This page describes the JavaScript Debugger as it appears before Firefox 52.

See what it looks like from Firefox 52 onwards.

The JavaScript Debugger enables you to step through JavaScript code and examine or modify its state to help track down bugs.

You can use it to debug code running locally in Firefox or running remotely, for example in a Firefox OS device or Firefox on Android. See remote debugging to learn how to connect the debugger to a remote target.


User Interface Tour

To find your way around the debugger, here's a quick tour of the UI.


How to

To find out what you can do with the debugger, see the following how-to guides:


Reference

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 Contributors to this page: wbamberg
 Last updated by: wbamberg,