The Setup
To do some benchmarking I downloaded the “mootools-developed” Slickspeed PHP framework from it’s Google Code hosted location, along with XAMPP to serve up the PHP pages required for the tests.
Hardware
- 2007 Compac nc8430
- Intel Dual-Core T2500 @ 2.00GHz
- 1.00 GB RAM
Software
- MS Windows XP Professional SP 2
- XAMPP 1.6.7
- Slickspeed (svn trunk version)
Browsers
- Safari 3.1.1
- Opera 9.5.2
- Firefox 3.0.1
- Internet Explorer 7.0.5730
- Chrome 0.2.149.27
JavaScript Libraries
- Mootools 1.2
- jQuery 1.2.6
- Prototype 1.6.0.2
I only downloaded 3 JS libraries because I thought that was enough to tell the difference between the browsers; this isn’t meant as an exercise at “who has the fastest JS library”.
To generate the results I installed XAMPP, installed slickspeed and set it up with the 3 JS libraries; then I opened each browser one at a time and ran the local copy of the slickspeed test:
This test runs 40 different CSS selector tests with whatever JS libraries you have configured atainst this W3C document. Each test is run separately in separate IFRAME tags as not to interfere with one another and report false data.
Data Collection
Data was collected by running the above slickspeed setup 10 times for each browser. After each time the test was ran, I recorded the final time for that browser.
** I used the final time in the slickspeed test because I was testing for the overall effectiveness & speed of the browsers. If you want to see how it performs on a per test basis, run it yourself!
The Results
Mootools 1.2 Results
Mootools used to be my favorite JS library. It has some cool features that make it pretty nice (like a stab at code organization using the Class object).
Safari operated the best with the Mootools library. Opera started out as a good candidate; however, the longer you kept open the browser and the more times you ran the test, the worse the response time got. Opera will show the same results for other libraries as well.
IE sucks, Firefox is good, Chrome is pretty darn good.
JQuery 1.2.6 Results
What is up Opera? You leaking stuff? No JS garbage collection? I did “hard” refreshes so the caches would be expunged; I just don’t get it.
Chrome and Safari FTW. IE bad, bad, bad.
Prototype 1.6.0.2 Results
Prototype made IE 7 look like the biggest piece of junk in the world; I have since then see the same results in YUI. The IE results are an order of magnitude greater than the speeds of any of the other browsers combined. Keep in mind that less is better.
This was an extremely disappointing test; moreover, Opera still showed signs of memory leaks and slowly increasing final result times.
Chrome wins this battle; Safari a close second, and almost every other browser is not far behind. Yuck IE!
Final Results
So now we decided to take the average of all 10 tests and put it onto one chart so you can see the important stuff all summed up.
Final result conclusions…
- Chrome did very well considering it’s a partial mesh of Safari and Firefox components.
- Safari on a local copy of slickspeed did surprisingly very well.
- Opera is okay if you view a web page and then restart the browser. Otherwise, JS applications become slower and slower.
- IE needs a lot of work (but who didn’t know that already)

Your conclusions about Opera are doubtful - using memory doesn’t automatically slow down the browser unless it’s starting swapping to disk.
It’s entirely possible that Opera runs slightly slower because it is doing garbage collection - it could be that FF is the one not reclaiming its memory.
Try changing your Opera memory cache settings away from Auto, and to a fixed size, see if that changes the results.
I’d like to see these tests using the bleeding edge alphas of Safari and Firefox.
I use Opera as my main browser and sometimes keep it open for *weeks* (I rarely reset my computer - just put it to sleep), and I haven’t noticed any such speed degradation.
BTW: on Prototype’s graph you’ve got Prototype instead of Opera.
BTW2: Could you add IE8 to the results?
@kL. Fixed. Thanks for the catch.
Google’s chrome ..really rocks
Mosty we hit the following websites daily google,orkut,youtube “”"almost all are google’s”"
Dear, these web pages have excellent compatibility with chrome and opens like anything..even other webpages gets loaded quicker than ever it was.
and the last but not the least its user interface is better than all other brownser’s ..
It seems google is going to dominate in what ever there are creating…
I don’t understand the mootools test.
How come safari beats chrome in every mootools test but in the summary comes out second?
Did you get the colours mixed up? Did you get jquery and mootools the wrong way round in the summary?
@Mike. Good catch. Yes you are correct. Google Chart API is cool but man, it is simple to screw up. Thanks!
Isn’t the IE results for the mootools test supposed to be under prototype?
@James. Good find. Thanks!