How to View JavaScript Errors in Firefox


Mozilla Firefox contains an error console that displays errors, warnings and other messages from the JavaScript and cascading style sheet files on Web pages and installed add-ons. Access to the error console is disabled by default starting with Firefox 4. You can view JavaScript errors by enabling access to the error console and filtering out the warnings and other messages. The console only shows errors for your current Firefox session.

  • Type "About:config" into the address bar near the top of the Firefox window, and press "Enter."

  • Click the "I'll Be Careful, I Promise" button on the warning page that appears.

  • Type "Errorconsole" into the filter box at the top of the page.

  • Double-click the "devtools.errorconsole.enabled" preference to enable it.

  • Close all open Firefox windows, and re-open Firefox.

  • Click the "Firefox" menu button, hover the mouse cursor over "Web Developer" in the menu, and click "Error Console."

  • Click the "Errors" button at the top of the error console window to show only errors, not warnings or messages.

  • Navigate to the Web page with the errors, and read them from the error console window.

Tips & Warnings

  • Click the "Tools" menu if you don't see the "Firefox" menu button.
  • The About:config page contains a variety of options users shouldn't modify; be careful when using it.


Promoted By Zergnet


You May Also Like

  • How to Debug JavaScript for Firefox

    JavaScript errors and bottlenecks can stop beautiful code in its tracks. However, debugging JavaScript in Mozilla Firefox can be greatly expedited by...

  • How to Enable JavaScript Errors in IE

    The "Disable Script Debugging (Other)" option on the advanced pane applies to other applications that embed Internet Explorer to show Web pages,...

Related Searches

Is DIY in your DNA? Become part of our maker community.
Submit Your Work!