Hi ethic,

To help could you give me a bit more information.

Did this happen suddenly? Or after an update?

Are you using the latest version of firefox (12)? If not please upgrade.

Just to confirm: the problem is not with websites but only with Firefox's own text, menu items etc?

Please test to see if the same problem occurs when firefox is in safe mode. Follow these instructions: Diagnose Firefox issues using Troubleshoot Mode. If the problem does not appear in safe mode then one of your add-ons or themes is causing the problem.

Firefox may have switch to a different font for some reason because the default font for the user inter face wasn't found or got corrupted.

You can use this extension to adjust the font size for the user interface:

• Theme Font & Size Changer: https://addons.mozilla.org/firefox/addon/theme-font-size-changer/

Hi,

This happened suddenly and not after an update.

This is not the very latest version of Firefox. The release notes of the latest version do not address this problem. Updating to the latest version would disable many add-ons and cause other problems. The frequency of new updates is too often.

Only Firefox's own font is tiny including the search, menu, tabs and title. There's no problem with text on websites.

The font is still small in safe mode.

Theme Font & Size Changer doesn't change the size in the Firefox title bar.

Try code like this in userChrome.css below the default @namespace line.

• http://kb.mozillazine.org/userChrome.css

The customization files userChrome.css (interface) and userContent.css (websites) are located in the chrome folder in the user profile folder.

• http://kb.mozillazine.org/Editing_configuration

@namespace url("http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"); /* only needed once */

#titlebar * { font-size: 11pt !important; } 

I made a userChrome.css file. No font sizes changed when trying the above code.

With the code below the page title at the top of the window next to the Firefox logo remained small. Like with Theme & Font Size Changer, only the other text changed but not the title

@namespace url("http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"); /* set default namespace to XUL */

/* Global UI font */

• { font-size: 11pt !important;

 font-family: Verdana !important; 

}