Making Firefox as Fast as Chrome

Written by | 8 minutes read | Tags howto, browser, firefox, chrome | Comments

Learn in this article how you can make Firefox as fast as Chrome again.

I can remember that in the past some coworker says to me: “Why are you using Firefox and not the faster Chrome?” Hmm, I have always been using Firefox and never saw a reason why to use another browser. But I installed Chrome, it feels faster, and it consumes less CPU and memory of my system. The ecosystem and the look and feel is typical for a Google product: It works, is intuitive, and you know it works. It is not difficult to sync your bookmarks, settings, prefill forms, and even passwords => just everybody has nowadays a gmail account and this is how all the magic works.

But being a German, it always felt wrong to send Google information about my web experience, which buttons I press, what plugins I use and so on. Since I’m a big Vim fan I heard of a plugin called Vimium which enables keyboard shortcuts for navigating webpages without using the mouse, I installed it but was not really happy with it because it hasn’t all the shortcuts I really want and it was difficult to create custom mappings, as well as handling bookmarks. Than during a vimberlin meetup I saw @andrewradev using Vimperator and it was a blast: He was very fast and doing all the things I wanted but never could do with Vimium. That was a turning point to give Firefox a new chance. I spent one weekend to learn most of Vimperators shortcuts and create a vimperatorrc.

But than came the release of Xubuntu 13.10 and I installed a fresh new system …

Slow Firefox

After everything was installed and I was ready to use the new system. Starting Firefox was a nightmare, everything is slow. Thanks to my friend @jcavena from Kansas City - he gave me starting point to solve this issue and not spending more hours on it:

I didn’t had any plugins, only the basic installation with the default settings. I spend the evening fiddling around with the settings, tried this and that, checked my Internet connection, but all what I did was senseless. Firefox was loading 2000 times slower than Chrome. But don’t give up in such situations, just clear your mind and think about what you want solve.

Fast Firefox

I stick around the Internet and found the about:config setting in Firefox (it’s nearly the same when you call the chrome://settings/ URL in Chrome but has more options). This is the place where you can change security, stability, and performance. That what I was searching for and this is the place you can’t find in the normal graphical settings of Firefox. There you can see a list preferences names with either string, integer, or boolean values. Than I stumbled upon the network.dns.disableIPv6 option. There is an error in IPv6-capable DNS servers where an IPv4 address is returned although an IPv6 was requested. Firefox can recover from this error but due to lack of performance. So my solution was to setting this option to true.

Reduce Firefox Memory and Cache Usage

Next, create the config.trimonminimize as a boolean value and set it’s value to true. This will swap out memory when the program is minimized.

If you have enough memory, you can set the browser.cache.disk.enable and the browser.cache.memory.enable value to false.


Set the values of network.http.pipelining and network.http.proxy.pipelining to true. Next set the value network.http.pipelining.maxrequests to 8. This in combination with the pipelining options, Firefox will send 8 requests to a page and this results in a faster load of the page.

Create the new value nglayout.initialpaint.delay with the value of 0. This will load a page initially but take longer till the whole page is rendered. Normally, Firefox renders web pages incrementally, it displays what’s been received before the entire page has been downloaded.

Fast Rendering

Create the new value content.notify.interval to 500000. This preference specifies the minimum amount of time to wait between reflows to ½ of a second. Lowering the interval will lower the perceived page loading time but increase the total loading time. To make use of the content.notify.interval setting you need to add the boolean setting content.notify.ontime to true. This means that pages are not reflowed at an interval any higher than that specified by the content.notify.interval.

Frequency Mode

Create the new value content.switch.threshold and set it to 250000. When a page is loaded, there is a high frequency and low frequency level. The high frequency mode is active when the user moves the mouse or uses the keyboard - so it allows higher UI responsiveness. On the other hand, the low frequency mode is on, when the user is reading the page. Raising the value will make the application more responsive at the expense of page load time. In order to make use of this option, you need to create the new value content.interrupt.parsing and set it to false. Parsing a page will not be interrupted by user and the page is loaded faster. But that means, that the application is unresponsive until the parsing the site is complete.

Session History Entries

Set the browser.sessionhistory.max_entries to 5 - you won’t surf more than 5 of the websites we previously surfed before, and there is really no need to store more than that in the session.

Increase Page Loading

Next, create the new value nglayout.initialpaint.delay, chose a new integer type and set the value to 0. This will speed up page loading by intentionally telling Firefox to avoid waiting during certain parts of page loading.

Further Improvements

The following improvements are based on Gheorghe Sarcov.

Final Thoughts

There is not the perfect setup here for everyone. You can type in about:cache?device=memory and see your current number of entries, maximum storage size, storage in use and inactive storage. Chrome make better use of a modern multi-core CPU, as described under - where Firefox uses a single-process architecture.

Further reading