Archive for the 'Uncategorized' Category

Firebug 2.0.19

Wednesday, March 1st, 2017

The Firebug team released Firebug 2.0.19. This is a maintenance release ensuring compatibility with latest Firefox releases.


The beta channel on AMO is also updated.

Firebug 2.0.19 is compatible with Firefox 30 – 54

Firebug 2.0.19 fixes issue 8077.

You might also want to read about Unifying Firebug & Firefox DevTools.


Please post feedback in the newsgroup, thanks.

Jan ‘Honza’ Odvarko


Firebug 1.13 alpha 10

Friday, March 21st, 2014 has Firebug 1.13 alpha 10


Firebug 1.13a10 fixes 12 issues
Firebug 1.13a10 is compatible with Firefox 28-31


This version is released mainly for Firefox Nightly users fixing one compatibility issue.
We have been working hard over last 10 alphas and except of fixing regular issues we have been also adopting the new JavaScript Debugger API in Firefox known as JSD2 (issue 5421 in our issue list).


This adoption has been done and our entire test suite composed of about 400 automated tests finally passed and all tests are green (issue 7166). Since we have done a lot of changes and also the Firebug UI went through a great face lift, we are going to call the next version Firebug 2.0 alpha 1! (will be available next week)


Here is a sneak peak of how the new UI looks like compared with the current one:


Firebug 1.12 (current release) Firebug 2.0 (next alpha)

Stay tuned!


Please post feedback in the newsgroup.


Jan ‘Honza’ Odvarko


Firebug 1.10b3

Friday, July 6th, 2012

Firebug 1.10 beta 3 has been released.

Firebug 1.10b3 fixes 10 issues.

There are couple of changes we would like to highlight in this release.

Net Panel: requests coming from Back-forward cache

Visual design of HTTP responses coming from BFCache has been changed and so, it should be easier to distinguish these special requests from other requests (Issue 3757).

First, let’s see requests coming from standard browser cache.

  • Every request coming from the browser cache is grayed out and the Status column says 304 Not Modified.
  • The screenshot above displays 8 requests coming from the browser cache.

Let’s see how requests coming from the BFCache (specific for Firefox browser) are displayed.

  • Every request coming from BFCache is grayed out with squared background.
  • The status column says 200 OK (BFCache)
  • The screenshot above displays 8 requests coming from the BFCache.
  • Note that the Remote IP column is empty since there was no communication with server at all. These requests come directly from the BFCache without asking the server.

In order to see requests coming from BFCache you need to check Show BFCache Responses (false by default) option in Net panel’s option menu (the small black triangle next to the panel name).

Command Line: help

There is a fresh new command help available on Firebug’s command line (Issue 5142).

If you want to learn about all Firebug command line API, just type help to print list of all available commands with description.

Every command name (green color) is a link that navigates you to Firebug wiki for more information about the specific command.

Please post feedback in the newsgroup, thanks.

Jan ‘Honza’ Odvarko

Firebug Lite 1.3.1

Thursday, September 9th, 2010

As John J. Barton told in a previous post, I’m working now on Firebug Lite. Today I’m bringing a good news: Firebug Lite 1.3.1 is out!

Compared to Firebug 1.3.0, the 1.3.1 version is more stable, faster and has more cool features. All known defects were fixed (with the exception of one which was partially fixed), considerable performances improvements were made, and the two most popular Firebug Lite features (CSS editing and XHR inspection) received a lot of improvements.

Regarding CSS editing we could highlight: more accurate auto-completions, able to edit element styles via content menu (right-click the CSS/Style Panels), more accurate calculation of specificity of CSS rules, use of double-click to add a new CSS rule (instead of mouse-down as it was being handled in 1.3.0). Regarding the XHR inspection we could highlight: a few important bugs were fixed that could potentially break web applications using XHR when Firebug Lite was enabled, and last but not least it was added the cool JSON, XML and HTML viewers which means that now you can easily analyze JSON, XML and HTML data being sent (request) or returned (response) via XHR. Here’s the JSON viewer in action:

Give it a try! Go to and choose your favorite flavor of Firebug Lite. If you don’t like adventures, pick the stable channel. If you are the curious geek kind and wanna debug Firebug Lite, use the debug channel. If you are avant-guard and like brand new stuff, the beta channel is your choice. But if you are a wild adventurer and fear no bugs and raw art, I dare you use the developer channel.

You are a Chrome lover? There are some special flavors for you too! You probably already heard about the Firebug Lite for Google Chrome extension, which is basically the “stable channel with sugar”. But now we have also a “beta channel with sugar”: Firebug Lite Beta for Google Chrome.

Here is the list of 13 issues fixed in 1.3.1:

  • Issue 3272: Install Google Chrome extension results in a 404 error
  • Issue 3384: Just two inadvertent globals across the Firebug Lite files
  • Issue 3318: Firebug Lite dies if you hide the UI when the large command line is open
  • Issue 3181: Firebug Lite Missing XHR methods/properties
  • Issue 3262: CSS specificity is not being calculated properly.
  • Issue 3038: Empty (null) styles when adding CSS styles in Firebug Lite
  • Issue 3224: Firebug Lite shows error when trying to read some external stylesheets
  • Issue 3181: Missing XHR methods/properties
  • Issue 2958: Unable to add CSS to an element that has no style rules
  • Issue 3165: Styling problem with nested expandable groups
  • Issue 3178: Bookmarklet does not support XML+XSLT documents
  • Issue 3118: Long lines in XHR response
  • Issue 2981: Switching from CSS tab and back causes an error

If you want a more detailed list of changes check our changelog.

Pedro Simonetti

Please post feedback in the newsgroup, thanks.

What’s this other crank for?

Sunday, March 21st, 2010

During the demo of Charle’s Babbage’s Difference Engine #2 at the Computer History Museum, a docent turns a large hand crank to compute values of a 7th order polynomial by divided differences and print the results. After the demo I noticed another crank on the opposite end of the machine, awkwardly positioned near the ground:

Debug crank for Charle's Babbage's Difference Engine #2.

jjb: “What’s this other crank for?”

docent: “We use that to debug the machine.”

jjb: “(D’oh!)”.

A clutch on the drive line connecting the operator crank to the printer allows the printer and calculator to be decoupled.  The secondary crank can then operate the printer independent of the calculator. Classic divide and conquer debugging.


For followup comments, please use the newgroup.

Firebug 1.5b5

Wednesday, November 25th, 2009 has Firebug 1.5X.0b5. We are just fixing bugs now, and filing off the rougher edges of our new features. All tests pass on Firefox 3.5.5. One test fails on Firefox 3.6, due to bugzilla bug 486506. Two tests fail on Firefox 3.7, the same 486506 bug and one where we need to change the test to match a new error message.

  • Update locale zh-CN, vi-VN, pl-PL, ru-RU
  • Issue 2508: Potential translation issues in Firebug 1.5b3
  • Issue 2501: Firebug 1.5b4 breaks some ajax requests
  • Issue 2499: Show HTTP protocol version on the Net tab
  • Issue 2496: build.xml jsdoc fix for 1.5
  • Issue 2491: “Break On Errors” acts more like “Break On Next Error”
  • Issue 2479: Net panel doesn’t show timed out requests
  • Issue 2462: The firebug console still shows the xhr in progress if you abort it (via request.abort())
  • Issue 2452: Console shows regular expression error when attempting to search
  • Issue 1953: No Layout Information for SVG Elements
  • Issue 1111: Copy Location With Parameters doesn’t copy the correct parameters
  • Issue 2510: Console and watch returns undefined for falsy values when debugger is stopped
  • Issue 2520: The top offset and left offset values in the Layout tab in the HTML panel are incorrect
  • Issue 2511: The +/- in DOM panel does nothing when next to long strings


Followup on the newsgroup please.

Javascript Quiz

Thursday, October 8th, 2009

Ok you Javascript hot shots,  here is a two question quiz:

  1. What does the error message “XML filter is applied to non-XML value {}” mean?
  2. What does this Javascript statement do: window.("bar"); ?

For the first question you may use Google to search; for the second question you may use the Firebug command line. If you find the answer don’t spoil the quiz for others ;-).


Followups on the newsgroup please.

Firebug 1.5a24

Thursday, September 10th, 2009 has Firebug 1.5X.0a24. All tests pass on Firefox 3.5.2; one failure on Firefox 3.7 nightly that we are looking into.

This version introduces support for the network activity observer added by Firefox in bugzilla 488270. This will lead to much more accurate network event timing, but it requires Firefox 3.7.

Also included is an early version of Honza’s “Break on Mutate”, part of our effort to implement “break-on” functions for all of the panels.  You can get early peak by trying the test page (don’t forget to reload).

  • Issue 2280: Problem with xpi built with the ant script
  • Issue 2279: Error Breakpoint can’t be toggled off.
  • Issue 2288: FB hangs and raises CPU to 100% due to getStyleSheetByHref
  • Issue 2281: Breakpoints and jQuery 1.3.2 problem
  • Issue 2187: firebug causes memory leaks


Please post followups to the newsgroup.

Firebug 1.4.1

Monday, July 27th, 2009 has Firebug 1.4.1, an update of Firebug 1.4 with many bug fixes. While we don’t have the resources to create a proper change log for the complete bug list, a close approximation include the fixes on the 1.5 branch starting with 1.5a16 and including 1.5a20. Those changes are described in these blog posts:

We expect this to be the last bug fix release of 1.4. We may release addition localizations or locale updates as they become available.


Please post followups to the newsgroup.

Firebug 1.5a17

Monday, July 20th, 2009 has Firebug 1.5a17, a preview of fixes that will appear in Firebug 1.4.1

  • Issue 1931: Inspect causes duplicate HTTP request
  • Issue 2042: “Reload to activate window console” doesn’t go away
  • Issue 2049: Firebug opens on mouse down (it does not wait for mouse up)
  • Issue 2054: update close icons
  • New locale Russian ru-RU

This version also prevents Firebug from opening “system” URLs, like  about:blank, about:config etc. We may be able to relax this later, but for now the restriction is needed for FBtest 1483 to pass. Every page load seems to begin with “about:blank” being loaded,  and when system URLs are allowed, Firebug gets distracted by that extra window.


Please post followups to the newsgroup.