3 Tweaks Which Make Firefox 6 Faster

I hadn’t experienced speed issues with Firefox until recently. The problem appears to affect those who upgraded to Firefox 6, but I suspect it impacts versions 4 and 5 and those who did a fresh installation. If it hits you, the browser will become increasingly sluggish: tab switching, page loading, JavaScript execution, CSS hovers and even typing text into an input box are agonizingly slow.

Fortunately, there are at least three options which can fix Firefox’s lethargic performance.

1. Clear the History

Older versions of Firefox allowed you to set the number of days Firefox retained browsing history. The option has been removed in version 6 and your history will be retained indefinitely (there are about:config options, but it’s not clear how these impact the size or efficiency of the data set).

For me, clearing the history had the most dramatic impact on speed. Click the menu > History > Clear Recent History (or Ctrl + Shift + Delete on Windows):

Firefox 6 clear history

Choose “Everything” in the time range, then ensure “Browsing & Download History” is checked. Optionally, you could select every option if your speed issues aren’t rectified. Click “Clear Now” and, once it’s complete, restart the browser.

If the speed issues re-occur, you can configure Firefox to clear the history when it’s closed. Select the Privacy tab in the Options dialog and check “Clear history when Firefox closes”. The Settings button allows to you specify which data is cleared:

Firefox 6 history options

However, be warned that automatically clearing the history also wipes Panorama’s tab groups. Let’s hope Mozilla address that soon…

2. Clear the Cache

The latest versions of Firefox implement automatic cache management which should, in theory, use the best settings for your PC. I’m not convinced. On my installation, the cache was approaching 1GB and it was probably taking Firefox longer to locate a file than downloading it again.

To fix the cache, open the Options dialog, click the Advanced tab, then Network:

Firefox 6 cache options

Hit “Clear Now” and make yourself a coffee. It may take several minutes and Windows installations often report that the application has become unresponsive. Don’t worry and let it complete.

Now, check “Override automatic cache management” and limit the cache to 50MB.

3. Disable Hardware Acceleration

This may be counter-intuitive, but many users are reporting that hardware acceleration can have a negative impact on Firefox’s performance. The fix didn’t noticeably affect my installation so perhaps it depends on your OS, graphics card, drivers or other factors.

To change hardware acceleration settings, choose the Advanced tab in the Options dialog, followed by the General tab. Then uncheck “Use hardware acceleration when available”:

Firefox 6 hardware acceleration

Restart Firefox and check the speed. You can re-enable acceleration if there’s no discernible difference.

If All Else Fails…

If speed remains problematic, you may need to create a new profile or completely uninstall Firefox then install again.

Or switch to Chrome.

I hope these tips help you. My installation has become usable again.

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  • Anonymous

    Clearing my history to speed up Firefox would be like cutting my own nose off to spite my face. The AwesomeBar relies on history as well as bookmarks, and I find its functions invaluable in day-to-day usage.

    • http://twitter.com/craigbuckler Craig Buckler

      If you’ve not experienced speed issues, you won’t need to clear the history. However, for me, the browser had become unusable so clearing it was a small price to pay.

      My history hadn’t been cleared since installing Fx4 but it’s bizarre how it affected performance. Why should a CSS hover state take a second to appear?

      • Anonymous

        That does seem odd. How many days of history do you tell it to save? I have mine set to 180 days, and I’m a heavy surfer, but I haven’t as yet experienced any problems of the sort that you describe.

  • http://scorcher.org/ Jym Dyer

    =v= Clearing the cache has always been the biggest win, particularly for a certain operating system with hapless memory management. Clearing out cache, history, and especially cookies is a good privacy measure anyway.

    The newer releases give you pretty fine control over history. I generally only keep the last month or two around, but every now and then I might peruse the history from three months ago for links I may want to keep handy.

  • http://viewsouthcarolinarealestate.com markbrian

    I only have problems with certain add-ons, otherwise this version of Firefow has worked OK for me so far.

  • http://twitter.com/craigbuckler Craig Buckler

    Until recently, I’d never experienced problems either. As mentioned, these fixes are possible solutions if you’re having performance issues in Firefox. For me, the change was dramatic – but everyone’s installation will be different.

  • Alex Hall

    The only slow issues I encounter with Firefox are due to add-ons. In fact, Firebug seems to constantly slows things down until I “Stop script”, and I had the same for the RSS ticker today. Other than that I have 23 tabs currently open and it’s running perfectly fine on a not great Windows installation.

  • Lior

    I had the same issues on a brand new laptop with a fresh copy of Windows 7 and brand new install of FF6. I found that the performance was somewhat sluggish for pretty easy tasks. Not only that but every time I was using FF the system fan would always turn on, which is quite unusual given that I’m only browsing the Internet. For example, whenever I edit a WordPress post, I noticed that there was a delay typing and deleting characters. This is quite an unusual problem for a quad core processor with 8 gigs of RAM and almost nothing else running in the background.

    After playing around with different browsers and performance settings (suspecting that there was something wrong with my display settings), I narrowed down the problem to FF. I found that disabling hardware acceleration made a big improvement and there were no adverse effects on video streaming. All my drivers are current so I don’t know whether it’s a bug or on who’s end. Another thing people can try is to limit the size of the cache to somewhere around 50 to 100 MB as you have mentioned. You don’t need to have 1 gig worth of cache even if you have the capacity.