Mozilla Firefox is the default browser on many Debian desktop installs, but the packaging story changed: current stable releases ship firefox-esr (Extended Support Release) from Debian main, while the rolling firefox package lives on Mozilla’s APT repository—not in deb.debian.org alone.
This guide covers install Firefox on Debian for Debian 11 (Bullseye), 12 (Bookworm), and 13 (Trixie): firefox-esr from Debian, Mozilla APT for the latest release, Snap, Flatpak, and a .tar.xz from firefox.com, plus updates and uninstall. I ran these paths on Debian 13 and kept real terminal output below. For Google’s browser, see install Google Chrome on Debian.
Tested on: Debian 13 (trixie); kernel 6.12.94+deb13-amd64; amd64; firefox-esr 140.12.0esr (Debian); firefox 152.0.3 (Mozilla APT).
firefox-esr, Mozilla firefox, Snap, or Flatpak). You can install firefox-esr and Mozilla firefox together—they are separate packages—but only one should own /usr/bin/firefox for a predictable firefox command.
Choose an install method
| Method | Best for | Version on test host |
|---|---|---|
apt install firefox-esr |
Default Debian path; security team updates | 140.12.0esr |
Mozilla APT (firefox) |
Latest release via apt |
152.0.3 |
| Snap (snapcraft.io/firefox) | Sandboxed install when snapd is already in use |
152.0.3-1 stable |
Flatpak (org.mozilla.firefox) |
Flathub sandbox without Snap | 152.0.3 |
.tar.xz from Mozilla |
No repo; unpack under /opt or $HOME |
152.0.3 (~85 MB) |
On Trixie, apt install firefox without the Mozilla repo fails—use firefox-esr or add Mozilla’s repository first.
Check what is already installed
. /etc/os-release && echo "$PRETTY_NAME"
firefox --version 2>/dev/null || echo "firefox: not installed"
which firefox 2>/dev/null
dpkg -l firefox firefox-esr 2>/dev/null | grep ^ii
apt-cache policy firefox firefox-esr | head -16Before adding Mozilla’s repo on a clean trixie desktop:
Debian GNU/Linux 13 (trixie)
Mozilla Firefox 140.12.0esr
/usr/bin/firefox
ii firefox-esr 140.12.0esr-1~deb13u1 amd64 Mozilla Firefox web browser - ESR
firefox:
Candidate: (none)
firefox-esr:
Installed: 140.12.0esr-1~deb13u1
Candidate: 140.12.0esr-1~deb13u1The firefox command on Debian often points at ESR even though the package name is firefox-esr (Debian Wiki — Firefox).
Install Firefox ESR from Debian (recommended default)
firefox-esr is maintained in Debian main with security support—no third-party repository:
sudo apt update
sudo apt install -y firefox-esr
firefox --versionMozilla Firefox 140.12.0esrOptional language packs: apt-cache search firefox-esr-l10n | head -5 (for example firefox-esr-l10n-de).
Desktop entry:
ls /usr/share/applications/firefox-esr.desktop/usr/share/applications/firefox-esr.desktopThis path matches what most Debian Firefox documentation describes for stable suites.
Install the latest Firefox from Mozilla APT
Mozilla publishes .deb packages and an official APT source (install Firefox on Linux, Nightly deb announcement). Works on Bullseye, Bookworm, and Trixie when sudo is available.
Add the signing key and repository
sudo apt install -y wget gpg
sudo install -d -m 0755 /etc/apt/keyrings
wget -q https://packages.mozilla.org/apt/repo-signing-key.gpg -O- \
| sudo tee /etc/apt/keyrings/packages.mozilla.org.gpg > /dev/null
echo "deb [signed-by=/etc/apt/keyrings/packages.mozilla.org.gpg] https://packages.mozilla.org/apt mozilla main" \
| sudo tee /etc/apt/sources.list.d/mozilla.list
sudo apt update
apt-cache policy firefox | head -10deb [signed-by=/etc/apt/keyrings/packages.mozilla.org.gpg] https://packages.mozilla.org/apt mozilla main
firefox:
Candidate: 152.0.3~build1
152.0.3~build1 500
500 https://packages.mozilla.org/apt mozilla/main amd64 PackagesInstall the release package
sudo apt install -y firefox
firefox --version
dpkg -l firefox firefox-esr | grep ^iiMozilla Firefox 152.0.3
ii firefox 152.0.3~build1 amd64 Mozilla Firefox
ii firefox-esr 140.12.0esr-1~deb13u1 amd64 Mozilla Firefox web browser - ESRBoth packages can coexist. firefox-esr remains available as its own binary:
firefox-esr --versionMozilla Firefox 140.12.0esrInstall Firefox with Snap
Snap ships a Mozilla-published build (Firefox on Snapcraft):
sudo apt install -y snapd
sudo snap install firefox
snap info firefox | head -14name: firefox
summary: Mozilla Firefox web browser
publisher: Mozilla**
latest/stable: 152.0.3-1 2026-06-25 (8568) 265MB -
esr/stable: 140.12.0esr-1 2026-06-16 (8472) 258MB -Launch with firefox from the Snap menu entry, or snap run firefox. Use the esr/stable channel when you want ESR inside Snap: sudo snap install firefox --channel=esr/stable.
Install Firefox with Flatpak
When Flathub is configured:
flatpak search firefox | head -3
sudo flatpak install -y flathub org.mozilla.firefox
flatpak run org.mozilla.firefox --version 2>/dev/null || trueFirefox Fast, Private & Safe Web Browser org.mozilla.firefox 152.0.3 stable flathubFlatpak updates independently of apt: flatpak update org.mozilla.firefox.
Install Firefox from a release archive
Download the current Linux x86_64 build without adding a repository (firefox.com Linux download):
curl -sI 'https://download.mozilla.org/?product=firefox-latest&os=linux64&lang=en-US' | grep -iE '^(location|content-length)'location: https://download-installer.cdn.mozilla.net/pub/firefox/releases/152.0.3/linux-x86_64/en-US/firefox-152.0.3.tar.xz
content-length: 84825836Extract and run:
cd /tmp
wget -q --show-progress 'https://download-installer.cdn.mozilla.net/pub/firefox/releases/152.0.3/linux-x86_64/en-US/firefox-152.0.3.tar.xz'
tar -xf firefox-152.0.3.tar.xz
./firefox/firefox --versionMozilla Firefox 152.0.3Move to a permanent path if desired:
sudo mv firefox /opt/firefox
sudo ln -sf /opt/firefox/firefox /usr/local/bin/firefox-portableUse firefox-portable (or the full path) so you do not overwrite /usr/bin/firefox from firefox-esr or Mozilla firefox.
Set the default browser
After installing a .deb build:
xdg-settings get default-web-browser
xdg-settings set default-web-browser firefox.desktop
# or for ESR only:
# xdg-settings set default-web-browser firefox-esr.desktopGNOME and KDE expose the same choice under Settings → Default applications.
Update Firefox
| Channel | Command |
|---|---|
| firefox-esr (Debian) | sudo apt update && sudo apt install --only-upgrade firefox-esr |
| firefox (Mozilla APT) | sudo apt update && sudo apt install --only-upgrade firefox |
| Snap | sudo snap refresh firefox |
| Flatpak | flatpak update org.mozilla.firefox |
| Tarball | Download a newer .tar.xz and replace the directory |
Confirm with firefox --version. List packages with list installed packages on Debian.
Uninstall Firefox
Mozilla APT firefox package
sudo apt remove firefoxDry-run on the test host:
REMOVING:
firefox
Remv firefox [152.0.3~build1]firefox-esr stays installed if you added it from Debian.
Debian firefox-esr
sudo apt remove --purge firefox-esrMozilla repository
sudo rm -f /etc/apt/sources.list.d/mozilla.list /etc/apt/keyrings/packages.mozilla.org.gpg
sudo apt updateSnap / Flatpak / tarball
sudo snap remove firefox
flatpak uninstall org.mozilla.firefox
sudo rm -rf /opt/firefox /usr/local/bin/firefox-portableTroubleshooting
| Symptom | Likely cause | Fix |
|---|---|---|
Package 'firefox' has no installation candidate |
Debian ships ESR only | sudo apt install firefox-esr or add Mozilla APT |
firefox still shows ESR after Mozilla install |
firefox-esr owns /usr/bin/firefox |
Check dpkg -S /usr/bin/firefox; reinstall firefox or call /usr/lib/firefox/firefox |
| Snap Firefox won’t open on SSH server | No GUI / Wayland session | Use firefox-esr or Mozilla .deb on desktop; Snap needs a user session |
| Flatpak “No remote found” | Flathub not added | flatpak remote-add --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo |
| Two Firefox icons | Both ESR and Mozilla installed | Normal; pick one default in xdg-settings |
| Old Mozilla repo / 404 in browser | Artifactory URLs are for apt, not browsing | Use packages.mozilla.org/apt via sources.list only |
References
- Mozilla Support — Install Firefox on Linux
- Firefox Linux download
- Debian Wiki — Firefox
- Firefox on Snapcraft (Debian)
- Mozilla Nightly deb packages for Debian-based distros
- On-site: install Google Chrome on Debian, install sudo on Debian, apt command, wget, curl, list installed packages
Summary
Install Firefox on Debian with sudo apt install firefox-esr when you want the supported Debian main browser. For the current release, add Mozilla’s APT repository and run sudo apt install firefox. Snap, Flatpak, and the .tar.xz from firefox.com work when you prefer sandboxed or portable installs. On Trixie, plain apt install firefox from Debian alone fails—use ESR or Mozilla’s repo—and verify with firefox --version.
