When I load a page with a fair amount of code or long code sections, my browser (see below) halts and the CPU spikes to 100% (For a little bit, doesn't actually crash the browser).

Is this just me? I imagine since this is happening it is Javascript or CSS putting too much load on my Firefox?

  • Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.1) Gecko/20090624 Firefox/3.5

3 Answers 3


Firefox 3.5 had some serious JavaScript performance bugs. Upgrade to 3.6.

  • 1
    Seeing that he is on Linux, there may be a fixed release cycle... So the real solution is to upgrade to Arch Linux where everything is always up to date :)
    – Earlz
    Commented Apr 30, 2010 at 16:05
  • @Earlz: just be careful and backup your config files before updates and set aside a few minutes to reconfig, just in case. Generally it all *just works*™, but sometimes the upstream apps change their config files (awesome has been guilty of this in the past).
    – perbert
    Commented Apr 30, 2010 at 16:35
  • Just added the repository for latest firefox in Ubuntu and updated it (I use optimized swiftfox version) and it is all good now. Actually, the performance in general is a lot better of these sites. Thanks! Commented Apr 30, 2010 at 16:43

I had the same problem (using Windows XP) until I switched to Firefox 3.6.


It's not your fault, Firefox is simply a bloated mess. Seriously, it went from 3.0 to 3.5 in the blink of an eye.

I switched to Chrome till Firefox can get it's act together.

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