Disabling Firefox Resume From Crash

Though to many it’s handy, personally I find Firefox‘s “Resume from Crash” function, well, annoying.  This function makes it so that if Firefox is killed prematurely that the next time you start it you get an (annoying) popup that asks you if you want to restore the previous state/page(s) that Firefox was viewing.

I can understand the advantage, particularly if Firefox is crashing a lot, but for me it’s stable and 99% of the time when it’s been killed prematurely it’s because I wanted/expected it to. Even when it isn’t expected, 99% of those times I don’t really care that I lost what I was viewing. So, for 1/100th of a 1/100th of a chance of being useful, it isn’t worth it. Particularly since any time you reboot with Firefox up, it’s going to pop this up the next time you run it.

Fortunately it’s easy to disable. Simply:

  • Bring up Firefox.
  • Enter “about:config” as a destination URL and go to it.
  • If it warns about the end of the world coming if you touch the configs, say “Ok” and move on.
  • Search for the key “browser.sessionstore.resume_from_crash“. By default this will be set to “true”.
  • Double click on this line. This should switch it from “true” to “false” and should also turn the line to bold.

Done. You probably want to close the browser or browse to another URL to prevent accidentally messing with anymore items in “about:config”.

More on “browser.sessionstore.resume_from_crash“, can be found here:


mozillaZine probably being the definitive source of Mozilla project documentation.


  1. Charles Hand Avatar
    Charles Hand

    Indeed. 99.999% of the time if Firefox crashes itself, it is because of something that came from a web site. So it is not surprising that 99.999% of the time an automatic session resume just crashes Firefox again.

  2. Matt Fahrner Avatar


    An even worse case is if say the reason you killed Firefox is because you hit an infected site. Now when you go to restart Firefox the next time what do you get?

    The infected site.

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