My first Firefox extension! (FlashTracer)

Ok, it does nothing particular new, but it’s my first one 🙂

What it does?
If you have a flash debug player version you will see in the firefox sidebar all the swf trace output while running any of the swf in a browser window.
I have to say thanks to jayjam (Giuseppe Montemurro) who talks about the mm.cfg file yesterday at the From A to Web Adobe conference. I’d never read about this cool feature of the debug players.. and so I decided to make it as firefox extension.
I took 1 hour to make the XUL and js files, while the .xpi package was driving me crazy!.. the documentation is really terrible for my point of view.

Download and install FlashTracer from the Firefox extension page.

UPDATE: A new flash tracer called fbtracer has been released. This new extension is integrated into Firebug. Read more here

P.S. If you’re running the new 9,0,28 Flash plugin probably you noticed this extension wont work anymore. Adobe changed something and the plugin doesn’t read as previously the mm.cfg file so I’m invetigating on it. In the meanwhile you should tell the extension to point to this file: C:\Documents and Settings\{user}\Application Data\Macromedia\Flash Player\Logs\flashlog.txt.

For mac osx it should be: username:Library:Preferences:Macromedia:Flash Player:Logs:flashlog.txt

Using this path the flash tracer works again.

For discussing about this extension please use the forum instead of the comments here 🙂

  • “max lines” is sweeeeet! thank you!

  • Great! UTF problem solved in update! Non-latin characters got the life )) Thanx for this update.
    Once again – this extension is a Gem ))

  • Jeff

    Can you put up old versions of the extension? V2.3.1 does not work in FF2. v2.1.5 was the last one that did.

  • The updated FlashTracer xpi install fails on because of an invalid hash. Could you re-upload please?
    Thanks – Nils.

  • try just to install the .xpi file directly from instead of using the FF update feature

  • Ok, so I normally don’t post comments, but I really need to use this plugin and am stuck on the install. From what I read it is going to be fantastic once I get installed… So here is info you might need.
    1.) Using Vista + Firfox + FlashTracer 2.3.1
    2.) Installed Flash Debug Version
    3.) Create mm.cfg in my user folder (C:/Users/Travis/mm.cfg).
    4.) Placed the following contents in that file…
    5.) Created the flashlog.txt in my user directory… (C:/Users/Travis/flashlog.txt) blank file.
    6.) Opened up browser, see the flashtracer, but it keeps telling me it can’t find the flashlog.txt file. Here is the exact error….
    using: C:\Users\Travis\mm.cfg
    flashlog.txt file does’t exists. Open settings dialog first.
    So… what exactly does “Open settings dialog first” mean? I right click on the SWF and select “Settings” but not sure if that is what you mean.
    I can’t seem to figure this out. Please reply as soon as you can.

  • For Travis:
    you can find the “settings” dialog by clicking the “preferences” button placed in the bottom right corner of the FlashTracer Window.

  • [quote]try just to install the .xpi file directly[\quote]
    that did the trick – thanks.
    Travis – I don’t think you can choose the path, it’s predetermined by flashplayer. Try:
    C:\Users\USERNAME\AppData\Roaming\Macromedia\Flash Player\Logs\flashlog.txt

  • Anonymous

    Thank You!

  • Mark Huggins

    Do you plan to update flash tracer to be compatible with FF3

  • Alessandro

    It’s already FF3 compatible

  • Ramanuja

    If I open Flash tracer, I get the following message- “using: C:C:\Documents and Settings\Administrator\mm.cfg”.
    I have done all the configurations required regarding mm.cfg and flashlog.txt.
    I have the flash debug player. When I run my module with a trace statement, it appears in the flashlog.txt.
    I am unable to configure flash tracer. Please help me!!

  • Ramanuja

    Forgot to mention this: In the settings tab, I can browse and select the flashlog.txt file. It is placed in the default. I have not changed it from “C:\Documents and Settings\Administrator\Application Data\Macromedia\Flash Player\Logs”. If I click on OK and come back to the settings tab, the Select output file textbox is still empty! It is not retaining any values that I enter.

  • Dave

    I’m getting increasingly frustrated that I can’t get this plugin to work.
    I have several trace() calls in a simple MXML app I’ve written – I’ve surrounded these with graphic function calls, so I know the trace() calls are being made. However, nothing shows up in FlashTracer.
    I’m using the latest version of Firefox and the latest debug flash player. I have also ensured that flashlog.txt is in the correct location (…{user}\Application Data\…) as specified, as well as making sure that flex-config.xml isn’t causing the trace() calls to be stripped from the compiled SWF (
    Very frustrating indeed.. I don’t know what to do to get this working =(

  • I have the same problem as Dave. I’ve tried installing the debug version for a few days now. I had to create a folder in my App Data/Macromedia folder and I see that the log text file is being created however, nothing is being written to it.
    Maybe, it needs to be in Adobe folder. Very frustrating fo sho

  • seb

    mac osx 10.5.4.
    installed latest debug flash player 9.0.124, firefox
    info panel says:
    “using /Users/myname/mm.cfg
    however this file does not exsist.
    No idea what I would need to put in this file…? will it work if I make this file or is there an issue with the latest security in FFox that cant be bypassed? Tried reading through all the above comments but it wasn’t clear; made my own cfg file, but that didn’t seem to fix the issue. the display stays fixed on the words ‘using: …cfg’ and does not show any trace feedback – thanks, seb.

  • dan

    Tracer stops working when you have an AIR app running. You get error#2044
    As soon as you exit the AIR app tracer starts working again.

  • Hi again. And once again thanks for a fantastic plugin. I do have another question about something different in the FF3 version than the FF2 version: I’m using filters, and previously I had one rule for “–” and a different one for “—” and that worked in FF2. In FF3 everything is caught by the “–” filter no matter which order the filters are defined in the list. Is this something that can return to the way it was?

  • Tim

    Thanks for clearing that up dan. I was worried when Flash Tracer stopped working this morning (Due to running an AIR app in the background) 😀

  • Terry Corbet

    I am a bit baffled by the comments which say that Flash Tracer does not work with AIR. I am sure that the posters are [were] experiencing real problems, but I’d like to state that I continue to get marvelous results from using this combination:
    Windows XP
    Firefox 3.x
    Flex SDK 3.1
    Since I am concurrently working on both Flex and AIR deliverables, I just leave the Flash Tracer window open all day long and watch trace statement output no matter whether I am testing a Flex or an AIR app.
    So, the reason for my posting is to ask if you could consider making a small change. The output from a trace statement in Flex adds no extraneouse NL, but in AIR it does. Since the real estate of a desktop gets very cluttered with all the windows we have open, the additional CR\LF annoyance is one that I would be so happy to see go away!
    Thanks, as always, for your indispensible plug-ins.

  • FlashTracer 2 for Firefox 2.0.*

    I dont know what happened to the link of my FlashTracer extensions on Mozilla extensions page.. it simply has been removed.
    It’s a while I don’t…

  • Kun Janos

    Hi all
    I experienced bugs with flash tracer: when there are too many trace lines in the output, the tracer freezes and causes mozilla to hang up 🙁 Works well when just a few lines, but if the log file is bigger then 10-15 KB then it just freezes 🙁

  • Hey Alessandro, kudos on flash tracer I have used if for about a year now, but I wanted to inquire if it will support policy logs as well?
    With the latest security updates to the players since April 08 I’ve had a few apps silently fail due to the new policy files. But since they fail quietly it’s hard to trouble shoot.

  • SAk

    :(, :(, i try each and every thing regarding flash trace setting but :(, tell me one thing where should i create mm.cfg file plz plz plz help me out
    waiting for reply

  • Elango

    Tracer stops working when you have an AIR app running.
    Is there any way we can use Tracer when running AIR application in the background?

  • Anonymous

    You say….
    “If you have a flash debug player version you will see in the firefox sidebar all the swf trace output while running any of the swf in a browser window.”
    but thats not true.
    Because some online flashgames like could block some traces.
    With this method:
    enemy:undefined typ:undefined

  • B

    Thanks Elango I was wondering why mine wasnt working and it was because of the adobe air media player thing

  • Ken Hammond

    Help, I can’t get Flash Tracer to work with Firefox 3. When upgrading from Firefox 2 it tells me that the add-in isn’t compatible and disables it. I use Flash Tracer all the time and would like to be able to use it Firefox 3.

  • Hi, thanks for the tracer, but since I installed the extension the back and forward buttons are gone. Any workaround to have them back?
    thanks in advanced

  • Would be SO great if you made this work for the new Firefox version 🙂

  • Danny

    Thanks, and why don’t you update the Mozilla with v2.3.1? Currently it shows v2.2.0, which is incompatible with Firefox 3.

  • Greg

    Has anyone noticed that this does not work with Flash Player 10?
    The instructions for fixing the tracer are obscure. What does “tell the extension to point to this file…” mean? How do I “tell the extension” to point to the file? When I go to tools>addons>flashTracer the options button is grayed out. Sephiroth can you please clarify these instructions? Thanks.

  • seb

    Does somebody still has an older executeable of firefox where Flashtracer works on or helps me downgrade my current version (3.0.7) that don’t allow FlashTracer!
    All ideas are appreciated,

  • Alessandro

    Actually FlashTracer 2.3.1 works on Firefox 3.0.7 for me.

  • I have a problem with cyrillic symbols. Can you fix it?

  • Hi Alessandro,
    I have FF 3.0.10 & tried installing Flash Tracer from It doesnt seem to work at. I have Flash Player 10 on my system. I have create flashlog.txt in both C:\Documents and Settings\rajeshk\Application Data\Adobe\Flash Player\Logs & C:\Documents and Settings\rajeshk\Application Data\Macromedia\Flash Player\Logs but still doesnt work. Btw I created these folders & put a blank file as they were not there.

  • Yeah it really works with lastest Firefox. I just updated to FF 3.0.10 from FF 2 and still using ‘FlashTracer’.
    The only thing u need the flashtracer from this site(v2.3.1). The plugin located in the FF plugin site is older one (v2.2.0) and is not supported to latest FF.

  • Diego

    Hi, it seems that it doesn’t works with FF 3.5, can you check it?
    Thanks for the great extension!

  • Michal

    Hi, great extension, thanks.
    At some point it seemed that it stopped working – I suspected Firefox 3.5 or a new version of Flash player to be broken. It took me quite a long time to figure out that Flash player do not log messages to the text file while ANY AIR application is running.
    Hope this saves someone’s time 🙂

  • Chris

    Any plans upgrading it for FF 3.5.2? I REALLY miss this neat little plug-in. :.(

  • FlashTracer for Firebug

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