Snaps and Flatpaks

Why other formats exist

Debs from the Ubuntu archive are tied to your Ubuntu release: on an LTS, an app keeps roughly the version it shipped with, plus fixes, for years. That’s ideal for system tools, less so for a desktop app that improves every month. And a deb has full access to everything on your system ¹.

Snaps and Flatpaks solve both. Each app comes straight from its publisher, bundled with most of what it needs, so it can be updated independently of your release, and each runs in a sandbox that limits what it can reach ^{1 2}. The cost is disk space: bundled libraries mean each app is bigger than its deb ¹.

Snaps vs debs

Snaps are Canonical’s format, built into Ubuntu; the App Center shows snaps by default ¹. Firefox on Ubuntu is one. Ubuntu’s own comparison ¹:

When an app comes both ways, Ubuntu generally recommends the snap, especially from a third-party publisher: it’s usually newer and better contained ¹. Some snaps, mostly developer tools, use classic confinement, which means no sandbox; the Snap Store team reviews those by hand ¹.

Everyday snap commands

snap list shows what’s installed. The format, from the snap documentation ³:

Name     Version    Rev    Tracking       Publisher    Notes
core22   20231123   1033   latest/stable  canonical✓   base
firefox  120.0.1-1  3504   latest/stable  mozilla✓     -
snapd    2.60.4     20290  latest/stable  canonical✓   snapd

Version is the app’s own version; Rev is the store’s revision number; Tracking is the channel it follows; a ✓ marks a verified publisher; base marks a base snap, the shared runtime other snaps build on ³. On 26.04 you’ll see newer numbers, and bases like core24 and core26 ¹.

me@garden-laptop:~$ snap find "media player"
me@garden-laptop:~$ snap info vlc
me@garden-laptop:~$ sudo snap install vlc
me@garden-laptop:~$ sudo snap remove vlc

snap find searches the Snap Store; snap info describes a snap and lists its channels ³. A channel is a release track: latest/stable by default, with candidate, beta, and edge for less-tested versions. sudo snap install --channel=beta name picks another, and sudo snap switch --channel=stable name moves back ³.

Updates are automatic. snapd checks four times a day and applies new revisions on its own ⁴. snap refresh --time shows the schedule; sudo snap refresh updates everything now; and snap refresh --hold=24h firefox postpones one snap’s updates, for a set time or forever ⁴.

If an update breaks something, go back:

me@garden-laptop:~$ sudo snap revert vlc
vlc reverted to 3.0.5-1

That’s the snap tutorial’s own example. The previous revision is kept, and the snap won’t update to the revision you reverted from; it updates again when a newer one is published ³.

Permissions are interfaces: snap connections vlc lists what the snap can reach (audio, camera, your home folder), and snap connect vlc:camera grants one that isn’t connected ³. In the desktop, Settings, Apps does the same ¹. A snap’s own data lives under ~/snap/<name>/ ³.

Flatpaks and Flathub

Flatpak is another sandboxed format, used across many distributions, and Flathub is its main app store. Ubuntu doesn’t set it up by default, and the App Center doesn’t install Flatpaks ⁵. To add it ⁵:

me@garden-laptop:~$ sudo apt install flatpak
me@garden-laptop:~$ flatpak remote-add --if-not-exists flathub https://dl.flathub.org/repo/flathub.flatpakrepo

then restart. To install Flatpaks from a graphical store too, Flathub suggests sudo apt install gnome-software-plugin-flatpak, which adds a separate “Software” app alongside the App Center ⁵.

Flatpak names apps with reverse-domain IDs, like org.gimp.GIMP ²:

me@garden-laptop:~$ flatpak search gimp
me@garden-laptop:~$ flatpak install flathub org.gimp.GIMP
me@garden-laptop:~$ flatpak run org.gimp.GIMP
me@garden-laptop:~$ flatpak list --app
me@garden-laptop:~$ flatpak update
me@garden-laptop:~$ flatpak uninstall org.gimp.GIMP
me@garden-laptop:~$ flatpak uninstall --unused

Apps need a runtime, a shared base like a snap’s base snap, which is installed alongside the first app that needs it. uninstall --unused removes runtimes nothing uses any more ². Installs are system-wide by default; --user installs just for you ². Run flatpak update now and then to update Flatpak apps and runtimes ²; a Software app with the Flatpak plugin can do it too.

Which to choose

A workable set of rules:

• Command-line tools and system software: apt. htop, tree, rsync, git, servers. They fit the system and update with it.
• Desktop apps: whatever gives you a current, sandboxed version. On Ubuntu that’s usually the snap, which the App Center shows first ¹; Flathub is the alternative when an app isn’t a snap, or its Flatpak is the one the developers maintain.
• Third-party debs and PPAs: last. They run unsandboxed and can break release upgrades ⁶.

Don’t install the same app two ways at once; you’ll get two icons, two sets of settings, and confusion about which one is running.

Your turn

So

Snaps and Flatpaks deliver apps straight from their publishers, bundled and usually sandboxed, at the cost of disk space. Snaps are built into Ubuntu: snap list, find, info, install, channels, automatic refreshes four times a day, snap revert when an update misbehaves, and snap connections for permissions. Flatpaks need sudo apt install flatpak and the Flathub remote, then flatpak install, run, update, and uninstall --unused. Use apt for the system and command-line tools, a snap or Flatpak for desktop apps, and third-party debs only as a last resort.