So at work, my Firefox got automatically updated to 57.0 (Quantum) since I have automatic updates enabled.

Turns out that a lot of add-ons don't work anymore with 57.0, e.g. the session manager and the tab group add-on which I use extensively. It seems that I lost all but the current tab group which I'm not very happy about...

Now, at home I use the same add-ons and I'd like to prevent losing my tab groups so I'm looking for a way to disable automatic updates (which are enabled) before I start Firefox so that I get a chance to save/export my tab groups and find a solution that will work with 57.0 before actually updating to 57.0.

How can I do that?

  • 2
    You should not follow any answer that advises you to disable automatic updates: that's bad advice that can open your computer up to being infected with malware or "hacked."
    – Kaypro II
    Dec 29, 2017 at 6:32

9 Answers 9


The solution to disable automatic updates without running Firefox is as follows (OS is Windows):

  • Edit the file prefs.js, located in %APPDATA%\Mozilla\Firefox\Profiles\xyz.default\ which usually translates to C:\Users\username\AppData\Roaming\Mozilla\Firefox\Profiles\xyz.default\ (Note: username and xyz will vary)
  • Make sure the line user_pref("app.update.enabled", false); is present in the file; if it isn't, add it or modify it. Ignore the warning that this file should not be edited
  • Save and close the file
  • Start and use Firefox without having to worry about automatic updates
  • Optional: Note the button "Check for updates" in the "About Firefox" dialog box. Of course, DO NOT click it until you are prepared and ready to receive the update
  • 2
    Man this browser is looking more and more like google chrome every day, why did they take the automatic updates option out of the GUI. It started with the forced addons signing, now they're limiting what the addons can do and removing the update button from the GUI. What's next, Windows 10 style forced updates? Dec 11, 2017 at 6:19
  • 2
    The above answer is bad advice. By disabling automatic updates, you also disable security patches. In simplistic terms, if you do this it means a website could hack your system and install malware because you never installed the patch to prevent that.
    – Kaypro II
    Dec 29, 2017 at 6:28
  • 2
    The correct advice is to downgrade to Firefox 52 ESR release, which supports XUL extensions will still receive security patches until the summer of 2018 (if I read the graphic correctly). After that, you need to abandon your XUL extensions, but hopefully they'll have been updated by then.
    – Kaypro II
    Dec 29, 2017 at 6:29
  • 4
    The question was specific. The user was currently using Firefox 56, they wanted to prevent the automatic upgrade to Firefox 57, this accomplishes that. The answer does not indicate you shouldn't update Firefox, this answers allows you to choose when that happens, which is great for those who use an extension that cannot be replaced.
    – Ramhound
    Jan 19, 2018 at 2:03

An alternative solution to blocking all updates, is to move to a fork of Firefox which will keep the XUL add-on format, now called "Legacy" by Firefox, while still installing security updates.

Two Firefox forks that keep the legacy add-ons are :

I have tried Pale Moon, and it very nicely imported all my add-ons and profile data. Screen layout was lost and so some small customizations were still required, but in general this is now an exact duplicate of my Firefox version 56, except that it still does security updates.

  • Do the security updates originate from Waterfox, or is there a Mozilla tie-in where Mozilla security updates for Firefox are retrieved and applied? Also, is there an advantage of this over going to Firefox ESR (other than ESR will eventually get the new code base, also)?
    – fixer1234
    Nov 26, 2017 at 20:39
  • 1
    @fixer1234: Both are FF forks, so most (if not all) security updates originate from Mozilla. FF ESR has problems with some addons being unable to save their settings, example LastPass. Also, the ESR version, while based on FF56, is strangely numbered version 52, so some addons refuse to work, requiring at least FF55. In addition, ESR will elapse in several months, while both Waterfox and Pale Moon intend to support XUL add-ons longer, if not forever. It's quite frustrating that the XUL code is still in FF57, only it's just disabled.
    – harrymc
    Nov 26, 2017 at 21:18
  • 1
    @fixer1234: Waterfox is much closer to the current FF than Pale Moon which forked-off several years ago. Pale Moon has its own addons store (fewer), while Waterfox uses Mozilla.
    – harrymc
    Nov 26, 2017 at 21:36
  • Good information in your comments. Consider adding it to the answer. :-)
    – fixer1234
    Nov 26, 2017 at 22:21
  • @harrymc - Are you positive that 52 ESR is based on Firefox 56. The chart seems to indicate 52.5.3 is based on FireFox 52/56 the chart isn't actually clear. Feel free to hint me up in chat though.
    – Ramhound
    Jan 19, 2018 at 2:09

Better off changing user_pref("app.update.mode", 1) to 2


app.update.mode uses an integer value (default 1) to decide the "behaviour" of updating... if you modify this value you are not:

  1. altering the developers code by injecting your own custom code or
  2. stopping upgrades altogether

the following is from https://wiki.mozilla.org/Software_Update:Testing

INTEGER - app.update.mode Default: 1 defines the policy by which background downloads are done, and the amount of user prompting that is required: 0 - download all update types (major/minor) without user intervention, regardless of incompatible extensions installed (they should just be disabled after the update restart) 1 - download all update types (major/minor) only if there are no incompatibilities with enabled extensions, prompt with UI otherwise. 2 - download minor updates only, prompt for major updates, regardless of whether or not all enabled extensions are compatible.

an upgrade to quantum is definitely a major upgrade...


Open your Firefox preferences and use the built-in search bar (present since version 56) to look for "update", then check the option to never update automatically.

That's not recommended though, since you won't get security updates. You can use the latest long-term support release instead: https://www.mozilla.org/firefox/organizations/

  • 1
    Well I don't want to start Firefox, as I have written in my question, because when I do I will most likely get the update immediately.
    – Nassbirne
    Nov 14, 2017 at 20:40
  • It was launched today. If you haven't opened it yet today, it will start downloading it to upgrade it only after you open it a second time, so you can change the setting before that happens. If you are afraid it has already downloaded it, look up "prefs.js disable update" on Google to learn how to find that file and what to change. Nov 14, 2017 at 20:44
  • Yes, I found the prefs.js method before, but the parameter they mentioned is actually missing in my file so I didn't try it.
    – Nassbirne
    Nov 14, 2017 at 20:52
  • 1
    prefs.js only lists the parameters that have been modified from the default values. You can add the option you've found to it. It will be the same as adding it from about:config . Nov 14, 2017 at 21:12
  • @Nassbirne - So how about submitting an answer with specifics on what you did, assuming what you did, prevent an automatic update to Firefox 57 Because using the ESR version of Firefox isn't an option for some people nor is the other answer helpful due to it being a link-only answer.
    – Ramhound
    Nov 14, 2017 at 21:55

In Windows 7 I went to AppData\Local\Mozilla\update. In the update folder, delete whatever is there. Also never check your current version in “Help about Firefox” as this will get you back on the the update treadmill again.

  • On Windows 10 this path is named "AppData\Local\Mozilla\updates" with an s at the end. After reverting to 56, you can go into options to uncheck auto-update, but it will have already started re-downloading quantum, and this auto-download is not aborted even if FF is closed and reopened, so this step is needed to finally abort the Quantum reinstall. Jan 1, 2018 at 10:50

What helped in my case, beside of disabling update in configuration, was just renaming the updater.exe executable in Firefox installation directory.

In case of big errors you can just write simple application that does nothing but restarts Firefox and closes itself, then put it in Firefox directory as updater.exe.

Uninstalling "Mozilla Maintenance Service" and/or also renaming its binary can also help.

  • 1
    I experienced the same Firefox bug. And I did a similar trick: I replaced C:\Users\USER_NAME\AppData\Local\Mozilla\updates directory with an ordinary file so that firefox could not download the updates.
    – Alexey
    Mar 22, 2018 at 8:28

As other users have pointed out, Firefox used to have an about:config option to disable this (called app.update.enabled I think), but the devs no longer trust you so they changed this so auto-updates are hard-coded on. However, if you look at some of the other app.update.* preferences, there is a remaining option the devs overlooked.

They left the app.update.interval option, which specifies the time between auto-updates in seconds. If you set it to some arbitrarily large number, like 432000000, you could make Firefox wait for years, effectively disabling updates. This should be easier and more reliable than having to manually edit some Javascript file which will probably just be reset after the next system package update.

Presumably, the devs will alter or remove this option as well, so the better long term solution is probably to abandon Firefox altogether and use a browser that respects your privacy and doesn't force you to auto-update against your will.

  • Interesting approach. Have you actually tested it to verify that it works?
    – fixer1234
    Jun 25, 2019 at 20:20

I believe a method to prevent upgrade when launching your firefox is to disconnect your computer both from wired and wireless connection before launching and delete upgrade folder, then you can change the config.

Also, according to report, Firefox would check for update when you lick the about firefox page even when automatic update is off so that should be avoided.

See also https://support.mozilla.org/zh-CN/questions/1041197

Edit: For your work computer, I am not sure have the firefox update cleared old addon data yet or simply disabled them, if data for those addon are still there then it will be possible that they could be migrated to the ESR version (extended support)that was based on previous firefox and thus legacy extension would still work. See https://www.ghacks.net/2017/11/14/how-to-move-firefox-legacy-extensions-to-another-browser/ for how to migrate addon data to the ESR version


Problem: Firefox setting to "do not check for updates" still updating.

Turns out my Kaspersky Total Security software was set to check and update apps automatically. Every few days, it would check and update firefox. After turning auto updater to off -- voila! no problems.

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