The release of Safari 4 and Firefox 3.5 release candidate 2 available for Mac I wanted to know which browser performs the best. Other websites have performed benchmarks comparing a bevy of browsers within a Windows environment. While the results may be similar, Internet Explorer and Google Chrome are not available for Mac (Chrome is currently in Alpha). I wanted to provide a benchmark for Mac users comparing the two major browsers in their ability to render JavaScript, their ability to display websites, the amount of memory they used, and their adherence to web standards. For this test I compared Safari 4.0.1 and Firefox 3.5 Release Candidate 2 using my 2.66 GHz MacBook Pro 17” with 4 GB of RAM.

JavaScript Performance

Safari 4 and Firefox 3.5 sport new JavaScript engines. In today’s Web 2.0 world, websites are becoming increasingly dependent on JavaScript to provide useful and powerful features. The faster a web browser is able to manage JavaScript the quicker today’s web experience would be. Using the SunSpider JavaScript Benchmark, I ran two tests and compared their results. In each test, Safari 4 clocked faster than Firefox. In individual tests, there were Firefox was significantly faster than Safari, especially during the Math computation. Overall, Safari 4 runs JavaScript faster than Firefox 3.5 RC 2.

See the Full JavaScript Benchmark Results

Browsing Speed

Apple claims Safari 4 is the fastest browser available, a claim that has been disputed. The question asked here is if Safari 4 is faster than Firefox 3.5 and by how much? To compare the speeds of each browser, I chose 11 websites (my website, plus 10 other popular sites) and used the development tools in each browser to determine their loading speed. In Safari this meant using the integrated developer tools, and in Firefox I used the Firebug plugin.

While there are several factions that can limit the speed of a website (such as the way the website is coded, the amount of images and files used to display a website, and bandwidth), a majority of this relies on the browsers ability to interpret that information. To help compensate for any errors, I loaded each page without using the browsers cache, and then with the browsers cache several times and recorded the highest load speed possible.

Safari 4 vs. Firefox 3.5 RC 2 - Website Performance. Click For Full Results

Safari is a very fast web browser, and for websites like the New York Times speed matters. It’s able to load a massive amount of content quickly. When a website is visited for the second time, Safari becomes faster, in some cases speeding a website’s display time by nearly half. There are some cases were Firefox is faster, especially with Google websites. The presentation of search results look different in Firefox than they do in Safari, and even load a bit faster. Overall, Safari 4 takes the crown in speed!

Memory Use

Memory use is always a concern. The amount of memory a browser uses helps determine it’s footprint and use of resources on a system. In order to test the browsers memory use, I compared each browser against 1 website (mine), 5 websites in tabs (mine including 4 others) and then all 11 websites used in the speed test. By using the Activity Monitor I recorded each browsers memory use.

Safari 4 vs. Firefox 3.5 RC 2 - Memory Use. Click for full results

Between the two browsers, Firefox is the clear winner. Firefox uses significantly less RAM across all tasks. With 11 tabs open, Firefox uses a significantly less RAM than Safrai, almost half the amount. My assumption is, Firefox’s low memory use can be explained by it’s ability to include extensions. Firefox’s footprint grows when extensions are installed, the less RAM Firefox uses, more can be available for installed add-on’s and extensions. Even with several extensions installed, Firefox tends to use less RAM than Safari.

Standardization

I highly believe in web standardization. Code should display the same way across all browsers. The best way to measure this is by pitting the web-browser against the Acid Test. Both Firefox 3.5 and Safari 4 pass Acid1 and Acid2 Tests with 100%, but only Safari 4 passed the Acid3 test with a complete 100/100 score, Firefox 3.5 obtained a slightly lower score of 93/100.

Conclusion

Safari 4 runs better than Firefox based on these benchmarks. While Firefox uses less memory, Safari 4 blows past it when handling web-sites, javaScript and web standards. This is only comparing the browsers benchmarks, not their features or ability to customize. If your concerned about speed on a Mac, Safari 4 is the browser to use.