Since I upgraded to Firefox 18, I’ve had blurry fonts on some sites, including Twitter and YouTube. Today I looked a bit into the problem, and found a solution in the Firefox Support forum.
In about:config, edit keys in the following way:
- Set layers.acceleration.force-enabled to true
- Set layers.acceleration.disabled to false
After doing that, restart Firefox and you’re ready to go.
Thanks for juanbaez for the tip!
If you don’t want to edit your configuration, I read that this is fixed in Firefox 19 as well. Downgrading to Firefox 17 reportedly works as well.