What is a good Javascript debugging tool?

Question

Haven\'t touch javascript for 3 years. Just got a javascript project and wanted to know any new ways or tools emerged these years to debug javascript? I used alert 3 years

Answer 1

I argue to use build-in browser debugger for performance reason. Firefox and Chrome one are good enough.

They allow browse DOM, show dynamically generated sources, show network activity, profile JS, etc.

But don't miss printf-approach with:

console.log("this is %o, event is %o, host is %s", this, e, location.host);

and:

console.log("%s", new Error().stack);