Where did you install Firefox from? Help Mozilla uncover 3rd party websites that offer problematic Firefox installation by taking part in our campaign. There will be swag, and you'll be featured in our blog if you manage to report at least 10 valid reports!

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Firefox 4 is VERY slow rendering opacity values from javascrit

  • 2 replies
  • 249 have this problem
  • 14 views
  • Last reply by emp82

more options

Firefox 4 is extremely SLOW in websites which use javascript to "play" with opacity. As you can see on www.emoure.com (when you open an image).

Firefox 4 is extremely SLOW in websites which use javascript to "play" with opacity. As you can see on www.emoure.com (when you open an image).

Modified by emp82

All Replies (2)

more options

I experienced similar issues with very slow behavior in the java script area. What helped me was to uninstall Firefox 3.6 and 4.0. After that I re-installed Firefox 4.0 and the thing was fast again. Also the www.emoure.com was fast.

I have the feeling that in the migrations of settings/add-on's/etc from 3.6 to 4.0 something goes wrong.

Good luck,

Jan Labrie

more options

Hi JanLabrie,

Maybe that solution fix the problem because you use Windows. In my case ( Mac X OS ) the problem persist after reinstall  :( ...

Definitely there is a problem with Firefox 4 + JavaScript + Mac X OS

Enrique Moure.