How-To Geek

Enable Thumbnail Previews for Firefox in Windows 7 Taskbar

Are you tired of waiting for the official activation of Taskbar Thumbnail Previews in Firefox? See how easy it is to enable them now with a simple about:config hack.

Note: We have briefly covered this before but present it here in a more detailed format.


For our example we opened all of the websites in the HTG Network in tabs…


When hovering over the Firefox Icon in the Taskbar, you only see the one thumbnail. There are two things in particular to notice here:

1.) The Tab Bar for Firefox is displayed with all four tabs visible in the Thumbnail Preview 

2.) The “Taskbar Icon” itself is displaying as singular with no “fanned edge” on the right side.


Hack the About:Config Settings

To get the Thumbnail Previews working you will need to make a modification in the about:config settings. Type about:config in the Address Bar and press Enter. Unless you have previously disabled the warning you will see this message after pressing Enter. Click on the I promise! Button to finish entering the settings.


In the Filter Address Bar either type or copy and paste the following about:config entry:


After you enter that in, you should see the entry listing as shown here. At this point there are two methods that you can choose to alter the entry. The first method is to right click on the entry and select Toggle and the second method is to double click on the entry. Both work equally well…choose the method that you like best.


Once the about:config entry has been changed, you will need to restart Firefox for it to take effect.


After restarting Firefox on our system the Thumbnail Previews were definitely looking very nice. Notice that the Tab Bar is no longer displayed in the Thumbnail Previews.


The Taskbar Icon also had a “fanned edge” indicating that multiple tabs were open.



If you are tired of waiting for Mozilla to officially activate Taskbar Thumbnail Previews in Firefox, then you can go ahead and start enjoying them now. For more great Firefox 3.6.x about:config hacks read our article here.

Akemi Iwaya is a devoted Mozilla Firefox user who enjoys working with multiple browsers and occasionally dabbling with Linux. She also loves reading fantasy and sci-fi stories as well as playing "old school" role-playing games. You can visit her on Twitter and .

  • Published 05/17/10

Comments (25)

  1. Butch

    Good stuff as usual…

  2. Kalle

    How can I do this with Chrome?

  3. Tom Thorogood

    Mozilla now activate Taskbar Thumbnail Previews by default in Firefox 3.7 (Minefield). So we should see it soon in future releases. The option is still there in 3.7 but it is set to true by default.

  4. Richard

    Doesn’t seem to work for tabs in Windows 7 64-bit, at least for me. Fanned edges display. Multiple windows works but not for multiple tabs.

  5. KBPrez

    @Richard, give it another try. I use Win 7 Home Premium x64 and it’s working fine.

    THANKS Geeks!

  6. roger

    Now on my Windows 7 32-bit I get the seperate thumbnails for each tab but I don’t get the fanning of the taskbar icon

  7. socalgal

    Wrong tab (ironically) previous comment should have been for the Explorer -> Libraries hack :-(

  8. Wil

    Didn’t work for me either (win7 32bit) I even rebooted. I must have add-ons that interfere with it.

  9. neowster

    works great for a portable 3.6.3 firefox. thanks.

  10. Sammy

    Wow, it really worked, took just 1 minute and its changed.


  11. Enzer Milliard

    Before I turn it on and destroy my Firefox because I have over 200 tabs open at any given time I must ask: what happens if I have over 200 tabs open at any given time? It seems like something that would just crash firefox (or more likely explorer, or both) for some reason or another, but I’ve never had anything in my taskbar that would be so cumbersome so I don’t know.

  12. Tarun Iyer

    Spent a good 20 minutes furiously trying to get this to work. Then realised i was on my desktop that is running Vista!


  13. Starterz

    No need to restart Firefox, it happens the second you make the about:config hack.

  14. eidylon

    @Enzer, there is another config setting “browser.taskbar.previews.max” which theoretically should help you and limit the # of tabs shown in the previews.

    Unfortunately I can’t test it because I am one of the unlucky ones for whom this is not working – interfering addon? Perhaps… would be cool but I’m not that interested to start trying to figure out which addon killed it.

  15. Mifas

    Thanks Admin. Work fine… It is very easy to get this hack…

    yes no need to restart the firefox..

  16. Will

    Perfect. ‘Just what I was looking for.

  17. Marlene

    Need help!! I tried this and not working!!
    I just recently (admittedly a novice) reformatted my computer, Windows 7 Home Premium, please don’t ask why but I did. Anyways, personalizing my settings, I’m noticing that my taskbar buttons are different then before and cannot seem to change it. My taskbar buttons “list” my windows, not “thumbnail preview”
    Can somebody please help me?

  18. Asian Angel

    @Marlene – Do you have Aero enabled on your system? If not then that will cause lists to display instead of thumbnails…

  19. Marlene

    @Asian Angel – I do have Aero and as far as I know it is enabled, not sure how to find out for sure.
    Appreciate the help. :)

  20. Asian Angel

    @Marlene – Right click on your desktop and select Personalize. When the themes section opens up make sure that you have an Aero theme selected/enabled as opposed to the Basic Theme, etc. ^_^

  21. Marlene

    Yup, that’s the way I have it set. :(

  22. Asian Angel

    @Marlene – Is the same problem occurring with other software such as browsers, photo programs, etc?

  23. Marlene

    Yup, :(

  24. Asian Angel

    @Marlene – Ok, that is definitely a system thing then. :( :( My best advice for that is to go to the Microsoft website (and associated forums) to see what kind of solutions they know of for the problem.

  25. PP

    Looks too pixelated, anyone know how to get it bitmapped?

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