Since the new Firefox 4 is out, many people are being brought to my website again, because they searched for keywords like “anti-aliasing”, “ClearType” or “font smoothing”. They then discover my two year old article Anti-Aliasing in Firefox, which describes how to enable ClearType in Windows XP – where it is not enabled by default after installation.

But with the new Firefox, some people still get blurred and illegible fonts, even though they have ClearType enabled. The problem seems to be fairly widespread, as this thread in the Mozilla forum shows, and apparently it happens most frequently with ATI graphics cards. I’m pretty sure the problem will be fixed soon, but for the moment I have found two different solutions:

1. Enter about:config in the address bar, find the key gfx.direct2d.disabled and double-click it, so the font turns bold and the value changes to “true”.
2. Install the addon Anti-Aliasing Tuner and try various settings, until the font looks good. I myself only needed to go to the “Large Font” section and change “Anti-Aliasing Mode” to “Default” and “Rendering Mode” to “GDI Classic”.

It seems that many people don’t consider the first option a real solution, because it will disable hardware acceleration, which, in their opinion, is just one of the greatest improvements of the new browser. Personally, I haven’t noticed any difference while surfing, however, I opted for the addon on principle. ;)