Join the AMA (Ask Me Anything) with the Firefox leadership team to celebrate Firefox 20th anniversary and discuss Firefox’s future on Mozilla Connect. Mark your calendar on Thursday, November 14, 18:00 - 20:00 UTC!

This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Preview Thumbnails on New Tab page empty only for certain URLs

more options

When I open a new tab, there are three certain preview thumbnails which are always empty, and there is no way I can make them show up again. They did work in the beginning, but at some time the three previews vanished and never came back. I have already tried to empy the cache and reload the sites as suggested here, but the thumbs are still empty. It's always the same three URLs where this happens. I have also cleared the history, opened the sites again and dragged the items from the history menu into a thumbnail - same result.

When I open a new tab, there are three certain preview thumbnails which are always empty, and there is no way I can make them show up again. They did work in the beginning, but at some time the three previews vanished and never came back. I have already tried to empy the cache and reload the sites as suggested here, but the thumbs are still empty. It's always the same three URLs where this happens. I have also cleared the history, opened the sites again and dragged the items from the history menu into a thumbnail - same result.

Chosen solution

You can open the Web Console (Web Developer > Web Console;Ctrl+Shift+K) and click the entry of the main (index) page to inspect the response headers.

You can reload web page(s) and bypass the cache to refresh all files files.

  • Press and hold Shift and left-click the Reload button.
  • Press "Ctrl + F5" or press "Ctrl + Shift + R" (Windows,Linux)
  • Press "Cmd + Shift + R" (MAC)

See also:

Read this answer in context 👍 0

All Replies (4)

more options

The pages may be send by the server with a no-cache or no-store header preventing Firefox to store that pages in the cache.
Firefox will only generate thumbnails if the page is in the cache.


The thumbnails on the about:newtab page are generated from the cache, so if the page is not in the cache or otherwise can't or won't (secure pages) be rendered as a PNG image then you will get an empty box.

  • Do not use Clear Recent History to clear data like the cache and the history when you close Firefox

If there is no history then you get an about:newtab page with empty boxes (no URLs).

  • bug 756881 - New tab thumbnails not displayed (or old images displayed) for Facebook, Twitter (sites using Cache-Control no-store)
more options

How can I find out if this is the case? I found no "no-cache" tag or something like that in the HTML source. I used to think it worked on another computer, but now I cleared its cache as well and the previews are gone there too. So it could ineed be a general problem with the sites.

Modified by SubjectDelta

more options

Chosen Solution

You can open the Web Console (Web Developer > Web Console;Ctrl+Shift+K) and click the entry of the main (index) page to inspect the response headers.

You can reload web page(s) and bypass the cache to refresh all files files.

  • Press and hold Shift and left-click the Reload button.
  • Press "Ctrl + F5" or press "Ctrl + Shift + R" (Windows,Linux)
  • Press "Cmd + Shift + R" (MAC)

See also:

more options

I couldn't find the relevant headers in the web console straightaway, but I found a web site that displays these headers for a given URL. It looks as if the no-store header is the culprit. All the pages without previews have it.