diff --git a/src/lib/Preview.js b/src/lib/Preview.js
index 93c0b522f..343df5240 100644
--- a/src/lib/Preview.js
+++ b/src/lib/Preview.js
@@ -190,7 +190,7 @@ class Preview extends EventEmitter {
      */
     destroy() {
         // Log all load metrics
-        this.emitLoadMetrics();
+        this.emitLoadMetrics({});
 
         // Destroy viewer
         if (this.viewer && typeof this.viewer.destroy === 'function') {
diff --git a/src/lib/__tests__/Preview-test.js b/src/lib/__tests__/Preview-test.js
index c7bd6b1a6..d75836e20 100644
--- a/src/lib/__tests__/Preview-test.js
+++ b/src/lib/__tests__/Preview-test.js
@@ -8,7 +8,7 @@ import PreviewError from '../PreviewError';
 import DownloadReachability from '../DownloadReachability';
 import * as file from '../file';
 import * as util from '../util';
-import { API_HOST, CLASS_NAVIGATION_VISIBILITY, PERMISSION_PREVIEW } from '../constants';
+import { API_HOST, CLASS_NAVIGATION_VISIBILITY, PERMISSION_PREVIEW, ENCODING_TYPES } from '../constants';
 import { VIEWER_EVENT, ERROR_CODE, LOAD_METRIC, PREVIEW_METRIC } from '../events';
 import Timer from '../Timer';
 
@@ -2320,7 +2320,7 @@ describe('lib/Preview', () => {
             sandbox.stub(Timer, 'reset');
             sandbox.stub(preview, 'emit');
             preview.file = undefined;
-            preview.emitLoadMetrics();
+            preview.emitLoadMetrics({});
             expect(Timer.reset).to.not.be.called;
             expect(preview.emit).to.not.be.called;
         });
@@ -2329,7 +2329,7 @@ describe('lib/Preview', () => {
             preview.once(PREVIEW_METRIC, () => {
                 done();
             });
-            preview.emitLoadMetrics();
+            preview.emitLoadMetrics({});
         });
 
         it('should emit a preview_metric event with event_name "load"', (done) => {
@@ -2337,7 +2337,7 @@ describe('lib/Preview', () => {
                 expect(metric.event_name).to.equal(LOAD_METRIC.previewLoadEvent);
                 done();
             });
-            preview.emitLoadMetrics();
+            preview.emitLoadMetrics({});
         });
 
         it('should emit a preview_metric event where the value property equals the sum of all load events', (done) => {
@@ -2354,7 +2354,7 @@ describe('lib/Preview', () => {
                 expect(metric.value).to.equal(expectedTime);
                 done();
             });
-            preview.emitLoadMetrics();
+            preview.emitLoadMetrics({});
         });
 
         it('should emit a preview_metric event with an object, with all of the proper load properties', (done) => {
@@ -2365,13 +2365,13 @@ describe('lib/Preview', () => {
                 expect(metric[LOAD_METRIC.fullDocumentLoadTime]).to.exist;
                 done();
             });
-            preview.emitLoadMetrics();
+            preview.emitLoadMetrics({});
         });
 
         it('should reset the Timer', () => {
             sandbox.stub(Timer, 'reset');
             sandbox.stub(preview, 'emit');
-            preview.emitLoadMetrics();
+            preview.emitLoadMetrics({});
             expect(Timer.reset).to.be.called;
             expect(preview.emit).to.be.called;
         });
@@ -2385,7 +2385,15 @@ describe('lib/Preview', () => {
                 expect(metric[LOAD_METRIC.fullDocumentLoadTime]).to.equal(0);
                 done();
             });
-            preview.emitLoadMetrics();
+            preview.emitLoadMetrics({});
+        });
+
+        it('should append encoding field to load metric, when provided', (done) => {
+            preview.once(PREVIEW_METRIC, (metric) => {
+                expect(metric.encoding).to.equal(ENCODING_TYPES.GZIP);
+                done();
+            });
+            preview.emitLoadMetrics({ encoding: ENCODING_TYPES.GZIP });
         });
     });
 
diff --git a/src/lib/viewers/doc/__tests__/DocBaseViewer-test.js b/src/lib/viewers/doc/__tests__/DocBaseViewer-test.js
index 9192c746f..f8d357830 100644
--- a/src/lib/viewers/doc/__tests__/DocBaseViewer-test.js
+++ b/src/lib/viewers/doc/__tests__/DocBaseViewer-test.js
@@ -1445,9 +1445,11 @@ describe('src/lib/viewers/doc/DocBaseViewer', () => {
             };
             docBase.loaded = false;
             docBase.pdfViewer.pagesCount = 5;
+            docBase.encoding = 'gzip';
 
             docBase.pagesinitHandler();
             expect(stubs.emit).to.be.calledWith(VIEWER_EVENT.load, {
+                encoding: docBase.encoding,
                 endProgress: false,
                 numPages: 5,
                 scale: sinon.match.any