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The Browser Console is replacing the Error Console

Hello Mozillians!

Today's Firefox Nightly (May 29, 2013) no longer has the Error Console enabled by default. It has been replaced by the Browser Console which shows all of the same errors, warnings and messages as the Error Console and more: network logging and window.console API logging from all content and chrome windows - including extensions! It also has a better UI, you can filter messages, evaluate JS with chrome privileges and inspect objects.

If you find missing messages, please file bugs as soon as possible in the "Developer Tools: Console" component. Thank you!

The Browser Console shares the same code with the Web Console. This means you will get all of the improvements we are working on - we are gearing up for a console output UI rewrite.

If you want to enable the Error Console you can change the devtools.errorconsole.enabled option to true from about:config.

Pro tip: in your Firefox chrome code (including extensions) you can do:

console.log("hello", yourObject);

The above code will output to the Browser Console if you have it open - you can inspect objects, print stack traces (console.trace()) and do a bit of timing (console.time("foo") / console.timeEnd("foo")).

Have fun!

Update: these changes should have no impact in Thunderbird, XULRunner or any other applications. Currently the changes are limited to hiding the Error Console menu item from Firefox by default, and the Ctrl/Cmd-Shift-J keyboard shortcut now opens the Browser Console instead of the Error Console.