diff --git a/js/grunt/Gruntfile.js b/js/grunt/Gruntfile.js
index 6f62e3c95..c769fa856 100644
--- a/js/grunt/Gruntfile.js
+++ b/js/grunt/Gruntfile.js
@@ -22,6 +22,7 @@ const generateTestHTML = require( './generateTestHTML' );
 const generateThumbnails = require( './generateThumbnails' );
 const generateTwitterCard = require( './generateTwitterCard' );
 const getPhetLibs = require( './getPhetLibs' );
+const format = require( './format' );
 const lint = require( './lint' );
 const fixEOL = require( './fixEOL' );
 const migrate = require( './migrate' );
@@ -275,6 +276,22 @@ module.exports = function( grunt ) {
     lint( getPhetLibs( repo ), cache );
   } ) );
 
+  grunt.registerTask( 'format', 'format js files that are specific to this repository', wrapTask( async () => {
+
+    //Don't actually modify the files, just verify them?
+    const verifyOnly = !!grunt.option( 'verify' );
+
+    format( [ repo ], verifyOnly );
+  } ) );
+
+  grunt.registerTask( 'format-all', 'format all js files that are required to build this repository (for all supported brands)', wrapTask( async () => {
+
+    //Don't actually modify the files, just verify them?
+    const verifyOnly = !!grunt.option( 'verify' );
+
+    format( getPhetLibs( repo ), verifyOnly );
+  } ) );
+
   grunt.registerTask( 'generate-development-html',
     'Generates top-level SIM_en.html file based on the preloads in package.json.',
     wrapTask( async () => {
diff --git a/js/grunt/format.js b/js/grunt/format.js
new file mode 100644
index 000000000..66190a60d
--- /dev/null
+++ b/js/grunt/format.js
@@ -0,0 +1,90 @@
+// Copyright 2020, Nick Crews
+
+/**
+ * Runs the formatting rules on the specified files.
+ *
+ * @author @NickCrews
+ */
+
+'use strict';
+
+// modules
+const beautify = require( 'js-beautify' );
+const fs = require( 'fs' );
+const grunt = require( 'grunt' );
+const sortImports = require( './sortImports' );
+
+const OPTIONS = {
+  "html": {
+    "allowed_file_extensions": [ "htm", "html", "xhtml", "shtml", "xml", "svg" ],
+    "brace_style": "collapse",
+    "end_with_newline": false,
+    "indent_char": " ",
+    "indent_handlebars": false,
+    "indent_inner_html": false,
+    "indent_size": 2,
+    "indent_scripts": "keep",
+    "max_preserve_newlines": 1,
+    "preserve_newlines": true,
+    "unformatted": [ "a", "span", "img", "code", "pre", "sub", "sup", "em", "strong", "b", "i", "u", "strike", "big", "small", "pre", "h1", "h2", "h3", "h4", "h5", "h6" ],
+    "wrap_line_length": 0
+  },
+  "css": {
+    "allowed_file_extensions": [ "css", "scss", "sass", "less" ],
+    "end_with_newline": false,
+    "newline_between_rules": true,
+    "indent_char": " ",
+    "indent_size": 2,
+    "selector_separator": " ",
+    "selector_separator_newline": true
+  },
+  "js": {
+    "allowed_file_extensions": [ "js", "json", "jshintrc", "jsbeautifyrc", "sublime-settings" ],
+    "brace_style": "collapse-preserve-inline",
+    "break_chained_methods": false,
+    "e4x": false,
+    "end_with_newline": true,
+    "indent_char": " ",
+    "indent_level": 0,
+    "indent_size": 2,
+    "indent_with_tabs": false,
+    "jslint_happy": false,
+    "keep_array_indentation": false,
+    "keep_function_indentation": false,
+    "max_preserve_newlines": 0,
+    "preserve_newlines": true,
+    "space_after_anon_function": false,
+    "space_before_conditional": true,
+    "space_in_empty_paren": false,
+    "space_in_paren": true,
+    "unescape_strings": false,
+    "wrap_line_length": 0
+  }
+}
+
+function formatFile( absPath, verifyOnly = false ) {
+  let before = fs.readFileSync( absPath, 'utf-8' );
+  const formatted = beautify.js( before, OPTIONS );
+  if ( !verifyOnly ){
+    fs.writeFileSync( absPath, formatted, 'utf-8' );
+  }
+  const alreadySorted = sortImports( absPath, verifyOnly );
+  return alreadySorted && ( before == formatted );
+}
+
+/**
+ * Formats the specified repositories.
+ * @public
+ *
+ * @param {Array.<string>} repos
+ * @param {boolean} verifyOnly - Don't rewrite files
+ */
+module.exports = function( repos, verifyOnly = false) {
+
+  repos.forEach( repo => {
+    grunt.file.recurse(
+      `../${repo}/js`,
+      absPath => formatFile( absPath, verifyOnly )
+  ) } );
+
+}
diff --git a/js/grunt/sortImports.js b/js/grunt/sortImports.js
index 0fcb43d86..cb46608cb 100644
--- a/js/grunt/sortImports.js
+++ b/js/grunt/sortImports.js
@@ -28,10 +28,12 @@ const isImport = line => line.startsWith( 'import ' );
 
 /**
  * @param {string} file
+ * @param {boolean} verifyOnly - Don't rewrite file, just verify already sorted
+ * @returns {boolean} - Was the file properly sorted to begin with?
  */
-module.exports = function( file ) {
-  let contents = fs.readFileSync( file, 'utf-8' );
-  let lines = contents.split( /\r?\n/ );
+module.exports = function( file, verifyOnly = false ) {
+  const before = fs.readFileSync( file, 'utf-8' );
+  let lines = before.split( /\r?\n/ );
 
   // remove the grouping comments
   lines = lines.filter( ( line, i ) => {
@@ -67,6 +69,9 @@ module.exports = function( file ) {
     firstImportIndex--;
   }
 
-  contents = lines.join( '\n' );
-  fs.writeFileSync( file, contents, 'utf-8' );
+  const after = lines.join( '\n' );
+  if (!verifyOnly){
+    fs.writeFileSync( file, after, 'utf-8' );
+  }
+  return (after == before);
 };
diff --git a/package.json b/package.json
index 4ef34e3bd..794596e8f 100644
--- a/package.json
+++ b/package.json
@@ -14,6 +14,7 @@
     "eslint": "^6.8.0",
     "eslint-plugin-react": "^7.18.0",
     "grunt": "~1.1.0",
+    "grunt-jsbeautifier": "^0.2.13",
     "jimp": "^0.2.0",
     "jpeg-js": "~0.1.1",
     "jscpd": "^0.6.18",