Help us to make Firefox 4 better: How to open a bug

If you run Firefox Beta or Firefox nightlies, you will probably run into some issues. Reporting these bugs and crashes will help us to make sure the user experience is better for all Firefox 4 users.

Marcia Knous is part of the Firefox QA team. Because reporting a good bug is not that easy but extremely important, Marcia explains us how to file a bug correctly:

Starting out with bugzilla

So you found a bug – To make sure this bug will be considered, you need to create an entry into our bug database: bugzilla. And as a good first step into Bugzilla, I strongly suggest you start by watching this video:

Bugzilla For Humansby Johnathan Nightingale

You can also use the Bugzilla Guided Tour which is a step by step Guide to filing a bug.

Reporting a bug

After you have a better grasp of how to file a bug, it’s time to gather the data we will need to enter the bug into Bugzilla.

As we are web developers, experimenting with pre-release of Firefox and experimenting with new standards, you can be faced with crashes and incorrect behavior.

Search Bugzilla for the bug first

Although you may not find it, this will at least try to prevent duplicate bugs from being filed. Also consult the Bugs filed Today link to see if someone beat you to it!  You can also add ”’DUPEME”’ to the status whiteboard if you are unsure, and a query will pick that up so we can check to see if it a dupe.

It’s a crash? Go get the Crash Information

We are keeping a stack trace of crashes. You can see these traces
if you type “about:crashes” in the URL bar

Locate the crash stack – the latest one is the first of the list – it will look something like [@ libgcrypt.11.dylib@0xc21a ].

Add it in that exact form in the Summary field. An example would be: Crash in [@ libgcrypt.11.dylib@0xc21a ] while loading Zimbra calendar.

Paste the report ID link in the Bug Summary section.  (This is important so the crash shows up in with a bug associated to it). A report ID will look like this: bp-68a686c4-9a15-4326-a812-c8b772100812

Have a Layout bug or Reproducible Crash? Add a Testcase

As you can imagine, it’s way easier to work on a bug with a testcase.

You can attach the testcase under the attachment section. And in this case, add the “testcase” keyword to the bug

Make the Bug Summary useful

Which version of Firefox do you run? To know that, we
need the “Build ID”. Click “help” then “about Firefox/Minefield”.
It should look like this:

Mozilla/5.0 (X11; Linux i686; rv:2.0b4pre) Gecko/20100817 Minefield/4.0b4pre

Also, include a set of Steps to Reproduce the bug. Please be as detailed as possible. For example, you should include whether you used the mouse or keyboard to initiate a command.  Mozilla Developer Bug Writing Guidelines has many other suggestions as to what you should include in the bug.

These Bug Guidelines will take you through a tour of some of the other information that needs to be included, such as Product, Component, Version, Hardware/OS, and Keywords.

(Tip: As a web developer, you probably want to open a bug into the Product “Core”. Then, choose the Component depending on the bug.)

Thank you!!!

We know how difficult it can be to open a bug. Opening a bug is extremely useful. So thank you so much to taking the time to make Firefox better!

About Paul Rouget

Paul is a Firefox developer.

More articles by Paul Rouget…


  1. Dan

    The video is looking at Bugzilla using the non-default skin (Dusk) so most new users won’t see it like that (they’ll see Classic). Perhaps the site default should be changed.

    August 20th, 2010 at 14:27

  2. Mike Parks

    I have to stay on FF 3.5.11 because if I try anything higher, I lose my Curser
    trying to send text on “Community Feedback”

    August 20th, 2010 at 18:34

  3. ex700

    Man the only thing i dont like about updating is that it almost always breaks my roboform addon. everything else seems fine sometimes is a memory hog but i think that might just me because of my slow computer.

    September 2nd, 2010 at 19:08

    1. Ethan


      With how fast they release updates and fixes to their browser integration you’d swear there was magic involved.

      September 9th, 2010 at 06:01

  4. John Beattie

    Reporting a bug officially sure seems complicated. So I’ll just report it here, is that okay, since it’s quite simple to describe.

    On my Mac 10.4.11 using Firefox 3.6.10, in Google advanced search if I choose 100 results it always still only shows 10 results.

    That’s it! That’s the bug.

    I don’t think Firefox 3.6.9 had this bug, although I’m not sure. The bug has only cropped up fairly recently.

    The bug does not happen in Safari 4.0.3, Opera 9.51, or Netscape 7.2. In all those browsers, the 100 results show up in Google advanced search just as requested.

    October 3rd, 2010 at 10:06

  5. Mike

    I am having problems with both 3.5.14 & 3.6.11, the curser comes & goes & also the text you cannot see it when typing. I am having a job typing this out.
    I find now that I can keep typing and after awhile the text, appears, but you cannot see it when typing. When you stop typing the Curser keeps blinking
    on & off. Sometimes it stays off for 3 sec’s & sometimes longer. I tried a diff.
    browser like IE & everything is normal, & also everything is very slow, It’s just
    like I’m back on dial-up, Sincerely, Mike

    October 24th, 2010 at 15:12

  6. Mike

    Sorry forgot, I am running Windows XP PRO Mike

    October 24th, 2010 at 15:20

  7. Eric Kolotyluk

    The most annoying thing about Firefox 4 is that it allows malicious web sites to open a modal dialog asking the user to run/install some software. Because this is a modal dialog, the entire UI of Firefox is frozen out, so there is no way to remove this dialog. If you simply close the dialog window, it pops up again immediately.

    Under no circumstances ever should Firefox allow a modal dialog!

    October 31st, 2010 at 13:48

  8. Eric Kolotyluk

    OK, so I tried to search to a bug similar to mine, but could not. Then I entered a new bug and got an e-mail that it was a duplicate. Fair enough. So then I try to read the original but. It was reported 10 years ago, has hundreds of comments, and has still not been fixed – so I point this out and ask if anyone is going to fix. Then I get back a nice summary of the situation, albeit a little sarcastic. So I thank them for their summary.

    A few minutes later I get a personal e-mail from someone telling me “Please stop polluting the workspace for Firefox development with advocacy comments or requests for status updates. Think of Bugzilla as a very busy developer’s desk and work environment. Those kinds of interruptions only slow the process of getting the work done.”

    Well that’s the last time I ever try to use bugzilla to report a Firefox problem. I don’t need sarcasm and intolerance when I am simply trying to make Firefox better – and they obviously don’t need my kind of “pollution.”

    Chrome is now better than Firefox in many respects, so I now wish Firefox a long and happy obscurity.

    November 1st, 2010 at 08:07

    1. Justo Negron

      So as I men! I will delete mozilla from my computer, and use Chrome! Sometimes when you try and do some good, these developers, just jump, and stomp you out! Like we want to tell them how to do their job… thats not the point at all… we just want Mozilla to be the best free browser in the market!

      March 31st, 2011 at 15:34

  9. Ichabod

    Why have the taken away the history button? The one where you can decide what page you want to go back to if you are stuck on a page that wont let you leave the page.

    November 12th, 2010 at 02:24

  10. bugsy

    Bug report: Firefox 3.0.19
    I right-clicked a history sub-folder and selected Cut, then my *whole* history vanished for ever. I tried Paste into a new folder or a text file, but it only pasted the folder name. On restart still 0 history. This was in the sidebar, not the manager.

    February 3rd, 2011 at 14:50

  11. annetter88

    Firefox 4: Google search is autocompleting but not allowing selection of the suggestions for searching.

    March 28th, 2011 at 10:42

  12. Justo Negron

    I recently started using the firefox version 4.0. This browser have major bugs. Im no expert in the matter, so Im going to explain them as I see them.

    1. It crash when you are using stylish.
    2. It dont let you load the internet radio stations, I have to use other browser for that.
    3. It frizzes up when you are using facebook.
    4. Games are to slow, when played.
    5. Problems loading pages, even the home pages, which for me is the google page.
    6. Cant load some pages, like the ones that are reported as malware pages (but are not), when you have mcafee malware protection.

    These are the most irritating ones… there are some more, but I need some technical expertise to explain them to you, and I dont have that expertise.

    March 31st, 2011 at 15:29

  13. Patricia013

    I just upgraded to Firefox 4.0 and immediately saw a bug. I’m not all that computer literate so I’ll report it here. At times one of my bookmark entries shows up in my taskbar and won’t leave until I click on it. It seems to be fluctuating between two separate bookmarks and removing them doesn’t matter it just picks up two more. They should make reporting Firefox bugs easier – we’re not all geeks.

    April 2nd, 2011 at 11:06

  14. Amir P

    We are working with H2 web console for accessing an Oracle Database with lots of schemas.
    Well it’s a heavy AJAX page.
    Firefox 3.0.x and 3.5.x just did well with it, but Firefox 4 stops responsing so often

    April 21st, 2011 at 14:32

  15. Alex

    I cant use the tab shortcuts like ctrl + 1, ctrl + 2, ctrl + forward when im on a YouTube tab. It does work at any other page. Please fix it.

    May 7th, 2011 at 02:36

  16. Greg Simkins

    I could not use Firefox 4.01 on my MacBook Air. It locked up constantly. I had to force quit, even though OS X didn’t recognize that it was locked up.
    I went back to Firefix 3.6.13. Luckily I still had the image in my download folder.

    May 13th, 2011 at 08:03

  17. Glen

    Firefox 4 is probably the most un-successful “new” Product since the “New Coke Formula” and the Ford Edsel!

    It has been a DISASTER for me and many I know.

    The cgi order form button on my own website does not work for anyone using Firefox 4.

    Darn annoying and folks take ages ordering, press the button, assume it has gone though, and sadly nothing reaches me. Annoyed clients and large loss of money for me.

    Tonight I tried to book a complicated multi city International itinerary on United Airlines site. Spent 30 minutes getting it right, went right to “Purchase” page and the SAME issue ….. click “BUY” button – and ZILCH.

    Removed Firefox 4, did it all again, and worked fine using Firefox 3.6.

    Thanks Firefox for wasting a good hour of my time tonight.

    Tech boards all over the globe have reported these glitches for quite a while on order buttons, and the geeks there seem to be all asleep.

    Bill Gates must be laughing his head off – and you now have Microsoft’s VISTA on your hands.

    They did not fix that either, and folks still use it as an example of an “UPDATE” that should never have been released as the bugs were never Beta Tested out.


    June 7th, 2011 at 10:23

    1. louisremi

      You should file a bug in if you think the bug is on our side.
      We carefully test our browsers before releasing them. When there are problems with particular websites, it sometimes has to do with the way those websites are built.

      June 8th, 2011 at 05:53

  18. ozstamps

    Tech sites worldwide are reporting this bad bug on “ORDER” buttons.

    If you think has an issue with YOUR software – well you are totally entitled to your view.

    Firefox 3 worked perfectly on United after I removed #4, and that new buggy patch job FAILED. Sorry.

    If you guys get told the issue 1000 times and put your head in the sand rather then get down to fixing the issue – well as I said Bill Gates will be rolling on the floor with glee.

    June 8th, 2011 at 06:01

  19. chamara

    Mozilla firefox 4 slower than privies version of firefox
    why is it I really suck with this thing when it;s load first time slow
    I think old version better than every thing

    June 16th, 2011 at 20:30

    1. louisremi

      We have numerous resources to help you sort such problems out:

      June 17th, 2011 at 04:21

  20. ozstamps

    louisremi – this is like groundhog day.

    Folks are reporting REAL bugs and issues, and the official response is to direct them to read a vanilla page that has NOTHING whatever to do with the reports.

    Why not post that these *ISSUES ARE BEING LOOKED AT* for a start?

    Why not – as it seems pretty clear no-one cares what users think or report.

    June 17th, 2011 at 04:27

    1. louisremi

      To report REAL bugs please use our REAL reporting/tracking bug tool:

      June 17th, 2011 at 08:07

  21. Patricia

    Can anyone there please take a minute to tell me if I can go back to an older version of Firefox? Would I have to delete this version and lose everything??? Also NOBODY UNDERSTANDS YOUR GD BUGZILLA. Seems to me they should just be able to report the bugs they are getting! I’m so very very very sorry I ever downloaded this miserable “update”!!!!!

    June 17th, 2011 at 08:14

  22. Patricia

    “ouisremi wrote on June 8th, 2011 at 5:53 am:

    You should file a bug in if you think the bug is on our side.
    We carefully test our browsers before releasing them. When there are problems with particular websites, it sometimes has to do with the way those websites are built.”

    What utter nonsense – from what I read out on the internet then everyone’s computer or website is busted but firefox is okay! That even sounds silly! Stop sticking your heads in the sand and undo what you did! This browser is now garbage! Whatever possessed you people to offer this as an update. Why not say truthfully – we wanted to screw with you! …..and now you can just try to figure out our stupid “bugzilla” too!

    June 17th, 2011 at 08:18

  23. Chris

    I appreciate the time you took to make the video. Thank you for that. However, it remains a fairly cryptic, 20-minute, death-by-powerpoint video explaining how to report a bug for newbies.

    While bugzilla may be relatively navigable for mozilla engineers, it is glaringly obvious that the only people who can easily report bugs are – wait for it – mozilla engineers. Sadly, it’s two years since the video was made. Firefox is on an accelerated release path, now at version 19. 19! Yet it is still becoming more and more bug-ridden, maddeningly slower and increasingly less useful as anything other than a testing environment for itself.

    I spent half an hour trying to report a glaringly obvious bug because of the truly byzantine bugzilla search integration. At this point the only thing that makes me leave Firefox as my default browser is No-Script – just in case a family member clicks an evil link without realizing it.

    It is a sad day to recognize that Firefox is no longer my favorite browser. The bug I found is bad enough that if it isn’t fixed in the next release, I’ll probably change the default to Chrome.

    February 19th, 2013 at 09:39

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