How to Install Firefox ESR on Ubuntu (26.04, 24.04, 22.04)

Ubuntu’s default Firefox pushes a new major release every four weeks. Each update can shift extension compatibility, privacy defaults, and rendering behavior. Firefox ESR (Extended Support Release) locks the major version for roughly a year while still shipping monthly security patches, so workflows and extensions keep working without surprise breakage.

The Mozilla Team PPA is the most direct way to install Firefox ESR on Ubuntu. It plugs into APT for automatic security updates and runs alongside the Snap build of standard Firefox without conflicts.

Install Firefox ESR on Ubuntu via Mozilla Team PPA

The Mozilla Team PPA is maintained on Launchpad and provides Firefox ESR alongside other Mozilla packages like Thunderbird on Ubuntu. Because it uses APT, security patches arrive automatically with your regular system updates.

Update Ubuntu System Packages

Open a terminal (press Ctrl+Alt+T or search for “Terminal” in the Activities overview) and refresh the package index:

sudo apt update

Commands prefixed with sudo run with administrative privileges. If your account is not in the sudo group, see the sudoers guide for Ubuntu first.

Then upgrade any outdated packages:

sudo apt upgrade

Import Mozilla Team PPA for Firefox ESR on Ubuntu

A PPA (Personal Package Archive) lets developers distribute packages outside the main repositories. The Mozilla Team PPA carries Firefox ESR, a stable Firefox build, and Thunderbird.

Add the PPA:

sudo add-apt-repository ppa:mozillateam/ppa -y

Refresh the package index so the new packages become visible:

sudo apt update

Install Firefox ESR with APT on Ubuntu

Install the firefox-esr package:

sudo apt install firefox-esr

The standard Firefox (Snap) stays installed. Both browsers have separate binaries, menu entries, and profile directories, so they do not interfere with each other.

Verify Firefox ESR Installation on Ubuntu

Confirm the installed version:

firefox-esr --version

Expected output:

Mozilla Firefox 140.8.0esr

The esr suffix confirms the Extended Support Release channel. The minor version (140.8.x) increments with each monthly security patch while the major version (140) stays fixed until the next ESR transition.

Launch Firefox ESR on Ubuntu

Launch Firefox ESR from Terminal

Start Firefox ESR from any terminal:

firefox-esr

Launch Firefox ESR from Ubuntu Applications Menu

Open the Activities overview, select Show Applications, then click the entry labeled Firefox ESR. Pin it to the dock for quick access alongside your standard Firefox icon.

Firefox ESR vs Standard Firefox on Ubuntu

Firefox ESR receives security patches on the same schedule as standard Firefox, but major feature releases arrive only once every 42 weeks instead of every 4 weeks.

Release	Update Frequency	Best For
Firefox ESR	~42 weeks (major), monthly (security)	Stability, enterprise, schools, consistent extension behavior
Standard Firefox	Every 4 weeks	Latest features, developer tools, general browsing

Choose Firefox ESR when critical workflows depend on consistent browser behavior, or when you manage systems for other users who need predictable updates. Standard Firefox is the better pick when you want the newest web technologies and developer tools as soon as Mozilla ships them.

If you still have the default Snap build and want to remove it, the remove the Firefox Snap on Ubuntu walks through the full process. For experimental builds, see how to install Firefox Beta or Nightly on Ubuntu.

Manage Firefox ESR on Ubuntu

Set Firefox ESR as Default Browser on Ubuntu

Firefox ESR installs alongside the default Firefox build, so both browsers remain available. Launch the standard browser with the firefox command or its dock icon, and open the ESR build with firefox-esr or the “Firefox ESR” entry in the Activities overview.

To make Firefox ESR the default for web links, open Settings > Default Applications and change the Web dropdown to Firefox ESR. Alternatively, set the default from the terminal:

xdg-settings set default-web-browser firefox-esr.desktop

Revert to the standard build at any time with xdg-settings set default-web-browser firefox.desktop.

Update Firefox ESR on Ubuntu

Firefox ESR updates arrive through APT alongside your regular system updates. To update only Firefox ESR without upgrading every package:

sudo apt update && sudo apt install --only-upgrade firefox-esr

If no newer version is available, APT reports that firefox-esr is already at the latest version.

Remove Firefox ESR from Ubuntu

Uninstall the Firefox ESR package and clean up orphaned dependencies:

sudo apt remove firefox-esr

sudo apt autoremove

If you no longer need other packages from the Mozilla Team PPA (such as Thunderbird), remove the repository and refresh APT:

sudo add-apt-repository --remove ppa:mozillateam/ppa -y

sudo apt update

Confirm removal by checking the package status:

apt-cache policy firefox-esr

After both the package and PPA are removed, the expected output is:

N: Unable to locate package firefox-esr

Removing the package does not delete your bookmarks, passwords, history, or extensions. Firefox ESR stores user data in ~/.mozilla/firefox-esr/ and cached files in ~/.cache/mozilla/firefox-esr/. Delete those directories only if you are sure you no longer need the data.

Frequently Asked Questions

Conclusion

Firefox ESR is running on Ubuntu with automatic security patches from the Mozilla Team PPA. The major version stays stable for predictable extension and workflow compatibility. For related browser management, see how to remove the Firefox Snap on Ubuntu or install Firefox Beta or Nightly on Ubuntu.