Thomas Fuchs
Hi, I'm Thomas Fuchs. I'm the author of Zepto.js, of, and I'm a Ruby on Rails core alumnus. With Amy Hoy I'm building cheerful software, like Freckle Time Tracking and Every Time Zone and write books like
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6 easy things you can do to improve your JavaScript runtime performance

November 8th, 2009

Here are the slides from my “Extreme JavaScript Performance” talk that I gave at 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.

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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.