What tool do you use for debugging Javascript? [closed]

Question

I've notices I'm not capable to debug correctly js. I'm only using alert() as a spread sentences technique but I need something better. So... which tool do you use?

Answer 1

For Firefox Firebug it's the best, has a lot of useful features, the Console API is great, you can log, make assertions, profiling, timing and much more.

For IE, the Developer Tools of IE 8 is better than nothing, for earlier versions of IE, try the Developer Toolbar.

For Chrome and Safari, check the WebKit inspector and debugging tools.