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why has the font size changed


After the upgrade to 22.0 the font size of all my windows has changed.

Chosen solution

The theme and font extension is much easier to use than changing the PixelsPerPx. I tried it and it decreased the size of my tool bar and menu bar. But I saved the site just in case.


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Additional System Details

Installed Plug-ins

  • Google Update
  • Shockwave Flash 11.7 r700
  • Adobe PDF Plug-In For Firefox and Netscape 11.0.03
  • RealPlayer(tm) LiveConnect-Enabled Plug-In
  • RealPlayer Download Plugin
  • RealNetworks(tm) RealDownloader Chrome Background Extension Plug-In
  • RealNetworks(tm) RealDownloader PepperFlashVideoShim Plug-In
  • RealNetworks(tm) RealDownloader HTML5VideoShim Plug-In
  • RealDownloader Plugin
  • Next Generation Java Plug-in 1.6.0_41 for Mozilla browsers
  • NPRuntime Script Plug-in Library for Java(TM) Deploy
  • 5.1.20125.0
  • WildTangent Games App V2 Presence Detector
  • Garmin Communicator Plug-In
  • The Hulu Desktop Plugin allows Hulu.com to integrate with the Hulu Desktop application.


  • Firefox 22.0
  • User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:22.0) Gecko/20100101 Firefox/22.0
  • Support URL: http://support.mozilla.org/1/firefox/22.0/WINNT/en-US/


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  • avast! Online Security 8.0.1489 (wrc@avast.com)
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  • FirePHP 0.7.2 (FirePHPExtension-Build@firephp.org) (Inactive)
  • Freeze.com NetAssistant 3.6.5 ({1266764D-FC4F-4FA7-B63B-884D53B1680F}) (Inactive)
  • TopArcadeHits 1.0 ({0113D088-8ED1-468C-B225-585A9C53B5E3}) (Inactive)


  • incrementalGCEnabled: True


  • adapterDescription: AMD M880G with ATI Mobility Radeon HD 4200
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Modified Preferences

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  • browser.startup.homepage: garykozlowski.com/A_Homepage/homepage.html
  • browser.startup.homepage_override.buildID: 20130618035212
  • browser.startup.homepage_override.mstone: 22.0
  • browser.urlbar.autocomplete.enabled: True
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  • User JS: Yes
  • Accessibility: No
  • Top 25 Contributor
529 solutions 5045 answers

Helpful Reply


Firefox on Windows is now following display scaling options which may render text larger on high resolution displays. You can adjust your screen resolution. To modify it do the following:

  • Type about:config into the Firefox address bar and tap on the Enter key.
  • If the warning This might void your warranty appears, click I'll be careful, I promise.
  • Search for layout.css.devPixelsPerPx


  • Double-click on layout.css.devPixelsPerPx to modify its value. The default is -1.0 in Firefox 22 and above. Change it to 1.0 to make it work like in previous Firefox versions.

If necessary, further adjust the value in 0.1 or 0.05 steps. Use values between 1.0 and about 0.9 to reduce elements in size. Use values greater than 1.0 to increase size. For example, a value of 1.25 will increase font size to 125% to accommodate the default DPI setting in Windows 8. Double check the value that you enter. Setting a too small value will make everything disappear and a too large value will blow things up.

If web pages still need to be adjusted then you can look at the Default FullZoom Level or NoSquint extension.

To adjust the font size for the user interface, you can use the Theme Font & Size Changer extension.

Refer to Webpages are large and blurry after updating Firefox - how to fix

Did this fix your problems? Please report back to us!

Thank you.

Modified by Waka_Flocka_Flame

Question owner

Thanks for the help. I was really getting frustrated.

RadicalDudette 2 solutions 13 answers

Chosen Solution

The theme and font extension is much easier to use than changing the PixelsPerPx. I tried it and it decreased the size of my tool bar and menu bar. But I saved the site just in case.


brando_slc 0 solutions 1 answers

Pretty ridiculous that you now need an add-on to make pages display correctly with out-of-the-box Firefox.

GlobalRoamer 0 solutions 4 answers

Yes thank you for your kind answers, both contributors and Firefox creators. I KNOW HOW TO MAKE THE CONTENT PAGE LARGER AND SMALLER. Now that said, what happened to the text size on the Menu Bar, Tab Strip, and Navigation Tool Bar?

Please read this first before replying. I spend too much time fixing computer related stuff. This is not my hobby. I do not have time to test theories. Please post a real answer. Do not post guesses, or something your read. Please do not post programming solutions. I am not going to program this.

Please provide a real solution on how to fix TEXT SIZE OUTSIDE the content window.

Modified by GlobalRoamer

  • Top 10 Contributor
  • Moderator
3195 solutions 24393 answers

This extension lets you change the global font size and font family used for the user interface in Firefox.

GlobalRoamer 0 solutions 4 answers

Thanks for the try. This extension is obviously a work around and obviously in beta.

1. I don't know if the list of fonts was supposed to be all inclusive? But the list is missing a lot of fonts. For an example Tahoma, and Trebuchet are missing.

2. Some of the fonts that are on the list are malformed. For example I selected Futura Bk for my default font. The capital letters M, S, and A have missing pixels and make parts of the character look like it is missing. The same with the numbers 3 and 5.

3. My understanding was that this extension was not for changing the screen content, just the toolbar, menu bar, and tabs? Well the screen content changed also. When I enter in the TCP/IP address for my wireless router I cannot see the text on the router's GUI displayed on Firefox. I used to be able to, but no longer. No matter what font I choose, or how small or large I make the content. Firefox 23 just doesn't work. However IE 8 continues to work fine.

Someone please let me know when Firefox gets this solved or at least gets the work around, well working. In the mean time I need to install a browser I can count on. I don't have the time to become a Firefox expert nor do I want to waste any more time trying to understand and fix the problem.

Modified by GlobalRoamer

  • Top 10 Contributor
  • Moderator
10749 solutions 96724 answers

Try to disable hardware acceleration in Firefox.

mariooski1 0 solutions 1 answers

Helpful Reply

I have read all your posts with out result. I have reset font to larger size (10) but all the web sites r still small. I went to options and made it mandatory that they use my font with negative results. please advise as trhis microscopic print is going to drive me to another browser if this keeps up

  • Top 10 Contributor
  • Moderator
10749 solutions 96724 answers

Hi mariooski1

Which part of the Firefox window has small text?

Is that the user interface part (menu bar and other toolbars) or the browsing area that displays the internet pages?

What is the current setting of the layout.css.devPixelsPerPx pref on the about:config page?

What is your Operating System?