diff --git a/browser/base/content/browser-thumbnails.js b/browser/base/content/browser-thumbnails.js
--- a/browser/base/content/browser-thumbnails.js
+++ b/browser/base/content/browser-thumbnails.js
@@ -104,21 +104,16 @@ var gBrowserThumbnails = {
         this._activityStreamEnabled =
           Services.prefs.getBoolPref(this.PREF_ACTIVITY_STREAM_ENABLED);
         // Get the new top sites
         XPCOMUtils.defineLazyGetter(this, "_topSiteURLs", getTopSiteURLs);
         break;
     }
   },

-  /**
-   * clearTopSiteURLCache is only ever called if we've created an nsITimer,
-   * which only happens if we've loaded the tiles top sites. Therefore we only
-   * need to clear the tiles top sites (and not activity stream's top sites)
-   */
   clearTopSiteURLCache: function Thumbnails_clearTopSiteURLCache() {
     if (this._topSiteURLsRefreshTimer) {
       this._topSiteURLsRefreshTimer.cancel();
       this._topSiteURLsRefreshTimer = null;
     }
     // Delete the defined property
     delete this._topSiteURLs;
     XPCOMUtils.defineLazyGetter(this, "_topSiteURLs", getTopSiteURLs);
@@ -142,19 +137,29 @@ var gBrowserThumbnails = {
     if (aStateFlags & Ci.nsIWebProgressListener.STATE_STOP &&
         aStateFlags & Ci.nsIWebProgressListener.STATE_IS_NETWORK)
       this._delayedCapture(aBrowser);
   },

   async _capture(aBrowser) {
     // Only capture about:newtab top sites.
     const topSites = await this._topSiteURLs;
-    if (!aBrowser.currentURI ||
-        topSites.indexOf(aBrowser.currentURI.spec) == -1)
+    const index = topSites.map(l => l.url).indexOf(aBrowser.currentURI.spec);
+
+    // if this is not a top site, do not collect a screenshot
+    if (!aBrowser.currentURI || index == -1)
       return;
+
+    // at this point we know it's a top site, but now we check if it has a rich
+    // icon already, and if so we don't bother getting a screenshot
+    if (topSites[index].hasRichIcon)
+      return;
+
+    // at this point we know it's a top site and we don't have a rich icon to show
+    // so it's ok to get a screenshot for this site
     this._shouldCapture(aBrowser, function(aResult) {
       if (aResult) {
         PageThumbs.captureAndStoreIfStale(aBrowser);
       }
     });
   },

   _delayedCapture: function Thumbnails_delayedCapture(aBrowser) {
@@ -207,29 +212,29 @@ var gBrowserThumbnails = {
     } else {
       // idle callback dispatched
       window.cancelIdleCallback(timeoutData.id);
     }
   }
 };

 async function getTopSiteURLs() {
+  // The _topSiteURLs getter can be expensive to run, but its return value can
+  // change frequently on new profiles, so as a compromise we cache its return
+  // value as a lazy getter for 1 minute every time it's called.
+  gBrowserThumbnails._topSiteURLsRefreshTimer =
+    Cc["@mozilla.org/timer;1"].createInstance(Ci.nsITimer);
+  gBrowserThumbnails._topSiteURLsRefreshTimer.initWithCallback(gBrowserThumbnails,
+                                                            60 * 1000,
+                                                            Ci.nsITimer.TYPE_ONE_SHOT);
   let sites = [];
   if (gBrowserThumbnails._activityStreamEnabled) {
     sites = await NewTabUtils.activityStreamLinks.getTopSites();
   } else {
-    // The _topSiteURLs getter can be expensive to run, but its return value can
-    // change frequently on new profiles, so as a compromise we cache its return
-    // value as a lazy getter for 1 minute every time it's called.
-    gBrowserThumbnails._topSiteURLsRefreshTimer =
-      Cc["@mozilla.org/timer;1"].createInstance(Ci.nsITimer);
-    gBrowserThumbnails._topSiteURLsRefreshTimer.initWithCallback(gBrowserThumbnails,
-                                                                 60 * 1000,
-                                                                 Ci.nsITimer.TYPE_ONE_SHOT);
     sites = NewTabUtils.links.getLinks();
   }
   return sites.reduce((urls, link) => {
-    if (link) urls.push(link.url);
+    if (link) urls.push({url: link.url, hasRichIcon: link.faviconSize >= 96});
     return urls;
   }, []);
 }

 XPCOMUtils.defineLazyGetter(gBrowserThumbnails, "_topSiteURLs", getTopSiteURLs);