTypesProvider);
 
   function FieldFormat(params) {
-    var self = this;
+    let self = this;
 
     // give the constructor a more appropriate name
     self.type = self.constructor;
@@ -59,7 +59,7 @@ export default function FieldFormatClassProvider(config, $rootScope, Private) {
    * @return {any}
    */
   FieldFormat.prototype.param = function (name) {
-    var val = this._params[name];
+    let val = this._params[name];
     if (val || val === false || val === 0) {
       // truthy, false, or 0 are fine
       // '', NaN, null, undefined, etc are not
@@ -84,10 +84,10 @@ export default function FieldFormatClassProvider(config, $rootScope, Private) {
    * @return {object}
    */
   FieldFormat.prototype.toJSON = function () {
-    var type = this.type;
-    var defaults = this._paramDefaults;
+    let type = this.type;
+    let defaults = this._paramDefaults;
 
-    var params = _.transform(this._params, function (uniqParams, val, param) {
+    let params = _.transform(this._params, function (uniqParams, val, param) {
       if (val !== defaults[param]) {
         uniqParams[param] = val;
       }
diff --git a/src/ui/public/index_patterns/_field_list.js b/src/ui/public/index_patterns/_field_list.js
index a55c27ad504ca..438159f334de6 100644
--- a/src/ui/public/index_patterns/_field_list.js
+++ b/src/ui/public/index_patterns/_field_list.js
@@ -2,7 +2,7 @@ import IndexedArray from 'ui/indexed_array';
 import _ from 'lodash';
 import IndexPatternsFieldProvider from 'ui/index_patterns/_field';
 export default function FieldListProvider(Private) {
-  var Field = Private(IndexPatternsFieldProvider);
+  let Field = Private(IndexPatternsFieldProvider);
 
   _.class(FieldList).inherits(IndexedArray);
   function FieldList(indexPattern, specs) {
diff --git a/src/ui/public/index_patterns/_flatten_hit.js b/src/ui/public/index_patterns/_flatten_hit.js
index 322d30234e585..9a09422c58c23 100644
--- a/src/ui/public/index_patterns/_flatten_hit.js
+++ b/src/ui/public/index_patterns/_flatten_hit.js
@@ -3,16 +3,16 @@ import _ from 'lodash';
 // returns a flattened version
 export default function FlattenHitProvider(config, $rootScope) {
 
-  var metaFields = config.get('metaFields');
+  let metaFields = config.get('metaFields');
   $rootScope.$on('change:config.metaFields', function () {
     metaFields = config.get('metaFields');
   });
 
   function flattenHit(indexPattern, hit) {
-    var flat = {};
+    let flat = {};
 
     // recursively merge _source
-    var fields = indexPattern.fields.byName;
+    let fields = indexPattern.fields.byName;
     (function flatten(obj, keyPrefix) {
       keyPrefix = keyPrefix ? keyPrefix + '.' : '';
       _.forOwn(obj, function (val, key) {
@@ -20,8 +20,8 @@ export default function FlattenHitProvider(config, $rootScope) {
 
         if (flat[key] !== void 0) return;
 
-        var hasValidMapping = (fields[key] && fields[key].type !== 'conflict');
-        var isValue = !_.isPlainObject(val);
+        let hasValidMapping = (fields[key] && fields[key].type !== 'conflict');
+        let isValue = !_.isPlainObject(val);
 
         if (hasValidMapping || isValue) {
           flat[key] = val;
diff --git a/src/ui/public/index_patterns/_format_hit.js b/src/ui/public/index_patterns/_format_hit.js
index b2bdbfde6faa4..d188952f33532 100644
--- a/src/ui/public/index_patterns/_format_hit.js
+++ b/src/ui/public/index_patterns/_format_hit.js
@@ -5,7 +5,7 @@ import _ from 'lodash';
 export default function (indexPattern, defaultFormat) {
 
   function convert(hit, val, fieldName) {
-    var field = indexPattern.fields.byName[fieldName];
+    let field = indexPattern.fields.byName[fieldName];
     if (!field) return defaultFormat.convert(val, 'html');
     return field.format.getConverterFor('html')(val, field, hit);
   }
@@ -15,12 +15,12 @@ export default function (indexPattern, defaultFormat) {
 
     // use and update the partial cache, but don't rewrite it. _source is stored in partials
     // but not $$_formatted
-    var partials = hit.$$_partialFormatted || (hit.$$_partialFormatted = {});
-    var cache = hit.$$_formatted = {};
+    let partials = hit.$$_partialFormatted || (hit.$$_partialFormatted = {});
+    let cache = hit.$$_formatted = {};
 
     _.forOwn(indexPattern.flattenHit(hit), function (val, fieldName) {
       // sync the formatted and partial cache
-      var formatted = partials[fieldName] == null ? convert(hit, val, fieldName) : partials[fieldName];
+      let formatted = partials[fieldName] == null ? convert(hit, val, fieldName) : partials[fieldName];
       cache[fieldName] = partials[fieldName] = formatted;
     });
 
@@ -28,7 +28,7 @@ export default function (indexPattern, defaultFormat) {
   }
 
   formatHit.formatField = function (hit, fieldName) {
-    var partials = hit.$$_partialFormatted;
+    let partials = hit.$$_partialFormatted;
     if (partials && partials[fieldName] != null) {
       return partials[fieldName];
     }
@@ -37,7 +37,7 @@ export default function (indexPattern, defaultFormat) {
       partials = hit.$$_partialFormatted = {};
     }
 
-    var val = fieldName === '_source' ? hit._source : indexPattern.flattenHit(hit)[fieldName];
+    let val = fieldName === '_source' ? hit._source : indexPattern.flattenHit(hit)[fieldName];
     return partials[fieldName] = convert(hit, val, fieldName);
   };
 
diff --git a/src/ui/public/index_patterns/_get_computed_fields.js b/src/ui/public/index_patterns/_get_computed_fields.js
index a7ce11bd044ac..f56f9af492a2d 100644
--- a/src/ui/public/index_patterns/_get_computed_fields.js
+++ b/src/ui/public/index_patterns/_get_computed_fields.js
@@ -2,9 +2,9 @@ import _ from 'lodash';
 // Takes a hit, merges it with any stored/scripted fields, and with the metaFields
 // returns a flattened version
 export default function () {
-  var self = this;
-  var scriptFields = {};
-  var fielddataFields = [];
+  let self = this;
+  let scriptFields = {};
+  let fielddataFields = [];
 
   fielddataFields = _.pluck(self.fields.byType.date, 'name');
 
diff --git a/src/ui/public/index_patterns/_get_ids.js b/src/ui/public/index_patterns/_get_ids.js
index a02d338f95d10..3f8ce6a716e16 100644
--- a/src/ui/public/index_patterns/_get_ids.js
+++ b/src/ui/public/index_patterns/_get_ids.js
@@ -5,7 +5,7 @@ export default function GetIndexPatternIdsFn(es, kbnIndex) {
   // didn't incorportate with the indexPattern cache to prevent id collisions.
   let cachedPromise;
 
-  var getIds = function () {
+  let getIds = function () {
     if (cachedPromise) {
       // retrun a clone of the cached response
       return cachedPromise.then(function (cachedResp) {
diff --git a/src/ui/public/index_patterns/_index_pattern.js b/src/ui/public/index_patterns/_index_pattern.js
index 5cf219dbc67d1..4a724afc8c1d1 100644
--- a/src/ui/public/index_patterns/_index_pattern.js
+++ b/src/ui/public/index_patterns/_index_pattern.js
@@ -15,23 +15,23 @@ import IndexPatternsCalculateIndicesProvider from 'ui/index_patterns/_calculate_
 import IndexPatternsPatternCacheProvider from 'ui/index_patterns/_pattern_cache';
 export default function IndexPatternFactory(Private, timefilter, Notifier, config, kbnIndex, Promise, $rootScope, safeConfirm) {
 
-  var fieldformats = Private(RegistryFieldFormatsProvider);
-  var getIds = Private(IndexPatternsGetIdsProvider);
-  var mapper = Private(IndexPatternsMapperProvider);
-  var intervals = Private(IndexPatternsIntervalsProvider);
-  var DocSource = Private(DocSourceProvider);
-  var mappingSetup = Private(UtilsMappingSetupProvider);
-  var FieldList = Private(IndexPatternsFieldListProvider);
+  let fieldformats = Private(RegistryFieldFormatsProvider);
+  let getIds = Private(IndexPatternsGetIdsProvider);
+  let mapper = Private(IndexPatternsMapperProvider);
+  let intervals = Private(IndexPatternsIntervalsProvider);
+  let DocSource = Private(DocSourceProvider);
+  let mappingSetup = Private(UtilsMappingSetupProvider);
+  let FieldList = Private(IndexPatternsFieldListProvider);
 
-  var flattenHit = Private(IndexPatternsFlattenHitProvider);
-  var calculateIndices = Private(IndexPatternsCalculateIndicesProvider);
-  var patternCache = Private(IndexPatternsPatternCacheProvider);
+  let flattenHit = Private(IndexPatternsFlattenHitProvider);
+  let calculateIndices = Private(IndexPatternsCalculateIndicesProvider);
+  let patternCache = Private(IndexPatternsPatternCacheProvider);
 
-  var type = 'index-pattern';
+  let type = 'index-pattern';
 
-  var notify = new Notifier();
+  let notify = new Notifier();
 
-  var mapping = mappingSetup.expandShorthand({
+  let mapping = mappingSetup.expandShorthand({
     title: 'string',
     timeFieldName: 'string',
     notExpandable: 'boolean',
@@ -42,8 +42,8 @@ export default function IndexPatternFactory(Private, timefilter, Notifier, confi
       _serialize: function (map) {
         if (map == null) return;
 
-        var count = 0;
-        var serialized = _.transform(map, function (flat, format, field) {
+        let count = 0;
+        let serialized = _.transform(map, function (flat, format, field) {
           if (!format) return;
           count++;
           flat[field] = format;
@@ -54,7 +54,7 @@ export default function IndexPatternFactory(Private, timefilter, Notifier, confi
       _deserialize: function (map) {
         if (map == null) return {};
         return _.mapValues(angular.fromJson(map), function (mapping) {
-          var FieldFormat = fieldformats.byId[mapping.id];
+          let FieldFormat = fieldformats.byId[mapping.id];
           return FieldFormat && new FieldFormat(mapping.params);
         });
       }
@@ -62,11 +62,11 @@ export default function IndexPatternFactory(Private, timefilter, Notifier, confi
   });
 
   function IndexPattern(id) {
-    var self = this;
+    let self = this;
 
     setId(id);
 
-    var docSource = new DocSource();
+    let docSource = new DocSource();
 
     self.init = function () {
       // tell the docSource where to find the doc
@@ -134,7 +134,7 @@ export default function IndexPatternFactory(Private, timefilter, Notifier, confi
     self.addScriptedField = function (name, script, type, lang) {
       type = type || 'string';
 
-      var scriptFields = _.pluck(self.getScriptedFields(), 'name');
+      let scriptFields = _.pluck(self.getScriptedFields(), 'name');
 
       if (_.contains(scriptFields, name)) {
         throw new errors.DuplicateField(name);
@@ -152,7 +152,7 @@ export default function IndexPatternFactory(Private, timefilter, Notifier, confi
     };
 
     self.removeScriptedField = function (name) {
-      var fieldIndex = _.findIndex(self.fields, {
+      let fieldIndex = _.findIndex(self.fields, {
         name: name,
         scripted: true
       });
@@ -165,10 +165,10 @@ export default function IndexPatternFactory(Private, timefilter, Notifier, confi
     self.popularizeField = function (fieldName, unit) {
       if (unit == null) unit = 1;
 
-      var field = _.get(self, ['fields', 'byName', fieldName]);
+      let field = _.get(self, ['fields', 'byName', fieldName]);
       if (!field) return;
 
-      var count = Math.max((field.count || 0) + unit, 0);
+      let count = Math.max((field.count || 0) + unit, 0);
       if (field.count !== count) {
         field.count = count;
         self.save();
@@ -200,7 +200,7 @@ export default function IndexPatternFactory(Private, timefilter, Notifier, confi
     };
 
     self.toDetailedIndexList = Promise.method(function (start, stop, sortDirection) {
-      var interval = self.getInterval();
+      let interval = self.getInterval();
 
       if (interval) {
         return intervals.toIndexList(self.id, interval, start, stop, sortDirection);
@@ -230,7 +230,7 @@ export default function IndexPatternFactory(Private, timefilter, Notifier, confi
     };
 
     self.prepBody = function () {
-      var body = {};
+      let body = {};
 
       // serialize json fields
       _.forOwn(mapping, function (fieldMapping, fieldName) {
@@ -254,12 +254,12 @@ export default function IndexPatternFactory(Private, timefilter, Notifier, confi
     }
 
     self.create = function () {
-      var body = self.prepBody();
+      let body = self.prepBody();
       return docSource.doCreate(body)
       .then(setId)
       .catch(function (err) {
         if (_.get(err, 'origError.status') === 409) {
-          var confirmMessage = 'Are you sure you want to overwrite this?';
+          let confirmMessage = 'Are you sure you want to overwrite this?';
 
           return safeConfirm(confirmMessage).then(
             function () {
@@ -280,7 +280,7 @@ export default function IndexPatternFactory(Private, timefilter, Notifier, confi
     };
 
     self.save = function () {
-      var body = self.prepBody();
+      let body = self.prepBody();
       return docSource.doIndex(body).then(setId);
     };
 
diff --git a/src/ui/public/index_patterns/_intervals.js b/src/ui/public/index_patterns/_intervals.js
index a58a4dccb2668..89617306db719 100644
--- a/src/ui/public/index_patterns/_intervals.js
+++ b/src/ui/public/index_patterns/_intervals.js
@@ -3,7 +3,7 @@ import moment from 'moment';
 import IndexedArray from 'ui/indexed_array';
 export default function IndexNameIntervalsService(timefilter) {
 
-  var intervals = new IndexedArray({
+  let intervals = new IndexedArray({
     index: ['name'],
     initialSet: [
       {
@@ -40,10 +40,10 @@ export default function IndexNameIntervalsService(timefilter) {
     // setup the range that the list will span, return two moment objects that
     // are in proper order. a and b can be numbers to specify to go before or after now (respectively)
     // a certain number of times, based on the interval
-    var range = [[a, 'min', 'startOf'], [b, 'max', 'startOf']].map(function (v) {
-      var val = v[0];
-      var bound = v[1];
-      var extend = v[2];
+    let range = [[a, 'min', 'startOf'], [b, 'max', 'startOf']].map(function (v) {
+      let val = v[0];
+      let bound = v[1];
+      let extend = v[2];
 
       // grab a bound from the time filter
       if (val == null) {
@@ -64,12 +64,12 @@ export default function IndexNameIntervalsService(timefilter) {
       if (!interval) throw new Error('Interval must be one of ' + _.pluck(intervals, 'name'));
     }
 
-    var indexList = [];
-    var start = range.shift();
+    let indexList = [];
+    let start = range.shift();
     // turn stop into milliseconds to that it's not constantly converted by the while condition
-    var stop = range.shift().valueOf();
+    let stop = range.shift().valueOf();
 
-    var add = sortDirection === 'desc' ? 'unshift' : 'push';
+    let add = sortDirection === 'desc' ? 'unshift' : 'push';
 
     while (start <= stop) {
       const index = start.format(format);
diff --git a/src/ui/public/index_patterns/_local_cache.js b/src/ui/public/index_patterns/_local_cache.js
index b00a34aeb17dc..64ec26847600a 100644
--- a/src/ui/public/index_patterns/_local_cache.js
+++ b/src/ui/public/index_patterns/_local_cache.js
@@ -4,17 +4,17 @@ import angular from 'angular';
 export default function LocalCacheFactory() {
   function LocalCache(opts) {
     opts = opts || {};
-    var _id = opts.id || function (o) { return '' + o; };
-    var _cache = {};
+    let _id = opts.id || function (o) { return '' + o; };
+    let _cache = {};
 
     this.get = function (obj) {
-      var id = _id(obj);
+      let id = _id(obj);
       return _cache[id] ? JSON.parse(_cache[id]) : null;
     };
 
     this.set = function (obj, val) {
-      var id = _id(obj);
-      var clean = !_cache.hasOwnProperty(id);
+      let id = _id(obj);
+      let clean = !_cache.hasOwnProperty(id);
       _cache[id] = angular.toJson(val);
       return clean;
     };
@@ -25,7 +25,7 @@ export default function LocalCacheFactory() {
         return;
       }
 
-      var id = _id(obj);
+      let id = _id(obj);
       delete _cache[id];
     };
   }
diff --git a/src/ui/public/index_patterns/_map_field.js b/src/ui/public/index_patterns/_map_field.js
index 9bcb59aeff118..b4d3a4aa42f78 100644
--- a/src/ui/public/index_patterns/_map_field.js
+++ b/src/ui/public/index_patterns/_map_field.js
@@ -1,7 +1,7 @@
 import _ from 'lodash';
 import IndexPatternsCastMappingTypeProvider from 'ui/index_patterns/_cast_mapping_type';
 export default function MapFieldFn(Private, config) {
-  var castMappingType = Private(IndexPatternsCastMappingTypeProvider);
+  let castMappingType = Private(IndexPatternsCastMappingTypeProvider);
 
   /**
    * Accepts a field object and its name, and tries to give it a mapping
@@ -10,11 +10,11 @@ export default function MapFieldFn(Private, config) {
    * @return {Object} - the resulting field after overrides and tweaking
    */
   return function mapField(field, name) {
-    var keys = Object.keys(field.mapping);
+    let keys = Object.keys(field.mapping);
     if (keys.length === 0 || (name[0] === '_') && !_.contains(config.get('metaFields'), name)) return;
 
     // Override the mapping, even if elasticsearch says otherwise
-    var mappingOverrides = {
+    let mappingOverrides = {
       _source: { type: '_source' },
       _index: { type: 'string' },
       _type: { type: 'string' },
@@ -29,7 +29,7 @@ export default function MapFieldFn(Private, config) {
       }
     };
 
-    var mapping = _.cloneDeep(field.mapping[keys.shift()]);
+    let mapping = _.cloneDeep(field.mapping[keys.shift()]);
 
     if (!mapping.index || mapping.index === 'no') {
       // elasticsearch responds with false sometimes and 'no' others
diff --git a/src/ui/public/index_patterns/_mapper.js b/src/ui/public/index_patterns/_mapper.js
index 16bdce7d4958b..0ee8984327749 100644
--- a/src/ui/public/index_patterns/_mapper.js
+++ b/src/ui/public/index_patterns/_mapper.js
@@ -7,19 +7,19 @@ import IndexPatternsPatternToWildcardProvider from 'ui/index_patterns/_pattern_t
 import IndexPatternsLocalCacheProvider from 'ui/index_patterns/_local_cache';
 export default function MapperService(Private, Promise, es, config, kbnIndex) {
 
-  var transformMappingIntoFields = Private(IndexPatternsTransformMappingIntoFieldsProvider);
-  var intervals = Private(IndexPatternsIntervalsProvider);
-  var patternToWildcard = Private(IndexPatternsPatternToWildcardProvider);
+  let transformMappingIntoFields = Private(IndexPatternsTransformMappingIntoFieldsProvider);
+  let intervals = Private(IndexPatternsIntervalsProvider);
+  let patternToWildcard = Private(IndexPatternsPatternToWildcardProvider);
 
-  var LocalCache = Private(IndexPatternsLocalCacheProvider);
+  let LocalCache = Private(IndexPatternsLocalCacheProvider);
 
   function Mapper() {
 
     // Save a reference to mapper
-    var self = this;
+    let self = this;
 
     // proper-ish cache, keeps a clean copy of the object, only returns copies of it's copy
-    var fieldCache = self.cache = new LocalCache();
+    let fieldCache = self.cache = new LocalCache();
 
     /**
      * Gets an object containing all fields with their mappings
@@ -29,9 +29,9 @@ export default function MapperService(Private, Promise, es, config, kbnIndex) {
      * @async
      */
     self.getFieldsForIndexPattern = function (indexPattern, skipIndexPatternCache) {
-      var id = indexPattern.id;
+      let id = indexPattern.id;
 
-      var cache = fieldCache.get(id);
+      let cache = fieldCache.get(id);
       if (cache) return Promise.resolve(cache);
 
       if (!skipIndexPatternCache) {
@@ -49,7 +49,7 @@ export default function MapperService(Private, Promise, es, config, kbnIndex) {
         });
       }
 
-      var promise = Promise.resolve(id);
+      let promise = Promise.resolve(id);
       if (indexPattern.intervalName) {
         promise = self.getIndicesForIndexPattern(indexPattern)
         .then(function (existing) {
@@ -80,8 +80,8 @@ export default function MapperService(Private, Promise, es, config, kbnIndex) {
         index: patternToWildcard(indexPattern.id)
       })
       .then(function (resp) {
-        // var all = Object.keys(resp).sort();
-        var all = _(resp)
+        // let all = Object.keys(resp).sort();
+        let all = _(resp)
         .map(function (index, key) {
           if (index.aliases) {
             return [Object.keys(index.aliases), key];
@@ -94,8 +94,8 @@ export default function MapperService(Private, Promise, es, config, kbnIndex) {
         .uniq(true)
         .value();
 
-        var matches = all.filter(function (existingIndex) {
-          var parsed = moment(existingIndex, indexPattern.id);
+        let matches = all.filter(function (existingIndex) {
+          let parsed = moment(existingIndex, indexPattern.id);
           return existingIndex === parsed.format(indexPattern.id);
         });
 
diff --git a/src/ui/public/index_patterns/_pattern_cache.js b/src/ui/public/index_patterns/_pattern_cache.js
index 5b6e205e316c3..e9f57f5188e0a 100644
--- a/src/ui/public/index_patterns/_pattern_cache.js
+++ b/src/ui/public/index_patterns/_pattern_cache.js
@@ -1,9 +1,9 @@
 import _ from 'lodash';
 export default function PatternCache() {
 
-  var vals = {};
+  let vals = {};
 
-  var validId = function (id) {
+  let validId = function (id) {
     return typeof id !== 'object';
   };
 
diff --git a/src/ui/public/index_patterns/_pattern_to_wildcard.js b/src/ui/public/index_patterns/_pattern_to_wildcard.js
index e9029fb78343c..447af376c807d 100644
--- a/src/ui/public/index_patterns/_pattern_to_wildcard.js
+++ b/src/ui/public/index_patterns/_pattern_to_wildcard.js
@@ -1,11 +1,11 @@
 export default function PatternToWildcardFn() {
   return function (format) {
-    var wildcard = '';
-    var inEscape = false;
-    var inPattern = false;
+    let wildcard = '';
+    let inEscape = false;
+    let inPattern = false;
 
-    for (var i = 0; i < format.length; i++) {
-      var ch = format.charAt(i);
+    for (let i = 0; i < format.length; i++) {
+      let ch = format.charAt(i);
       switch (ch) {
         case '[':
           inPattern = false;
diff --git a/src/ui/public/index_patterns/_transform_mapping_into_fields.js b/src/ui/public/index_patterns/_transform_mapping_into_fields.js
index 17c175bd348c6..059101e76695e 100644
--- a/src/ui/public/index_patterns/_transform_mapping_into_fields.js
+++ b/src/ui/public/index_patterns/_transform_mapping_into_fields.js
@@ -1,7 +1,7 @@
 import _ from 'lodash';
 import IndexPatternsMapFieldProvider from 'ui/index_patterns/_map_field';
 export default function transformMappingIntoFields(Private, kbnIndex, config) {
-  var mapField = Private(IndexPatternsMapFieldProvider);
+  let mapField = Private(IndexPatternsMapFieldProvider);
 
 
   /**
@@ -14,15 +14,15 @@ export default function transformMappingIntoFields(Private, kbnIndex, config) {
    *                    use-cases
    */
   return function (response) {
-    var fields = {};
+    let fields = {};
     _.each(response, function (index, indexName) {
       if (indexName === kbnIndex) return;
       _.each(index.mappings, function (mappings) {
         _.each(mappings, function (field, name) {
-          var keys = Object.keys(field.mapping);
+          let keys = Object.keys(field.mapping);
           if (keys.length === 0 || (name[0] === '_') && !_.contains(config.get('metaFields'), name)) return;
 
-          var mapping = mapField(field, name);
+          let mapping = mapField(field, name);
 
           if (fields[name]) {
             if (fields[name].type !== mapping.type) {
@@ -39,7 +39,7 @@ export default function transformMappingIntoFields(Private, kbnIndex, config) {
     config.get('metaFields').forEach(function (meta) {
       if (fields[meta]) return;
 
-      var field = { mapping: {} };
+      let field = { mapping: {} };
       field.mapping[meta] = {};
       fields[meta] = mapField(field, meta);
     });
diff --git a/src/ui/public/index_patterns/index_patterns.js b/src/ui/public/index_patterns/index_patterns.js
index 7d8e709d03b10..18ea1b7c95cfd 100644
--- a/src/ui/public/index_patterns/index_patterns.js
+++ b/src/ui/public/index_patterns/index_patterns.js
@@ -9,20 +9,20 @@ import IndexPatternsMapperProvider from 'ui/index_patterns/_mapper';
 import IndexPatternsPatternToWildcardProvider from 'ui/index_patterns/_pattern_to_wildcard';
 import RegistryFieldFormatsProvider from 'ui/registry/field_formats';
 import uiModules from 'ui/modules';
-var module = uiModules.get('kibana/index_patterns');
+let module = uiModules.get('kibana/index_patterns');
 
 function IndexPatternsProvider(es, Notifier, Private, Promise, kbnIndex) {
-  var self = this;
+  let self = this;
 
-  var IndexPattern = Private(IndexPatternsIndexPatternProvider);
-  var patternCache = Private(IndexPatternsPatternCacheProvider);
+  let IndexPattern = Private(IndexPatternsIndexPatternProvider);
+  let patternCache = Private(IndexPatternsPatternCacheProvider);
 
-  var notify = new Notifier({ location: 'IndexPatterns Service'});
+  let notify = new Notifier({ location: 'IndexPatterns Service'});
 
   self.get = function (id) {
     if (!id) return self.make();
 
-    var cache = patternCache.get(id);
+    let cache = patternCache.get(id);
     return cache || patternCache.set(id, self.make(id));
   };
 
diff --git a/src/ui/public/indexed_array/indexed_array.js b/src/ui/public/indexed_array/indexed_array.js
index aa042fd3312fc..3c7f81fcb52db 100644
--- a/src/ui/public/indexed_array/indexed_array.js
+++ b/src/ui/public/indexed_array/indexed_array.js
@@ -2,12 +2,12 @@ import _ from 'lodash';
 import inflector from 'ui/indexed_array/inflector';
 
 
-var pathGetter = _(_.get).rearg(1, 0).ary(2);
-var inflectIndex = inflector('by');
-var inflectOrder = inflector('in', 'Order');
+let pathGetter = _(_.get).rearg(1, 0).ary(2);
+let inflectIndex = inflector('by');
+let inflectOrder = inflector('in', 'Order');
 
-var CLEAR_CACHE = {};
-var OPT_NAMES = IndexedArray.OPT_NAMES = ['index', 'group', 'order', 'initialSet', 'immutable'];
+let CLEAR_CACHE = {};
+let OPT_NAMES = IndexedArray.OPT_NAMES = ['index', 'group', 'order', 'initialSet', 'immutable'];
 
 /**
  * Generic extension of Array class, which will index (and reindex) the
@@ -69,11 +69,11 @@ IndexedArray.prototype._setupIndices = function (props, inflect, op) {
   // shortcut for empty props
   if (!props || props.length === 0) return;
 
-  var self = this;
+  let self = this;
   return props.map(function (prop) {
 
-    var from = pathGetter.partial(prop).value();
-    var to = inflect(prop);
+    let from = pathGetter.partial(prop).value();
+    let to = inflect(prop);
     let cache;
 
     Object.defineProperty(self, to, {
@@ -105,7 +105,7 @@ IndexedArray.prototype._setupIndices = function (props, inflect, op) {
  * @return {undefined}
  */
 IndexedArray.prototype._clearIndices = function () {
-  var self = this;
+  let self = this;
   self._indexNames.forEach(function (name) {
     self[name] = CLEAR_CACHE;
   });
@@ -120,7 +120,7 @@ IndexedArray.prototype._clearIndices = function () {
  * @return {[type]}        [description]
  */
 'pop push shift splice unshift reverse'.split(' ').forEach(function (method) {
-  var orig = Array.prototype[method];
+  let orig = Array.prototype[method];
 
   IndexedArray.prototype[method] = function (/* args... */) {
     // call the original method with this context
@@ -141,7 +141,7 @@ IndexedArray.prototype._clearIndices = function () {
 * @return {array} - the removed data
 */
 IndexedArray.prototype.remove = function (predicate, context) {
-  var out = _.remove(this, predicate, context);
+  let out = _.remove(this, predicate, context);
   _.remove(this.raw, predicate, context);
   this._clearIndices();
   return out;
diff --git a/src/ui/public/indexed_array/inflector.js b/src/ui/public/indexed_array/inflector.js
index 17cebbbc6d1b5..f879cbdf8965e 100644
--- a/src/ui/public/indexed_array/inflector.js
+++ b/src/ui/public/indexed_array/inflector.js
@@ -8,7 +8,7 @@ function startsWith(str, test) {
 }
 
 function endsWith(str, test) {
-  var tooShort = str.length < test.length;
+  let tooShort = str.length < test.length;
   if (tooShort) return;
 
   return str.substr(str.length - test.length).toLowerCase() === test.toLowerCase();
diff --git a/src/ui/public/jquery/find_test_subject.js b/src/ui/public/jquery/find_test_subject.js
index cc1e6e10a9e7d..935bb67a14558 100644
--- a/src/ui/public/jquery/find_test_subject.js
+++ b/src/ui/public/jquery/find_test_subject.js
@@ -7,28 +7,28 @@ module.exports = function bindToJquery($) {
    *
    * ```js
    * // this
-   * var $button = $('[data-test-subj~="saveButton"]');
+   * let $button = $('[data-test-subj~="saveButton"]');
    *
    * // becomes this
-   * var $button = $.findTestSubject('saveButton');
+   * let $button = $.findTestSubject('saveButton');
    * ```
    *
    * Supports multiple subjects
    * ```js
    * // find any saveButton or cancelButton
-   * var $buttons = $.findTestSubject('saveButton', 'cancelButton');
+   * let $buttons = $.findTestSubject('saveButton', 'cancelButton');
    * ```
    *
    * Supports subject "selectors"
    * ```js
    * // find any saveButton inside a savedObjectForm
-   * var $button = $.findTestSubject('savedObjectForm saveButton');
+   * let $button = $.findTestSubject('savedObjectForm saveButton');
    * ```
    *
    * Supports selecting compound subjects
    * ```js
    * // find any smallButton that is also a saveButton inside a savedObjectForm
-   * var $input = $.findTestSubject('savedObjectForm smallButton&saveButton');
+   * let $input = $.findTestSubject('savedObjectForm smallButton&saveButton');
    * ```
    *
    * @return {jQueryCollection}
@@ -44,8 +44,8 @@ module.exports = function bindToJquery($) {
   $.fn.findTestSubject = findTestSubject;
 
   function findTestSubject(...subjectSelectors) {
-    var $els = $();
-    var $context = this;
+    let $els = $();
+    let $context = this;
 
     subjectSelectors.forEach(function (selector) {
       $els = $els.add($context.find(testSubjSelector(selector)));
diff --git a/src/ui/public/notify/directives.js b/src/ui/public/notify/directives.js
index 8582b0bf81712..b6d97e5a3d03d 100644
--- a/src/ui/public/notify/directives.js
+++ b/src/ui/public/notify/directives.js
@@ -3,7 +3,7 @@ import uiModules from 'ui/modules';
 import toasterTemplate from 'ui/notify/partials/toaster.html';
 import 'ui/notify/notify.less';
 
-var notify = uiModules.get('kibana/notify');
+let notify = uiModules.get('kibana/notify');
 
 notify.directive('kbnNotifications', function () {
   return {
diff --git a/src/ui/public/notify/errors.js b/src/ui/public/notify/errors.js
index fb74b7450be3e..68a040466124f 100644
--- a/src/ui/public/notify/errors.js
+++ b/src/ui/public/notify/errors.js
@@ -1,8 +1,8 @@
 import _ from 'lodash';
-var errors = {};
+let errors = {};
 
-var canStack = (function () {
-  var err = new Error();
+let canStack = (function () {
+  let err = new Error();
   return !!err.stack;
 }());
 
diff --git a/src/ui/public/notify/lib/_format_es_msg.js b/src/ui/public/notify/lib/_format_es_msg.js
index 1148da4064765..ac8c6b043a625 100644
--- a/src/ui/public/notify/lib/_format_es_msg.js
+++ b/src/ui/public/notify/lib/_format_es_msg.js
@@ -6,11 +6,11 @@ import _ from 'lodash';
  * @returns {string}
  */
 export default function formatESMsg(err) {
-  var rootCause = _.get(err, 'resp.error.root_cause');
+  let rootCause = _.get(err, 'resp.error.root_cause');
   if (!rootCause) {
     return; //undefined
   }
 
-  var result = _.pluck(rootCause, 'reason').join('\n');
+  let result = _.pluck(rootCause, 'reason').join('\n');
   return result;
 };
diff --git a/src/ui/public/notify/lib/_format_msg.js b/src/ui/public/notify/lib/_format_msg.js
index 15f0260c5b7df..448c4fa4b2c8c 100644
--- a/src/ui/public/notify/lib/_format_msg.js
+++ b/src/ui/public/notify/lib/_format_msg.js
@@ -1,6 +1,6 @@
 import _ from 'lodash';
 import formatESMsg from 'ui/notify/lib/_format_es_msg';
-var has = _.has;
+let has = _.has;
 
 /**
  * Formats the error message from an error object, extended elasticsearch
@@ -10,12 +10,12 @@ var has = _.has;
  * @returns {string}
  */
 function formatMsg(err, from) {
-  var rtn = '';
+  let rtn = '';
   if (from) {
     rtn += from + ': ';
   }
 
-  var esMsg = formatESMsg(err);
+  let esMsg = formatESMsg(err);
 
   if (typeof err === 'string') {
     rtn += err;
diff --git a/src/ui/public/notify/notifier.js b/src/ui/public/notify/notifier.js
index e72740d189455..a498f4ebbff09 100644
--- a/src/ui/public/notify/notifier.js
+++ b/src/ui/public/notify/notifier.js
@@ -5,17 +5,17 @@ import formatMsg from 'ui/notify/lib/_format_msg';
 import fatalSplashScreen from 'ui/notify/partials/fatal_splash_screen.html';
 /* eslint no-console: 0 */
 
-var notifs = [];
-var version = metadata.version;
-var buildNum = metadata.buildNum;
-var consoleGroups = ('group' in window.console) && ('groupCollapsed' in window.console) && ('groupEnd' in window.console);
+let notifs = [];
+let version = metadata.version;
+let buildNum = metadata.buildNum;
+let consoleGroups = ('group' in window.console) && ('groupCollapsed' in window.console) && ('groupEnd' in window.console);
 
-var log = _.bindKey(console, 'log');
+let log = _.bindKey(console, 'log');
 
 // used to identify the first call to fatal, set to false there
-var firstFatal = true;
+let firstFatal = true;
 
-var fatalToastTemplate = (function lazyTemplate(tmpl) {
+let fatalToastTemplate = (function lazyTemplate(tmpl) {
   let compiled;
   return function (vars) {
     return (compiled || (compiled = _.template(tmpl)))(vars);
@@ -32,7 +32,7 @@ function now() {
 function closeNotif(notif, cb = _.noop, key) {
   return function () {
     // this === notif
-    var i = notifs.indexOf(notif);
+    let i = notifs.indexOf(notif);
     if (i !== -1) notifs.splice(i, 1);
 
     cancelTimer(notif);
@@ -59,7 +59,7 @@ function timerCanceler(notif, cb = _.noop, key) {
  * intervals and clears the notif once the notif _lifetime_ has been reached.
  */
 function startNotifTimer(notif, cb) {
-  var interval = 1000;
+  let interval = 1000;
 
   if (notif.lifetime === Infinity) return;
 
@@ -99,7 +99,7 @@ function add(notif, cb) {
     return notif.timerId ? true : false;
   };
 
-  var dup = _.find(notifs, function (item) {
+  let dup = _.find(notifs, function (item) {
     return item.content === notif.content && item.lifetime === notif.lifetime;
   });
 
@@ -120,7 +120,7 @@ function add(notif, cb) {
 }
 
 function formatInfo() {
-  var info = [];
+  let info = [];
 
   if (!_.isUndefined(version)) {
     info.push(`Version: ${version}`);
@@ -145,7 +145,7 @@ function formatStack(err) {
  * Functionality to check that
  */
 function Notifier(opts) {
-  var self = this;
+  let self = this;
   opts = opts || {};
 
   // label type thing to say where notifications came from
@@ -200,7 +200,7 @@ Notifier.prototype.lifecycle = createGroupLogger('lifecycle', {
  * @return {function} - the wrapped function
  */
 Notifier.prototype.timed = function (name, fn) {
-  var self = this;
+  let self = this;
 
   if (typeof name === 'function') {
     fn = name;
@@ -208,8 +208,8 @@ Notifier.prototype.timed = function (name, fn) {
   }
 
   return function WrappedNotifierFunction() {
-    var cntx = this;
-    var args = arguments;
+    let cntx = this;
+    let args = arguments;
 
     return self.event(name, function () {
       return fn.apply(cntx, args);
@@ -245,13 +245,13 @@ Notifier.prototype._showFatal = function (err) {
     });
   }
 
-  var html = fatalToastTemplate({
+  let html = fatalToastTemplate({
     info: formatInfo(),
     msg: formatMsg(err, this.from),
     stack: formatStack(err)
   });
 
-  var $container = $('#fatal-splash-screen');
+  let $container = $('#fatal-splash-screen');
 
   if (!$container.size()) {
     $(document.body)
@@ -320,7 +320,7 @@ if (log === _.noop) {
   Notifier.prototype.log = _.noop;
 } else {
   Notifier.prototype.log = function () {
-    var args = [].slice.apply(arguments);
+    let args = [].slice.apply(arguments);
     if (this.from) args.unshift(this.from + ':');
     log.apply(null, args);
   };
@@ -329,15 +329,15 @@ if (log === _.noop) {
 // general functionality used by .event() and .lifecycle()
 function createGroupLogger(type, opts) {
   // Track the groups managed by this logger
-  var groups = window[type + 'Groups'] = {};
+  let groups = window[type + 'Groups'] = {};
 
   return function logger(name, success) {
     let status; // status of the timer
     let exec; // function to execute and wrap
     let ret; // return value
 
-    var complete = function (val) { logger(name, true); return val; };
-    var failure = function (err) { logger(name, false); throw err; };
+    let complete = function (val) { logger(name, true); return val; };
+    let failure = function (err) { logger(name, false); throw err; };
 
     if (typeof success === 'function' || success === void 0) {
       // start
@@ -353,7 +353,7 @@ function createGroupLogger(type, opts) {
     }
     else {
       groups[name] = now() - (groups[name] || 0);
-      var time = ' in ' + groups[name].toFixed(2) + 'ms';
+      let time = ' in ' + groups[name].toFixed(2) + 'ms';
 
       // end
       if (success) {
diff --git a/src/ui/public/notify/notify.js b/src/ui/public/notify/notify.js
index b26eecd8ba7e8..159cac233946d 100644
--- a/src/ui/public/notify/notify.js
+++ b/src/ui/public/notify/notify.js
@@ -6,8 +6,8 @@ import Notifier from 'ui/notify/notifier';
 import 'ui/notify/directives';
 import chrome from 'ui/chrome';
 import { kbnIndex } from 'ui/metadata';
-var module = modules.get('kibana/notify');
-var rootNotifier = new Notifier();
+let module = modules.get('kibana/notify');
+let rootNotifier = new Notifier();
 
 module.factory('createNotifier', function () {
   return function (opts) {
@@ -32,7 +32,7 @@ module.run(function ($interval) {
 if (!!kbnIndex) {
   require('ui/config');
   module.run(function ($rootScope, config) {
-    var configInitListener = $rootScope.$on('init:config', function () {
+    let configInitListener = $rootScope.$on('init:config', function () {
       applyConfig();
       configInitListener();
     });
diff --git a/src/ui/public/number_list/number_list.js b/src/ui/public/number_list/number_list.js
index 1528dea37cfe7..9c18da1f3058f 100644
--- a/src/ui/public/number_list/number_list.js
+++ b/src/ui/public/number_list/number_list.js
@@ -13,7 +13,7 @@ uiModules
     controllerAs: 'numberListCntr',
     require: 'ngModel',
     controller: function ($scope, $attrs, $parse) {
-      var self = this;
+      let self = this;
 
       // Called from the pre-link function once we have the controllers
       self.init = function (modelCntr) {
@@ -25,7 +25,7 @@ uiModules
 
         self.getUnitName = _.partial($parse($attrs.unit), $scope);
 
-        var defaultRange = self.range = parseRange('[0,Infinity)');
+        let defaultRange = self.range = parseRange('[0,Infinity)');
 
         $scope.$watch(function () {
           return $attrs.range;
@@ -48,7 +48,7 @@ uiModules
          * @return {undefined}
          */
         self.remove = function (index) {
-          var list = self.getList();
+          let list = self.getList();
           if (!list) return;
 
           list.splice(index, 1);
@@ -59,7 +59,7 @@ uiModules
          * @return {undefined}
          */
         self.add = function () {
-          var list = self.getList();
+          let list = self.getList();
           if (!list) return;
 
           list.push(_.last(list) + 1);
diff --git a/src/ui/public/number_list/number_list_input.js b/src/ui/public/number_list/number_list_input.js
index de0b47350c8f9..7fbf1b935e02f 100644
--- a/src/ui/public/number_list/number_list_input.js
+++ b/src/ui/public/number_list/number_list_input.js
@@ -3,11 +3,11 @@ import _ from 'lodash';
 import keyMap from 'ui/utils/key_map';
 import uiModules from 'ui/modules';
 
-var INVALID = {}; // invalid flag
-var FLOATABLE = /^[\d\.e\-\+]+$/i;
+let INVALID = {}; // invalid flag
+let FLOATABLE = /^[\d\.e\-\+]+$/i;
 
-var VALIDATION_ERROR = 'numberListRangeAndOrder';
-var DIRECTIVE_ATTR = 'kbn-number-list-input';
+let VALIDATION_ERROR = 'numberListRangeAndOrder';
+let DIRECTIVE_ATTR = 'kbn-number-list-input';
 
 uiModules
 .get('kibana')
@@ -16,13 +16,13 @@ uiModules
     restrict: 'A',
     require: ['ngModel', '^kbnNumberList'],
     link: function ($scope, $el, attrs, controllers) {
-      var ngModelCntr = controllers[0];
-      var numberListCntr = controllers[1];
+      let ngModelCntr = controllers[0];
+      let numberListCntr = controllers[1];
 
-      var $setModel = $parse(attrs.ngModel).assign;
-      var $repeater = $el.closest('[ng-repeat]');
+      let $setModel = $parse(attrs.ngModel).assign;
+      let $repeater = $el.closest('[ng-repeat]');
 
-      var handlers = {
+      let handlers = {
         up: change(add, 1),
         'shift-up': change(addTenth, 1),
 
@@ -54,14 +54,14 @@ uiModules
 
       function go(dir) {
         return function () {
-          var $to = $get(dir);
+          let $to = $get(dir);
           if ($to.size()) $to.focus();
           else return false;
         };
       }
 
       function idKey(event) {
-        var id = [];
+        let id = [];
         if (event.ctrlKey) id.push('ctrl');
         if (event.shiftKey) id.push('shift');
         if (event.metaKey) id.push('meta');
@@ -75,8 +75,8 @@ uiModules
       }
 
       function addTenth(n, val, str) {
-        var int = Math.floor(val);
-        var dec = parseInt(str.split('.')[1] || 0, 10);
+        let int = Math.floor(val);
+        let dec = parseInt(str.split('.')[1] || 0, 10);
         dec = dec + parseInt(n, 10);
 
         if (dec < 0 || dec > 9) {
@@ -93,11 +93,11 @@ uiModules
 
       function change(using, mod) {
         return function () {
-          var str = String(ngModelCntr.$viewValue);
-          var val = parse(str);
+          let str = String(ngModelCntr.$viewValue);
+          let val = parse(str);
           if (val === INVALID) return;
 
-          var next = using(mod, val, str);
+          let next = using(mod, val, str);
           if (next === INVALID) return;
 
           $el.val(next);
@@ -106,7 +106,7 @@ uiModules
       }
 
       function onKeydown(event) {
-        var handler = handlers[idKey(event)];
+        let handler = handlers[idKey(event)];
         if (!handler) return;
 
         if (handler(event) !== false) {
@@ -122,7 +122,7 @@ uiModules
       });
 
       function parse(viewValue) {
-        var num = viewValue;
+        let num = viewValue;
 
         if (typeof num !== 'number' || isNaN(num)) {
           // parse non-numbers
@@ -133,13 +133,13 @@ uiModules
           if (isNaN(num)) return INVALID;
         }
 
-        var range = numberListCntr.range;
+        let range = numberListCntr.range;
         if (!range.within(num)) return INVALID;
 
         if ($scope.$index > 0) {
-          var i = $scope.$index - 1;
-          var list = numberListCntr.getList();
-          var prev = list[i];
+          let i = $scope.$index - 1;
+          let list = numberListCntr.getList();
+          let prev = list[i];
           if (num <= prev) return INVALID;
         }
 
@@ -155,14 +155,14 @@ uiModules
           }
         }
       ], function () {
-        var valid = parse(ngModelCntr.$viewValue) !== INVALID;
+        let valid = parse(ngModelCntr.$viewValue) !== INVALID;
         ngModelCntr.$setValidity(VALIDATION_ERROR, valid);
       });
 
       function validate(then) {
         return function (input) {
-          var value = parse(input);
-          var valid = value !== INVALID;
+          let value = parse(input);
+          let valid = value !== INVALID;
           value = valid ? value : input;
           ngModelCntr.$setValidity(VALIDATION_ERROR, valid);
           then && then(input, value);