Firefox 4 Review: Benchmarks and Usage Feel

The newest version of the Mozilla web browser, Firefox 4, went through a long developing stage, the first beta being available since January 2010. Meanwhile, the expectations from the users of the old Firefox 3.6 grew higher and higher as specially because the other developers have been very productive and the alternatives are tempting.

Thankfully, the wait is over! Firefox 4 has lived up to all expectations. The Interface of the old Firefox 3 has been upgraded to a new and much more optimized one. Behind the flashy interface, we have a completely new browser, the source code has been all but rewritten and it has many optimizations for speed and support for the newest technologies.

The tests show that the browser has a very high compatibility. Taking the Acid 3 test, which is one of the most powerful tools for evaluating the compatibility for web browsers, Firefox 4 does not disappoint, scoring a impressive 97/100 points and is rated higher than Internet Explorer 9 with 95/100 and is at a tie with the newest Opera 11.1. Although it didn’t score as much as Google Chrome, who is the undisputed leader  with 100/100 points!


Using Sunspider JavaScript Benchmark 0.9.1, who can test very precise the speed of a web-browser. During the tests, we opened more than one tab in every browser.

Sunspider JavaScript Benchmark 0.9.1

  • Internet Explorer 9 – 359.2ms +/- 2.3%
  • Opera 11.01 – 393.0ms +/- 0.3%
  • Firefox 4.0 – 405.8ms +/- 0.7%
  • Chrome 10 – 424.0ms +/- 1.7%

Peacekeeper Benchmark

  • Chrome 10 – 6605
  • Opera 11.01 – 5991
  • Internet Explorer 9 – 3662
  • Firefox 4.0 – 2831

As you can see, the benchmarks placed Firefox 4 almost at the bottom of the list. We can definitely say that Firefox 4 needs some optimizations if they want to compete with the other web-browsers.

In tests, the speed of the browser is quite good and it behaved just as expected and we did not notice loss of speed when comparing with the other browsers. This being said, we can say that in normal user usage, you will not be able to notice any loss of speed.

Thus, it is still your very own speedy browser for normal usage..

  • Jose Jimenez

    I installed it and I like it on the whole. There are a few changes which take a bit of getting used to though. Some add-ons like Delicious don’t work or not yet anyway.

    The ability to group tabs together is cool. I have lots of tabs open so organising them helps. The tabs being higher up is better imo. Speed wise its good. I haven’t really used Chrome that much but it seems to be getting a lot of press and recommendations so I may check it out. Thanks for the article/review.

  • Techgopal

    it works g8 4 me…..

  • Magazine Subscriptions

    I like it so far. It’s certainly much faster than 3.6 and looks much slicker. But it can still be improved. It still uses a ridiculous amount of memory, and the ability to open a second Firefox window from a quick start button has gone – you have to do it within the current window now. Also, in 3.6 you could click on the back button and see the last 8 or so pages, enabling you to skip straight back to a specific page recently visited. This option has vanished. I hope they bring this back.

  • Free Icons

    Thanks…….Mozilla FireFox 4 Just Great. :)