Recently, new versions of jQuery and Prototype have been released – it’s a perfect moment for a part number 2. On the official Prototype blog we can read that the general performance of CSS selectors is now improved, unfortunately only for Safari 3, but Element#up/#down/#next/#previous should now be faster on all browsers, it’s a good news as they were really slow. On the other hand we have jQuery official announcement with information that jQuery is now 300% faster – we’ll see!

This time I made a step forward and decided to use a custom JavaScript-based testing environment instead of running tests using Firebug profiler. The obvious advantage is that I was able to run all the tests on 4 different browsers. New test cases aren’t much different then in the first part, let’s say it’s a modification of the previous ones with some extra operations and a little more complex HTML structure.

Test environment setup

Libraries:

• jQuery 1.2.2

• Prototype 1.6.0.2

All the tests were run on the following browsers:

• Firefox 2.0.0.11

• Konqueror 4.00.00

• Opera 9.50_beta1

• Internet Explorer 7 (but using Windows on VirtualBox!)

A tiny piece of JavaScript code is responsible for running the tests, each operation is called only once inside a try-catch block, so the essential part looks like this:

    try {
      var start = new Date;
      test();
      var end = new Date - start;
      this.writeResults(test, end);
    } catch(e) {
      test.resultCell.innerHTML = 'Exception caught: '+e.message+'';
    }

There is a 3 seconds break between each test run, results are automatically inserted into the results table. If you want, you can check it out on your own, just go right here and hit the ‘run tests!’ button.

The results

I’m happy to see that all tests pass on the latest Konqueror, previous version from KDE3 fails on some Prototype tests. I don’t own Mac, so you won’t see Safari results here, although I’ve run the tests on my friend’s MacBook with very similar hardware as my laptop has (Intel Core Duo 2ghz + 2 gigs of RAM), and it was faster even then Konqueror (no, it doesn’t mean his MacBook is faster then my laptop!!!! ;)).

I’ve run everything 3 times, here are average results in ms:

el.setStyle(‘color: red’)
})”` | 55.7 | 31 | 297 | 33.7 | | 4 | jQuery | “` erb $(‘td.content span.even’).before(‘text’) ”` | 382.7 | 177.3 | 373.7 | 205.3 | | Prototype | “` erb $$(‘td.content span.even’).each(function(el) { el.insert({before:‘text’}) }) ”` | 359 | 90.7 | 527 | 138.7 | | 5 | jQuery | “` erb$(‘td.content h3’).show()”` | 178.7 | 227.7 | 83.3 | 1161.7 | | Prototype | “` erb$$(‘td.content h3’).each(Element.show)”` | 38 | 21 | 250.7 | 19 | | 6 | jQuery | “` erb$(‘div.special’).hide()”` | 90 | 81.3 | 33.7 | 375.3 | | Prototype | “` erb$$(‘div.special’).each(Element.hide)”` | 18 | 7 | 73.3 | 12 | | 7 | jQuery | “` erb$(‘div.special, td.content .odd’).toggle()”` | 637.7 | 431.7 | 517 | 1360.3 | | Prototype | “` erb$$(‘div.special, td.content .odd’).each(Element.toggle)”` | 71 | 43.7 | 106.7 | 43 | | 8 | jQuery | “` erb$(‘span.odd’).remove()”` | 132.7 | 59.3 | 123.3 | 66.7 | | Prototype | “` erb$$(‘span.odd’).each(Element.remove)”` | 29 | 11.7 | 36.7 | 19.3 | | 9 | jQuery | “` erb$(‘#data p.lost:first’).html(‘gotcha!’)”` | 5 | 1.7 | 10 | 3.3 | | Prototype | “` erb$(‘data’).down(‘p.lost’).update(‘gotcha!’)”` | 11.7 | 2 | 10 | 7.3 |

Conclusion #2

Prototype was at least 2 times faster then jQuery in 15 cases, and jQuery was faster then Prototype in 8 cases. What library should I choose? In my case I will stick with Prototype, because it offers the same functionality as jQuery does + more and it’s faster. jQuery is probably better for projects where there’s a need for some fancy UI effects and that’s it, but it’s just an assumption, correct me if I’m wrong…