6 easy things you can do to improve your JavaScript runtime performance

Here are the slides from my “Extreme JavaScript Performance” talk that I gave at JSConf.eu on November 7 in Berlin.

I’m talking about 6 easy things you can do to improve your JavaScript runtime performance, ranging from simple things (function inlining) to some quite surprising findings on how JavaScript engines deal with loops.

There’s benchmarks for the four most common JavaScript engines, SpiderMonkey (Firefox 3.5), JavaScriptCore (Safari 4), JScript (Internet Explorer 8) and V8 (Google Chrome).

Be cautious however! Only do these optimizations if you have to, and, please, for the love of all the JavaScript gods, do not, ever, optimize prematurely. 🙂

Finally, here’s a PDF (750k) of the slides, if you want to read it offline and/or in dead tree form, and there’s a Github Gist of the example code, so you can run it yourself.

I welcome any comments, and findings you might have had with optimizing your JavaScript code.