What is the best tool to benchmark my JavaScript?

Question

I'm currently working on a JavaScript tool that, during the course of its execution, will ultimately traverse each node in the DOM. Because this has potential to be a very expensive task, I'd like to benchmark the performance of this script.

What's the best, free tool for benchmarking a script such as this across the major browsers? Ideally, I'd like the tool (or set of tools, even):

• **To generate some form of report based on the results of the test.** It can be as simple as a table showing execution times, or as complex as generating some form of a chart. Either way is fine.
• **To be free.** it's not that I don't believe in paying for software, it's just that I don't have a major need for a tool like this in my typical day-to-day tasks.

If possible, I'd also like the tool to generate varying levels of complex pages so that I can stress test a set of DOMs. This isn't a necessity - if I need to do so, I can write one myself; however, I'd figure I'd poll the community first to see if something already exists.

Answer 1

Jeff posted The great browser javascript shutdown

SunSpider JavaScript Benchmark

But i wonder where the download link is ;)

Answer 2

I believe Firebug includes profiling of JS code. Of course, it's not available in all the major browsers--only Firefox.

Answer 3

Firebug does include JS profiling, and it is probably the best out there. While I've had problems with Firebug's debugger, its profiler is currently top-of-the-line. Venkman is also an older JS debugger/profiler for Firefox, just in case you run into Firebug issues.

Using these tools should get you just about all the profiling you need across all browsers even though you'll only be monitoring Firefox. If you truly need to get down to dirty details of IE profiling and the like, there are a number of tools online that inject profiling calls into your javascript to help monitor all profiler-lacking browsers....but even to a JS performance nazi like me, this seems unnecessary.

Note: A new, very promising IE8 JS profiler has recently been announced: http://blogs.msdn.com/ie/archive/2008/09/11/introducing-the-ie8-developer-tools-jscript-profiler.aspx.

Answer 4

In FireBug and FireBug Lite you can call the console.time() and console.timeEnd() methods in your code to start and end a timer around a particular piece of code. The Profiler tool in FireBug will measure how long each function takes. I've used it a lot to narrow down which lines of a particularly slow function are causing the slowdown

Answer 5

For JavaScript, XmlHttpRequest, DOM Access, Rendering Times and Network traffic for IE6, 7 & 8 you can use the free dynaTrace AJAX Edition