UA Profiler and Google Chrome

September 9, 2008 6:18 pm | 5 Comments

The night before it launched, I sat down to analyze Google Chrome from a performance perspective – what good performance traits did it have and which ones was it missing? I couldn’t get to the internal download links and had to resign myself to waiting for the official launch the next day.

Or did I?

Instead of watching Season 2 of Dexter or finally finishing Thunderstruck, I stayed up late writing some tests that could automatically poke at Chrome to determine its performance personality. It worked great, and made me want to run the same analysis for other browsers, and open it up to the web community to measure any browser of interest. A week later, I’m happy to announce the release of UA Profiler.

UA Profiler looks at browser characteristics that make pages load faster, such as downloading scripts without blocking, max number of open connections, and support for “data:” urls. The tests run automatically – all you have to do is navigate to the test page from any browser with JavaScript support. The results are available to everyone, regardless of whether you’ve run the tests. See the FAQ for a description of each test and my list of caveats (additional tests that are needed, limited browser detection, etc.). Here’s the overall scores for some popular browsers.

Browser UA Profiler
Chrome 8/11
Firefox 2 7/11
Firefox 3 8/11
IE 6,7 4/11
IE 8 7/11
Opera 9.5 5/11
Safari 526 8/11

Getting back to where I started, let’s look at Chrome’s performance profile. It’s nice to see that Chrome is at the top right out of the shoot, having 8 of the 11 performance attributes tested, tied with Firefox 3 and Safari 526. The three performance features Chrome is missing are loading scripts and other resources in parallel, not blocking downloads when a stylesheet is followed by an inline script, and support for prefetch links. Looking at the Chrome user agent string we can see it’s based on Safari 525. If Chrome incorporates Safari 526 improvements, it’ll fix the most important performance trait – loading scripts in parallel. The detailed results show that Chrome has one improvement over Safari: caching redirects that have an expiration date in the future.

UA Profiler will continue to evolve. I have a handful of tests to add and there are several GUI improvements to be made. The main way it’ll grow is by people navigating to the tests with their own browsers, especially browsers that aren’t currently in the list. On each page there are links for contacting me about bugs, mistakes, and suggestions. I look forward to your feedback.

5 Responses to UA Profiler and Google Chrome

  1. Hi Steve,
    Great idea!

    I tried with Chrome, but I only get a maximum of 6 connections and not 60.

    Could this be related to the fact that I’m behind a proxy?


  2. Yes, most browsers have different limits for opening connections when you’re behind a proxy (see Roundup on Parallel Connections).

  3. Some tests results depends on browser configuration. For exemple with Firefox you can change the number of connections per host by editing advanced prefs.
    Thanks for your tests, they are pretty interesting.

  4. My thought is that most users don’t modify these settings. Therefore, by letting lots of people run the tests, the default settings will win out. I’ll add to the FAQ – the way the overall results are calculated is similar to a median – so outliers shouldn’t have much of an effect.

  5. there are so many advantages and features with Chrome, such as it’s speed, for example; now if only they would take care it’s flighty cookie management…