Development Blog

Firebug 1.13 alpha 5 has Firebug 1.13 alpha 5

Firebug 1.13a5 fixes 9 issues
Firebug 1.13a5 is compatible with Firefox 25-28


This version doesn’t introduce any new features. The entire team is now focusing and hardworking on adopting the new debugging API that shall represent the heart of the debugger in This work will be also included in alpha releases soon.


Please post feedback in the newsgroup.


Jan ‘Honza’ Odvarko


Firebug 1.13 alpha 4 has Firebug 1.13 alpha 4

Firebug 1.13a4 fixes 10 issues
Firebug 1.13a4 is compatible with Firefox 24-27

Some highlights from this release

  • Display registered Mutation Observers (issue 6740)

    The existing getEventListeners() command (see a Firebug tip) has been extended and it now displays also registered mutation observers for given element.

    Mutation Observers

    You can use this test page to try it yourself.

  • Searching by selector in the HTML panel (issue 6748)

    The search field inside the HTML panel now allows you to search for elements via CSS selectors. Just start typing a selector like body > div and the elements matching this selector will be matched. This new search feature got integrated with the already existing text search. So now you can search for both at once, text and CSS selectors. This makes it much easier to find the elements you’re searching for.


    HTML Search


    Again, you can use the test page to try it.



Post feedback in the newsgroup


Jan ‘Honza’ Odvarko


Firebug 1.12.4

Firebug team released Firebug 1.12.4. Another maintenance release fixing performance problem when switching Firefox tabs.


Firebug 1.12.4b1 has also been released to update users on AMO beta channel. This version is exactly the same as 1.12.4


Firebug 1.12.4 is compatible with Firefox 23 – 26

Firebug 1.12.4 fixes 1 issue.


This version introduces a workaround that solves Firefox tab switching and Firebug activation problem (see a platform bug). As a temporary measure, Firebug no longer pauses the debugger when switching tabs. This avoids long tab switching times (see issue 6086 for more details).

The entire problem will be properly fixed in the next major Firebug version that will be based on the new JavaScript Debugger API in Firefox.


Please post feedback in the newsgroup, thanks.

Jan ‘Honza’ Odvarko


Firebug 1.12.3

Firebug team released Firebug 1.12.3. Another maintenance release fixing a few minor issues.


Firebug 1.12.3b1 has also been released to update users on AMO beta channel. This version is exactly the same as 1.12.3


Firebug 1.12.3 is compatible with Firefox 23 – 26

Firebug 1.12.3 fixes 4 issues.


Some highlights from this release

There is a platform bug that slows down Firefox tab switching and Firebug activation. This bug has effect only if the Script panel is enabled. Since we can’t fix this problem Firebug is displaying a warning to notify users. The problem will be fixed in the next major Firebug release (Firebug will be using different debugging engine, see issue 6821 for more details).

The message is displayed on disabled Script panel and also in the Console panel.



This version also fixes one compatibility problem with FirePHP extension (issue 6803).

Please post feedback in the newsgroup, thanks.

Jan ‘Honza’ Odvarko


Firebug 1.13 alpha 3 has Firebug 1.13 alpha 3

Firebug 1.13a3 fixes 7 issues
Firebug 1.13a3 is compatible with Firefox 24-27

Some highlights from this release

  • JavaScript Array Inspector (issue 6773)
    It’s now possible to simply inspect large arrays logged into the Console panel. Large arrays are truncated in the Console panel, but if you click on the left or right bracket of the array (it’s a link now) you’ll be navigated into the DOM panel that allows you to fully inspect the array.

    You’ll be navigated to the DOM panel for full inspection after clicking.


  • console.table() & object logging (issue 6800)
    We have enhanced the console.table() API, and so it’s now possible to use it to log even generic objects. It can be useful in many cases. For example, you can log the DOM storage object.


Post feedback in the newsgroup


Jan ‘Honza’ Odvarko


Firebug 1.12.2

Firebug team released Firebug 1.12.2. This version represents a maintenance release. A few minor problem fixed, no new features.


Firebug 1.12.2 is compatible with Firefox 23 – 26

Firebug 1.12.2 fixes 8 issues.


Firebug 1.12.2b1 has also been released to update users on AMO beta channel. This version is exactly the same as 1.12.2


Bug fixes in this release are mostly related to the Console panel & logging, but there are also some fixes related to CSS inspection.


Please post feedback in the newsgroup, thanks.

Jan ‘Honza’ Odvarko


Firebug 1.13 alpha 2 has Firebug 1.13 alpha 2

Firebug 1.13a2 fixes 9 issues
Firebug 1.13a2 is compatible with Firefox 23-26

Some enhancements in this release

  • Issue 3195: Search field should display current tab
  • Issue 6334: Pressing the search field shortcut should select the previously entered search text
  • Issue 6746: Add a keyboard shortcut for creating a watch expression from the current selection
  • Issue 6760: Allow using the command line even when JavaScript is disabled


Post feedback in the newsgroup


Jan ‘Honza’ Odvarko


Firebug 1.13 alpha 1 has Firebug 1.13 alpha 1

Firebug 1.13a1 fixes 31 issues
Firebug 1.13a1 is compatible with Firefox 23-26

We are again hardworking on the next great Firebug version for now labeled 1.13. The team focuses on JSD2 adoption and our plan is to have it ready in this new version. We have great roadmap and if successful we want to call it 2.0 eventually.

Thanks to our awesome team we have already made several new features and improvements in 1.13 (while Firebug 1.12 has been out for couple of weeks only)!

Some highlights from this release

  • The Script panel displays a notification if the source cache limit has been exceeded (issue 4906)You can use the Preferences button to change the limit. Browser restart is not needed after limit modification, just reload the page to get full source.script-cachelimit


  • Quick Info Box for elements can be pinned (issue 5720)Note that there are two buttons at the top right corner. One for pinning the box, so it stays displayed all the time and one for closing it.quick-info-box

    Read more about the Quick Info Box on our wiki.


  • Headers in net requests are collapsible (issue 4930)The Net panel has also been improved. Sections with HTTP headers (Response, Request and Cached Headers) are now collapsible and the state is preserved across Firefox restarts. So those headers, in which you are not interested don’t take space


  • Better way to add a new element attribute (issue 6661)We have improved the way how HTML attributes can be added into elements. Check out the next set of screenshots.html-panel1

    Hover mouse cursor over the closing arrow bracket of an element you want to add a new attribute to. See, the cursor changes its shape into a hand.

    Click on the closing tag to open an inline editor and start typing an attribute name.


    The rest works as usual. After you typed the name press the tab key and type the attribute value.



There is a lot more fixed in this version and you can check out our issue list.

Stay tuned and post feedback in the newsgroup


Jan ‘Honza’ Odvarko


Firebug 1.12.1

Firebug team released Firebug 1.12.1. This is a follow up release based on feedback we have collected since releasing 1.12.0

Firebug 1.12.1 fixes 6 issues.

Note that Firebug 1.12.1b1 has also been released to update also users on AMO beta channel. This version is the same as 1.12.1


Some highlights from this release:

  • The problem with missing Firebug icons reported by some users is fixed (issue 6689).
  • It is possible to get rid of the Clear Activation List confirmation dialog (issue 6694)
  • There is a new preference extensions.firebug.console.groupLogMessages that allows to disable console message grouping (issue 6703)


Please post feedback in the newsgroup, thanks.

Jan ‘Honza’ Odvarko

Firebug 1.12.0

Firebug Working Group is proud to announce a new Firebug version!
Firebug 1.12.0 is now available for download.

Firebug 1.12.0b7 version has been also released to updated beta channel on AMO. This version is the same as Firebug 1.12.0

  • Firebug 1.12 is compatible with Firefox 23 – 26

Firebug 1.12 fixes 4 issues.


Firebug team has been working hard on this version. We have fixed ~160 issues, released 8 alphas and 7 betas, implemented 50 more automated tests (362 in total), had 79 online meetings and answered many Firebug related questions on our newsgroup.


See list of contributors who helped with the release.

  • Jan Odvarko
  • Sebastian Zartner
  • Simon Lindholm
  • Farshid Beheshti
  • Steven Roussey
  • Florent Fayolle
  • Awad Mackie
  • Belakhdar Abdeldjalil
  • Thomas Andersen
  • Hisateru Tanaka


New Features

Here is a short list of new features introduced in this version. You can also read detailed description with screenshots.

  • Copy CSS Properties
  • New Net Panel Filters
  • Filter for DOM Events Log
  • Autocompletion Popup Improved
  • Use in Command Line
  • Group Console Messages
  • Better Infotip for HTTP Request Timings
  • Multiple Filters for Console & Net Panel
  • Toggle Visibility of Side Panels
  • Store the result of the last command line evaluation in $_
  • New command: getEventListeners()
  • Copy as cURL
  • Precision for Console API %f log pattern
  • Show/hide stack arguments
  • CSS Panel Improvements


Get Involved

There are several ways how to help us.


Firebug Extensions

We have also spent time testing some of the existing Firebug extensions.
Here is a list of those that passed our review and work with Firebug 1.12.

  • Console Export Export data from the Console panel
  • CSS Usage See what CSS rules and properties are actually used in your app.
  • Dojo Firebug Extension Support for Dojo based app debugging.
  • Firebug Autocompleter Autocompleter now available in Firebug Command Editor.
  • Firediff Additional insight into the changes that are being made to the components of the page
  • FireFile FireFile is a Firebug extension to save CSS files edited with Firebug to your web server
  • Firefinder find HTML elements matching chosen CSS selector(s) or XPath expression quickly.
  • Fireflow Provides method call logs in a tree format.
  • FireLogger Logging support for web developers (PHP, Python, ColdFusion) (see also this post)
  • FirePath adds a development tool to edit, inspect and generate XPath 1.0 expressions and CSS 3 selectors
  • FirePHP FirePHP enables you to print to your Firebug Console using a simple PHP function call and a lot more.
  • FirePicker Adds color picker to Firebug’s inline CSS editor. (see also this post)
  • FireQuery Adds a collection of jQuery-related enhancements to Firebug. Recommended for all jQuery developers. (see also this post)
  • FireRainbow Brings Javascript syntax highlighting to Firebug.
  • FireStorage Plus! Is an extra panel to Firebug for displaying and manipulating the web storage containers such as localStorage and sessionStorage. (see also this post)
  • Illuminations for Developers is a tool to help you develop web applications by investing Firebug with the knowledge of your JavaScript framework and your workflow with it.
  • Javascript Deminifier Deminify javascript before it is downloaded.
  • Backbone-Eye Understand Backbone application behavior without debugging JavaScript.

We don’t have enough time to test all of the existing extensions, it’s mostly up to extensions authors.
But you can always see the complete list.


Firebug Lite

Firebug Lite is lightweight version of Firebug that does implement only a subset of features (mainly missing the Script and Net panel). It’s implemented as pure web application and running in all major browser. Useful especially for debugging on mobile devices with bigger screens (e.g. iPad). Firebug Lite is also maintained by Firebug Working Group and you can read more about how to start with Firebug Lite.


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Post feedback in the newsgroup


Jan ‘Honza’ Odvarko