Ajax Performance

Low Level JS Performance Analysis

Bob Buffone, of Nexaweb, Apache XAP, jsLex, and RockStarApps.com (he’s busy), spoke on “Performance Tuning Your Ajax Application” last week at AjaxWorld. Fortunately for those of us who regrettably missed the show, Bob has written a companion piece to the presentation, covering many of his findings. He also posted a page with the client side performance code, so you can collect the metrics on your own browsers and dig in for yourself.

Bob compares different low level techniques for accomplishing common actions in JavaScript, such as using ‘for in’ versus C-style for loops, and he ranks this performance across browsers. In the process, he stumbled over a number of different performance anomalies and performance cliffs in his testing, and he has kindly summarized those as well. This is really cool data, fresh from the trenches, and great analysis for any developer who is focused on client side performance.

Also, Bob takes a moment at the end of the article to agree with my criticisms of Joel. Lesson to my readers: if you post an article agreeing with me about something, there’s a good chance I will link back to you