I have read a lot about the new Firefox 3.7 and Firefox 4.0 that should increase the speed and compensate for all the new features and CSS3 and HTML5 support that the competition has developed. By competition I mean mostly Google Chrome, Opera and partly Safari. Mozilla roadmap says that we can expect Firefox 4.0 beta release in the end of June 2010.

I have downloaded the latest nightly build of Firefox 3.7 preview from Mozilla FTP. The release I have downloaded was Firefox 3.7 alpha 6 preview dated June 12, 2010 (firefox-3.7a6pre.en-US.win32.zip). I have unzipped it to a new folder and gave it a test.

The GUI has changed slightly so it looks like it has a new theme. The responsiveness is better than Firefox 3.6.3, so I have decided to run some javascript tests. I have run the Sunspider benchmark in both browsers, but I have used a different profile. In the old version I have used my full profile and in the new version I have used a blank profile. The results were very impressive in the favour of FF 3.7. The test has shown a 1.41x improvement in speed (declared ‘significant’ by the test).

I have repeated the tests on the same (blank) profile in the older version of the browser and the results were still very similar. So it looks like that the new Firefox 3.7 will be 1.4 times faster than Firefx 3.6.

Just for the fun of it, I have run the same test in Chrome 6.0.427.0 (developer release in developer channel). This test should show how well Mozilla is prepared for the javascript speed competition between the browsers. The results have shown that Chrome is 2 times faster than Firefox 3.6.3 and is still 1.6 times faster then the preview of Firefox 3.7a6. I wonder what the tests with Firefox 4.0 will show.