Last Updated on April 16, 2017 by Dave Farquhar
Firefox is a better browser than Internet Explorer by a long shot, but at times it’s made me wonder if it’s strayed from its original mission of being a lean, quick, simple browser based on the Mozilla engine.
I’ve seen several “Optimizing Firefox” guides and most of them talk very little about performance, and the ones I did find were not only disappointing, they also appear to be widely copied verbatim without attribution. So here’s what I do to shaq-fu Firefox into shape.Try out Firetune. Firetune is a wizard-like program that configures most of the common Firefox tweaks based on criteria you select. In my case, since I have a P3-700 with 192 megs of RAM, I selected Slow computer/Fast connection on the Performance tab, and Optimize Firefox memory usage on the tab labeled Other useful settings. For me, the payoff was immediate.
Install PDF Download. If you view a PDF file online, Firefox keeps Acrobat in memory essentially forever, where it does nothing but chew up precious memory until the next time you view a PDF, which might be in a minute, or it might be next month. Take control over this behavior by installing PDF Download.
By default, after installing PDF Download, you’ll get a dialog box asking what you want to do when confronted with a PDF file. If you click the View PDF button, it loads it in your OS default PDF viewer. This behavior is less seamless than viewing the PDF directly in your browser, but it’s much better for performance because after you close the file, the viewer unloads from memory. For even better performance, forget about Adobe’s Acrobat Reader and install Foxit Reader, which is much smaller and faster. By default, when you install Foxit Reader, it will make itself your OS default PDF viewer. Trust me, this is what you’ll want.
On my 700 MHz P3 running Windows 2000, PDF documents display in one second with PDF Download and Foxit Reader installed. That’s faster than Acrobat ever was, even if it was already in memory.
I like the combination so much, I went to Tools, PDF Download Options, and set the default action to Open PDF, rather than displaying the dialog box. Now I no longer dread downloading PDFs from the Web.
Optimize memory usage a bit more. Type about:config into a browser window and scroll down to browser.sessionhistory.max_total_viewers. The default value is -1, which will determine the number of pages in your browser history to cache based on the amount of memory you have. I set it to 1, since I do tend to use my browser’s back button a lot. If you almost never find yourself clicking the back button, or you have a very low-memory machine, set this to 0. Each page it stores takes up about 4 megs of RAM.
Clear your downloads. Hit ctrl-j to bring up the download manager and clear it out. Too many entries slows Firefox down, partly because it increases memory usage.
Keep your version current. Often newer versions of software are slower and fatter than the old versions, but newer versions of Firefox are often faster than older versions because memory leaks and performance problems tend to get fixed in newer versions. I don’t recommend running beta or preview release versions, and I’m not all that crazy about .0 versions either (when Firefox 3.0 is released, I’ll wait until version 184.108.40.206 comes out). I just upgraded an old computer that had been running a very early Firefox 1.0 to 220.127.116.11, and the difference is incredible.
For what it’s worth, version 18.104.22.168 (the current version) running with these changes feels very zippy on a P3-700 with 192 megs of RAM.