We're looking for a person or people to help audit MDN to find places we could speed up. Is this you or someone you know? Check out the RFP: https://mzl.la/2IHcMiE

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

See what it looks like from Firefox 52 onwards.

To open the debugger press the menu button ( new fx menu ), press "Developer", then select "Debugger". Or use the keyboard shortcut:

  • Control-Shift-S in Windows and Linux
  • Command-Option-S on a Mac

The Toolbox will appear at the bottom of the browser window, with the Debugger activated. Here's what it looks like when you first open it:


Document Tags and Contributors

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