I looking where can I install and try the new browser Firefox Quantum, I didn't find how to get it. Can someone please tell me what repositories or links to download and install it ?

Thank you.

8 Answers 8


Add deb http://ftp.hr.debian.org/debian sid main contrib non-free to /etc/apt/sources.list and install it with this command:

apt install -t sid firefox

This will install only Firefox from unstable. Rest of packages will remain on stretch.

Added by cas 2018-04-19 (because it's quite common for people to want to install something from unstable without upgrading everything to unstable, and the answer here is applicable to more than just firefox):

This is a good answer, but incomplete. There are two more things that need to be done before running apt install -t sid firefox.

  1. Add APT::Default-Release "stable"; to /etc/apt/apt.conf or a file in /etc/apt/apt.conf.d/ so that apt will only install packages from sid/unstable if you explicitly tell it to with -t sid.

    If you don't set the default release to stable, the next upgrade or dist-upgrade will upgrade your entire system to sid. Most people don't want this.

    If you're using a named Debian distribution such as jessie or stretch in your sources.list file, use that name rather than the generic stable.

  2. run apt update to update the local package database.

Finally, apt install -t sid firefox will install not only the firefox package but also the minimum set of upgraded & new packages required to satisfy the new firefox package's dependencies. This will usually just be a few firefox-related packages, built from the same source, but may also include other packages - e.g. if the new firefox depends on a newer version of a library package.

Sometimes it may even cause an important package like libc6 to be upgraded which will then trigger a huge cascade of other package upgrades, effectively upgrading you to a hybrid of stable & unstable. This is generally worse than doing a full dist-upgrade to unstable itself. If this happens, you have two good choices: 1. cancel the firefox upgrade and wait for it to arrive in stable or https://backports.debian.org/; 2. cancel it and upgrade to unstable (which is not as bad as it sounds. In Debian, "unstable" doesn't mean "will crash all the time". It means "pre-release, changes constantly. sometimes things may break and require manual fixing")

  • Complete guide with apt-pinning setup : linuxconfig.org/… Dec 1, 2017 at 16:58
  • Wait -- what if I just want firefox from its usual release channel? Why would I want it from debian's unstable channel? Does debian not offer firefox release? Only ESR and whatever's on this unstable channel?
    – Daniel
    Jan 21, 2018 at 21:00
  • Also, I try that, and I get "The value 'sid' is invalid for APT::Default-Release as such a release is not available in the sources"
    – Daniel
    Jan 21, 2018 at 21:09
  • 4
    If I'm not mistaken, when following this advice, on the next apt-get update && apt-get upgrade apt will try to update all packages to SID (a.k.a. "unstable"), which will leave you with... well, an unstable system.
    – Multisync
    Mar 20, 2018 at 8:42
  • 1
    @multisync add APT::Default-Release "stable"; to /etc/apt/apt.conf or a file in /etc/apt/apt.conf.d so that apt will only install packages from sid/unstable if you explicitly tell it to. (NOTE: if you're using a named debian dist in your sources.list, use that name rather than the generic 'stable').
    – cas
    Mar 22, 2018 at 4:16


If you’re already among the Firefox faithful, you’ll automatically upgrade to Firefox Quantum on November 14. But, if you enjoy the cutting edge, you can try it in Beta on desktop, Android, and iOS. Or, if you’re a web developer, download Developer Edition, which includes brand new, cutting-edge tools for those who build the web.

you simply could wait a few weeks. or you could download the beta which is in tar.gz format

so seems Quantum is not an "all new firefox" but an update.

hey, if it really is only about installing a beta version, then you may simply add the Firefox-beta Repo: https://launchpad.net/~mozillateam/+archive/ubuntu/firefox-next


EDIT: It's now in unstable, so the link changed to https://packages.debian.org/sid/firefox

OLD ANSWER: Firefox Quantum is available in debian experimental (https://packages.debian.org/experimental/firefox). You can probably just download and install the deb file from there.

  • this link is broken
    – gfleck
    Nov 15, 2017 at 10:51

Firefox Quantum (Mozilla 57.0) is available now on the official website, you can download it from here.

wget https://download-installer.cdn.mozilla.net/pub/firefox/releases/57.0/linux-x86_64/en-US/firefox-57.0.tar.bz2
tar xvf firefox-57.0.tar.bz2
sudo unlink /usr/bin/firefox
sudo ln -s ~/firefox-57.0/firefox /usr/bin/firefox

I was just more-or-less forced to do this, because Amazon Prime Video (at least the Indian version), decided it was no longer going to work with the Firefox in stable. That would leave Chrome as the only major installed browser able to run Amazon Video.

Since 57 is available in unstable, the options were to try to backport it, or just try installing it directly and hope it didn't pull in a whole lot of stuff from unstable. Fortunately, as you can see below, it didn't. I think a proper backport would still be better, but it would be a lot more effort.

Specifically,the following packages were installed from unstable:

fontconfig-config libevent-2.1-6 libfontconfig1 libfontconfig1:i386 libfontconfig1-dev libhunspell-1.6-0 libnss3 libnss3-dev

A more conservative approach would be to try to force apt to use only packages from stable, by doing

apt-get install firefox/unstable

but this approach is also slightly more likely (in general) to cause problems, because these are not the version that this firefox package would normally be working with.

Please do note that in general installing packages from unstable is not a good idea.

Having gone with this, nothing bad seems to have happened, as far as I can tell.

root@orwell:/home/faheem# apt-get install -t unstable firefox
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following additional packages will be installed:
  fontconfig-config libevent-2.1-6 libfontconfig1 libfontconfig1:i386 libfontconfig1-dev libhunspell-1.6-0 libnss3 libnss3-dev
Suggested packages:
The following NEW packages will be installed:
  firefox libevent-2.1-6 libhunspell-1.6-0
The following packages will be upgraded:
  fontconfig-config libfontconfig1 libfontconfig1:i386 libfontconfig1-dev libnss3 libnss3-dev
6 upgraded, 3 newly installed, 0 to remove and 3423 not upgraded.
Need to get 44.8 MB of archives.
After this operation, 160 MB of additional disk space will be used.
Do you want to continue? [Y/n] 

Note also that stable let's one install the stable Firefox (version 52) and the new Firefox from unstable (57) side by side.

root@orwell:/home/faheem# dpkg -l | grep firefox
ii  firefox                             57.0.4-1               amd64                  Mozilla Firefox web browser
ii  firefox-esr                         52.5.2esr-1~deb9u1     amd64                  Mozilla Firefox web browser - Extended Support Release (ESR)

And it looks like the Firefox maintainers thought far enough ahead to enable diversions for the firefox executable.

root@orwell:/home/faheem# dpkg -S /usr/bin/firefox
diversion by firefox-esr from: /usr/bin/firefox
diversion by firefox-esr to: /usr/bin/firefox.real
firefox, firefox-esr: /usr/bin/firefox

Although this is an old question, I feel like snap should at least be mentioned. It's a lot more convenient than installing from Sid, in my opinion.

Install snap:

sudo apt install snapd

Install Firefox:

sudo snap install firefox


The script below will download the latest version of Firefox (either from the Stable or Beta channel) and package it into a .deb for installation.

Download and extract the ZIP file linked below and run ./build-firefox.sh from the Terminal.

Specify the --install flag when running the script to automatically install it after building.



I'm not sure why @stanislav-vlasic 's answer was down-voted, I assume because he suggests a specific mirror, so heres a tip on how to get sid for your current debian mirror:

egrep '^deb .*? stretch ' /etc/apt/sources.list \
    | head -n1 \
    | sed 's/stretch/sid/g' \
    | sudo tee --append /etc/apt/sources.list

sudo apt update
sudo apt install -t sid firefox

That appears to have gotten me firefox quantum as of time of writing, no promises on stability!

Ah I understand now, apt pinning is less than trivial, I found a much more concise option posted by: https://linuxconfig.org/how-to-install-firefox-quantum-on-debian-stretch-linux

Which covers in detail, both the deb <your mirror> sid main repository line in /etc/apt/sources.list, as well as how to pin apt.

I'm going to make the following recommendation:

# /etc/apt/preferences.d/sid
Package: *
Pin: release a=unstable
Pin-Priority: -1

Install new firefox:

sudo apt install firefox -t sid

Make the new firefox the default

sudo apt remove firefox-esr
  • can you pease explain more, cause after adding the repo sid it costs me to upgrade from debian stretch to buster, and buster is unstable, can the answer of @stanislav-vlasic solve the issue ??
    – Spartan
    Nov 24, 2017 at 20:17
  • @Spartan my apologies, I missed that consequence in testing. I've amended my recommendation, specifically the inclusion of an "apt pinning" config that prevent unstable/testing updates from being installed. Adding that config should (as far as I know) allow your system to "upgrade" back to the stable Stretch distribution. Dec 15, 2017 at 5:34

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