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The Firebug Tracing Console (short FBTrace) is used for debugging Firebug and Firebug extensions. It logs all Firebug activities and thereby helps tracking down errors inside the source code.

Firebug Versions

First of all see how Tracing Console works with different Firebug versions.

  • Any Firebug release with 'X' in the label e.g. 1.7X has the Trace Console (aka FBTrace) built in.
  • For final releases 1.6 and 1.7 (no 'X'), you need to install a simple extension that brings back the menu item.


  • The Trace Console is entirely removed from Firebug core since 1.8a1. We are not planning to release 'X' versions any more. You need to install FBTrace extension in order to have the console.



Until Firebug 1.7 FBTrace was bundled together with its alpha and beta versions. To be able to inspect the logs even in the case Firebug is broken (e. g. it doesn't even load itself) and to make the release process easier for Firebug 1.8 FBTrace was extracted from the Firebug source and is now available as an independent extension. For more information about this step please read the news group thread about FBTrace as well as the blog entry to Firebug 1.8a1.

From XPI

The simplest way how to install FBTrace extension is to use an XPI we regularly build from the source. Check releases directory for the latest version.

From Source

You can get the FBTrace source using a Subversion client. To install FBTrace please follow the description of building Firebug from source or place a file named fbtrace@getfirebug.com containing the path to the source code in your Firefox profile directory (for more info on how to do this please read the steps to create a Firefox extension proxy file).

How to open the console

After you installed FBTrace you have following possibilities to start it:


Firebug allows opening of the console from Firebug Icon Menu

  • Firebug Icon Menu -> Open Tracing
  • Firebug Icon Menu -> Options -> Always Open Tracing


If you want to open the console for Firebug automatically after restart you need to set following preference to true:



  • Chromebug Tools -> Open Chromebug Tracing Console


If you want to open the console for Chromebug automatically after restart you need to set following preference to true:


Tracing from your own extension

You can use the console also from your own extension - Firebug doesn't need to be even installed. All you need is the FBTrace extension.

  • Your extension should create a new preference:
pref("extensions.firebug.DBG_MYEXT", false);
  • extensions.firebug.DBG_ prefix is mandatory.
  • As soon as the preference exists you should see a new option MYEXT in the Tracing Console.
  • Get the tracing service in your code.
var FBTrace = traceConsoleService.getTracer("extensions.firebug");

... and create a log:

    FBTrace.sysout(string, object);