A Mattermost install on Linux starts with choosing a package format that matches your distro and your update habits. The desktop app is an Electron client (a web app wrapped in a native window) that talks to a Mattermost server.
This guide covers apt, Snap, rpm, Flatpak, AppImage, tarball and pacman installs for Mattermost Desktop 6.3.1. Each method comes with the exact commands, a version check, update steps and a clean removal route.
What the Mattermost desktop app adds
Mattermost is an open source team chat platform with a self-hostable server. The desktop client adds native features on top of the web app. Yuya Ochiai started it as electron-mattermost before it became the official client.
- A server dropdown for switching between several Mattermost servers
- Dedicated tabs for Channels, Boards and Playbooks
- Desktop notifications with badges for unread channels and mentions
- Protocol links that open Mattermost links directly in the app
- Background running that keeps the number of open windows down
Plugins add integrations such as GitHub, Microsoft Teams and Zoom. Audio calls and screen sharing also work in the desktop client. Which ones you get depends on the server plan and the plugins your admin enables.
Requirements before the Mattermost install
The desktop app is only a client, so you need a Mattermost server URL before the first launch. Your admin sends it in the invitation email. Mattermost’s download page lists Ubuntu 22.04 or later as the supported Linux baseline.
- A server URL such as https://mattermost.example.com
- A 64-bit x86_64 or aarch64 machine
- sudo rights for apt, Snap, rpm and pacman installs
- A local drive for the install because Mattermost does not support network shares
uname -m
The command prints x86_64 for Intel and AMD or aarch64 for 64-bit ARM. Release file names mix x64, x86_64, arm64 and aarch64 depending on the format, so match your architecture before you download anything.
Choose a Mattermost install method
Mattermost’s release notes list only the tarball as official and label the deb, rpm, AppImage and Flatpak files unofficial. The install docs still call the apt repository official. Update handling is the main difference between the methods.
- apt repository: Ubuntu, Debian and Linux Mint with updates through apt
- Snap: any distro with snapd, maintained by the Snapcrafters community
- rpm: Fedora, RHEL, Rocky Linux and AlmaLinux with manual updates
- Flatpak: any distro, sandboxed, from Flathub or a GitHub file
- AppImage: one executable file that needs no root
- Tarball: the portable official build that needs no root
- pacman: Arch Linux and derivatives from the Extra repository
I would pick the apt repository on Ubuntu and the Extra package on Arch because both update with the system. Everything else works but needs a manual step or comes from a community maintainer.
Mattermost install on Ubuntu and Debian with apt
The apt repository gives you updates through the normal apt commands, which suits Ubuntu 22.04 or later and Ubuntu-based distros such as Linux Mint and Pop!_OS. The install docs name Debian 9 and Ubuntu 20.04 as the oldest releases for it.
Add the Mattermost apt repository
curl -fsS -o- https://deb.packages.mattermost.com/setup-repo.sh | sudo bash
This downloads Mattermost’s repository setup script and runs it as root. The curl flags are -f to fail on HTTP errors, -s to silence progress output, -S to still print errors and -o- to write the script to standard output.
I would read the script before running it as root. Save it with curl -fsS -o setup-repo.sh followed by the URL, open it with less and then run sudo bash setup-repo.sh.
Install the package and check its origin
sudo apt install mattermost-desktop
apt policy mattermost-desktop
The first command installs the app and its dependencies from the new repository. The second prints the installed version and the repository it came from, which confirms that later updates arrive through apt. The Grafana guide shows the same signed APT repository pattern on Ubuntu.
Fix apt signature errors after the GPG change
curl -fsS -o- https://deb.packages.mattermost.com/setup-repo.sh | sudo UPDATE_GPG_KEY=yes bash
Mattermost changed the GPG signing certificate (the signature check apt applies to packages) for this repository. If apt update reports a signature error on a machine you set up earlier, rerun the setup script with UPDATE_GPG_KEY=yes so it overwrites the old certificate.
Installations that skipped the setup script need manual work. Fetch the new public key from deb.packages.mattermost.com and replace the old one in your apt keyring. Mattermost’s docs flag this case explicitly.
Install a standalone deb file
sudo apt install ./mattermost-desktop_6.3.1-1_amd64.deb
Systems that cannot reach the repository can use the deb file from the GitHub releases page. The ./ prefix makes apt treat the argument as a local file so it still resolves dependencies. This route gives no automatic updates and the ARM file name ends in _arm64.deb.
Install Mattermost Desktop with Snap
Snap works on any distro that runs snapd (the background service that manages snaps). Ubuntu includes it by default. On other Debian-based systems the guide to install Snap on Linux covers the setup.
sudo apt install snapd
sudo snap install mattermost-desktop
snap list mattermost-desktop
Skip the first line when snapd already exists. The second line installs the snap and the third prints its version and channel. Snaps refresh themselves in the background. Run sudo snap refresh mattermost-desktop to force a check.
The Snapcrafters community maintains this snap and the Snap Store page says upstream does not necessarily endorse it. At the time of writing its latest build dates from 15 October 2026. The guide to install Chromium on Ubuntu shows the same Store flow for another app.
Mattermost install on Fedora and RHEL with rpm
Fedora and RHEL family systems such as Rocky Linux and AlmaLinux use the rpm file from Mattermost’s GitHub releases page. The release notes mark these rpm builds as beta and unofficial, so plan on manual updates.
Download and verify the rpm
curl -fLO https://releases.mattermost.com/desktop/6.3.1/mattermost-desktop-6.3.1-linux-x86_64.rpm
sha256sum mattermost-desktop-6.3.1-linux-x86_64.rpm
The curl flags are -f to fail on HTTP errors, -L to follow redirects and -O to keep the remote file name. Swap x86_64 for aarch64 on 64-bit ARM machines.
Compare the printed SHA-256 checksum (a fingerprint that exposes altered files) with the value listed under the same release on GitHub. A mismatch means a damaged or tampered download, so do not install it.
Install with dnf or rpm
sudo dnf install ./mattermost-desktop-6.3.1-linux-x86_64.rpm
rpm -q mattermost-desktop
Use dnf for a local rpm because it resolves dependencies from your enabled repositories. The plain rpm -i command skips that step and fails when a library is missing. The rpm -q line prints the installed version.
Fedora’s own repositories carry no Mattermost Desktop package at the time of writing. A Fedora Discussion thread on that gap points to the way Electron apps bundle their own runtime.
Upgrade an rpm install
sudo rpm -U mattermost-desktop-6.3.1-linux-x86_64.rpm
Download the newer rpm and run it through rpm -U, which upgrades an installed package or installs it when missing. Use the uppercase flag because lowercase -u is not the upgrade option. Running dnf install on the newer file gives the same result.
Mattermost install on Arch Linux with pacman
Arch carries mattermost-desktop in the Extra repository, so pacman handles it like any other package. The pacman guide on this site covers the command in more detail. The package depends on a system Electron build (electron41 for version 6.2.2) instead of bundling one.
Install from the Extra repository
sudo pacman -S mattermost-desktop
pacman -Qi mattermost-desktop
The first command installs the package and the second prints its version and dependencies. At the time of writing the package page listed 6.2.2 and flagged it out of date while 6.3.0 sat in Extra-Testing. Check the version before you rely on it.
Use the AUR when Extra lags
yay -S mattermost-desktop-bin
The AUR (Arch User Repository) lists mattermost-desktop-bin, a precompiled build that sat at 6.3.0 at the time of writing. AUR helpers such as yay fetch it for you. Read the PKGBUILD first because AUR packages are community uploads.
Neither the Extra package nor the AUR build had 6.3.1 at the time of writing, which makes the tarball the quickest way to reach that release and its security fixes on Arch.
Install Mattermost Desktop with Flatpak
Flatpak runs the app in a sandbox on any distro and ships builds for x86_64 and aarch64. Mattermost’s docs describe a Flatpak built on the Freedesktop 25.08 runtime with an Electron base app and Wayland support enabled by default.
Install from Flathub
flatpak install flathub com.mattermost.Desktop
flatpak run com.mattermost.Desktop
Flathub lists Mattermost under the app ID com.mattermost.Desktop (version 6.3.1 at the time of writing) as an unverified community package that Mattermost, Inc. does not support. The RetroArch guide shows how to set up Flathub first.
Install the Flatpak file from GitHub
flatpak install ./mattermost-desktop-6.3.1-linux-x86_64.flatpak
Mattermost’s docs use this local-file route. Download the matching x86_64 or aarch64 file from the GitHub releases page and install it. The release notes tag these builds as beta and the app still pulls its runtime dependencies from Flathub.
Review the sandbox permissions
flatpak info --show-permissions com.mattermost.Desktop
The command prints the filesystem, device and socket access the sandbox grants. Mattermost’s docs warn that the sandbox can affect some integrations and file access patterns. Use flatpak override to widen access when a file dialog cannot see a folder.
Run Mattermost from the tarball or AppImage
Both formats need no root access and no package manager. The tarball is the only Linux build the release notes call official. The AppImage (a single executable file that bundles its dependencies) is listed as unofficial.
Use the tarball
VER=6.3.1
curl -fLO "https://releases.mattermost.com/desktop/${VER}/mattermost-desktop-${VER}-linux-x64.tar.gz"
sha256sum "mattermost-desktop-${VER}-linux-x64.tar.gz"
mkdir -p ~/apps/mattermost-desktop
tar -xzf "mattermost-desktop-${VER}-linux-x64.tar.gz" -C ~/apps/mattermost-desktop
Set VER to the current release and use linux-arm64 on ARM machines. The tar flags are -x to extract, -z to decompress gzip and -f to name the archive. The -C flag sets the target directory.
Compare the sha256sum output with the checksum on the GitHub release page before extracting. After extraction run the mattermost-desktop binary inside the extracted directory. Help then Version inside the app confirms the release you are on.
Use the AppImage
VER=6.3.1
curl -fLO "https://releases.mattermost.com/desktop/${VER}/mattermost-desktop-${VER}-linux-x86_64.AppImage"
chmod +x "mattermost-desktop-${VER}-linux-x86_64.AppImage"
"./mattermost-desktop-${VER}-linux-x86_64.AppImage"
The chmod +x line marks the file executable and the last line runs it. The ARM file is named linux-arm64.AppImage while the Intel and AMD one uses x86_64. Most AppImages also need FUSE 2 on the host.
Ubuntu packages FUSE 2 as libfuse2 on 22.04 and as libfuse2t64 on 24.04 and later. Install whichever name apt offers with sudo apt install libfuse2t64 or the plain libfuse2 variant.
Fix the sandbox error on Ubuntu 24.04
sysctl kernel.apparmor_restrict_unprivileged_userns
Ubuntu 24.04 restricts unprivileged user namespaces through AppArmor (a Linux security module). A printed value of 1 means the restriction is active. Electron AppImages often abort with a SUID sandbox error under that setting.
Prefer the apt package or Flatpak on those releases. The –no-sandbox flag gets the AppImage running but turns off Chromium’s sandbox, so use it only for a short test.
Connect the app to your Mattermost server
- Launch Mattermost from the application menu or a terminal.
- Enter the server URL and a display name when prompted.
- Sign in with your credentials.
- Pick or join a team.
Package installs add a launcher entry to your desktop environment’s application menu. Run whereis mattermost-desktop to locate the binary when the entry is missing. A display name helps when you connect one client to several servers.
Single sign-on logins through providers such as Google or Entra ID briefly leave the app while the provider authenticates you and return afterwards. To confirm the release, open the More menu in the top left corner and pick Help then Version.
Host a Mattermost server for the desktop app
Unlike Slack, where anyone can create a workspace from a signup page, the Mattermost desktop app needs an existing server. Mattermost’s docs say the server runs on any 64-bit Linux system. A single host suits development and testing while production splits out the database.
- 1 vCPU and 2 GB RAM supports about 1,000 users
- PostgreSQL 15 or later
- Inbound ports 80 and 443 for HTTPS plus 8065 for the System Console
- An NGINX reverse proxy (a front-end server that forwards requests) with TLS
The docs cover Ubuntu and Debian packages, a RHEL tarball setup, a manual tarball install and an Azure Native VM option. If you would rather run Matrix, the guide to install Element on Linux covers that client.
Update Mattermost Desktop on Linux
Version 6.1.0 introduced in-app update notices. On Linux the notice opens the GitHub releases page and you install the new package by hand. Version 6.3.1 carries medium severity security fixes, so check which release you run.
# apt
sudo apt update && sudo apt upgrade mattermost-desktop
# Snap
sudo snap refresh mattermost-desktop
# Flatpak
flatpak update com.mattermost.Desktop
# pacman
sudo pacman -Syu
Help then Check for Updates or Settings then Updates then Check Now starts a manual check inside the app. The rpm AppImage and tarball methods have no update channel so repeat their download steps. A cron job from the guide to automatic updates with cron can run the package manager lines on a schedule.
Uninstall Mattermost Desktop and remove its data
# apt
sudo apt remove mattermost-desktop
# Snap
sudo snap remove --purge mattermost-desktop
# rpm
sudo dnf remove mattermost-desktop
# Flatpak
flatpak uninstall --delete-data com.mattermost.Desktop
# pacman
sudo pacman -Rns mattermost-desktop
# tarball or AppImage: delete the file or the extracted folder
# optional: reset configuration and session data
rm -rf ~/.config/Mattermost
Each line removes the application for one install method. On Linux the configuration lives in ~/.config/Mattermost. Deleting that folder resets the desktop configuration and session data, so you sign in again afterwards.
Flatpak keeps app data under ~/.var/app, which the –delete-data flag clears. The apt removal leaves the Mattermost repository configured, which helps when you reinstall later.
Troubleshoot a Mattermost install on Linux
The tray icon crashes or misbehaves
The desktop changelog lists crashes on some Linux desktops caused by an upstream notification library bug. The workaround is turning off the Mattermost tray icon in Desktop Settings. A left click on the tray icon opens the tray menu instead of the app window.
The launcher entry or icon is wrong
Recent changelog entries list fixes for the desktop launcher association and a wrong icon on Ubuntu. Upgrade to the latest release first. If the entry still fails to appear, log out and back in so the desktop reloads its application list.
The tarball sits on a network share
Mattermost recommends a local drive for the desktop app and does not support network shares. If you extracted the tarball onto an NFS or SMB mount, move the folder to a local path such as ~/apps and start it from there.
Key takeaways
- The desktop app needs a Mattermost server URL to do anything
- The apt repository is my pick on Ubuntu 22.04 and later
- Snap and Flathub builds come from community maintainers
- The deb, rpm, AppImage and Flatpak files are labelled unofficial upstream
- Use dnf for a local rpm and uppercase -U for rpm upgrades
- Arch packages can trail the 6.3.1 release
- Rerun the apt setup script with UPDATE_GPG_KEY=yes after the GPG change
- Prefer apt or Flatpak over the AppImage on Ubuntu 24.04
- Version 6.3.1 carries security fixes
- Delete ~/.config/Mattermost to reset the client
Frequently asked questions
What is the easiest way to install Mattermost Desktop on Ubuntu?
Run Mattermost’s repository setup script, then sudo apt install mattermost-desktop. Updates then arrive through apt, which makes this route easier to maintain than a one-off download.
Does Mattermost Desktop work without a server?
No. The desktop app only connects to an existing Mattermost server, so you need the server URL from your admin or you must deploy a server yourself.
Is the Mattermost Snap package official?
No. The Snapcrafters community maintains it and the Snap Store page says upstream does not necessarily endorse it. The apt repository and tarball are the upstream routes.
Which Linux distros support the Mattermost desktop app?
Mattermost’s download page lists Ubuntu 22.04 or later. Other distros can run the official tarball or the unofficial rpm, AppImage and Flatpak builds. Arch packages it in the Extra repository.
How do I update Mattermost Desktop on Linux?
Use apt upgrade, snap refresh or flatpak update depending on how you installed it. The rpm, AppImage and tarball builds need a manual download of the newer release.
Why does the Mattermost AppImage fail on Ubuntu 24.04?
Ubuntu 24.04 restricts unprivileged user namespaces through AppArmor, which can break Electron’s sandbox inside an AppImage. Use the apt package or Flatpak instead of disabling the sandbox.
How do I uninstall Mattermost Desktop completely?
Remove the package with your package manager then delete ~/.config/Mattermost to clear configuration and session data. Flatpak users add the –delete-data flag to the uninstall command.
Conclusion
Mattermost install on Linux works best through the apt repository on Ubuntu 22.04 or later. Fedora, Arch and other distros can use the rpm, pacman, Flatpak or tarball routes. Every method needs a server URL. Version 6.3.1 carries security fixes, so check your release and update through the same method.