Bases¶

This reference details the available bases for snaps and the requirements for using them across the different snap types.

Base snaps¶

There are six supported base snaps:

Name	Description	Latest snapcraft track with support
core26	built from Ubuntu 26.04 LTS	9.x
core24	built from Ubuntu 24.04 LTS	8.x
core22	built from Ubuntu 22.04 LTS	8.x
core20	built from Ubuntu 20.04 LTS	8.x
core18	built from Ubuntu 18.04 ESM	7.x
core	built from Ubuntu 16.04 ESM, not to be confused with core16 (see below)	4.x
bare	an empty base that’s useful with fully statically linked snaps and when testing	8.x

Older releases of core were occasionally referred to as core 16, but core and core16 are two distinct packages.

Warning

core16 is not a supported base. With no stable release, its beta and candidate releases are classed as experimental.

The Support schedule details the support timeline for ESM releases.

The base key in a project file defines:

The base must be defined in all snaps except for base, snapd, and kernel snaps.

The base must be a supported base.

The build-base key defines the environment where the snap will be built.

build-base can only be defined for the following scenarios:

build-base must be a supported base when base: bare is defined.

build-base must be devel when base is unstable.

Unstable means that the base snap has not been released to the stable channel.

Snaps with a devel build base must have a grade of devel and cannot be promoted to stable or candidate channels.

build-base must be a supported base when type: kernel is defined.

See How to build a kernel snap for details on how to use build-base for kernel snaps.