diff --git a/web/viewer.html b/web/viewer.html
index 53ca2a247..869bf0f2e 100644
--- a/web/viewer.html
+++ b/web/viewer.html
@@ -67,10 +67,11 @@
         <option value="0.75">75%</option>
         <option value="1">100%</option>
         <option value="1.25">125%</option>
-        <option value="1.5" selected="selected">150%</option>
+        <option value="1.5">150%</option>
         <option value="2">200%</option>
         <option id="pageWidthOption" value="page-width">Page Width</option>
         <option id="pageFitOption" value="page-fit">Page Fit</option>
+        <option id="pageAutoOption" value="auto" selected="selected">Auto</option>
       </select>
 
       <div class="separator"></div>
diff --git a/web/viewer.js b/web/viewer.js
index b596de213..12158c4b8 100644
--- a/web/viewer.js
+++ b/web/viewer.js
@@ -4,7 +4,7 @@
 'use strict';
 
 var kDefaultURL = 'compressed.tracemonkey-pldi-09.pdf';
-var kDefaultScale = 1.5;
+var kDefaultScale = 'auto';
 var kDefaultScaleDelta = 1.1;
 var kCacheSize = 20;
 var kCssUnits = 96.0 / 72.0;
@@ -187,6 +187,11 @@ var PDFView = {
       this.setScale(
         Math.min(pageWidthScale, pageHeightScale), resetAutoSettings);
     }
+    if ('auto' == value) {
+      this.setScale(Math.min(1.0, pageWidthScale), resetAutoSettings);
+    }
+
+    selectScaleOption(value);
   },
 
   zoomIn: function pdfViewZoomIn() {
@@ -1000,7 +1005,8 @@ window.addEventListener('webkitTransitionEnd', updateThumbViewArea, true);
 
 window.addEventListener('resize', function webViewerResize(evt) {
   if (document.getElementById('pageWidthOption').selected ||
-      document.getElementById('pageFitOption').selected)
+      document.getElementById('pageFitOption').selected ||
+      document.getElementById('pageAutoOption').selected)
       PDFView.parseScale(document.getElementById('scaleSelect').value);
   updateViewarea();
 });