Windows 10 reached EOS (end of support) on October 14, 2025. If you are on Windows 10, see this article.

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
  • 119 views
  • Paskiausią atsakymą parašė emp82
  • Archyvinta

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)

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

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.