Upgrade is one of the commands of the pub tool. Learn more about pub.
$ pub upgrade [dependencies...]
Without any additional arguments,
pub upgrade gets the latest versions of
all the dependencies listed in the
pubspec.yaml file in the
current working directory, as well as their transitive
dependencies, to the
directory located next to the pubspec. For example:
$ pub upgrade Dependencies upgraded!
pub upgrade upgrades dependency versions, it writes a
lockfile to ensure that future
gets will use the same versions of those dependencies.
Application packages should check in the lockfile to source control; this
ensures the application will use the exact same versions of all dependencies for
all developers and when deployed to production. Library packages should not
check in the lockfile, though, since they’re expected to work with a range of
If a lockfile already exists,
pub upgrade ignores it and generates a new
one from scratch using the latest versions of all dependencies. This is the
primary difference between
pub upgrade and
pub get, which always tries to
get the dependency versions specified in the existing lockfile.
It’s possible to tell
pub upgrade to upgrade specific dependencies to the
latest version while leaving the rest of the dependencies alone as much as
possible. For example:
$ pub upgrade unittest args Dependencies upgraded!
Upgrading a dependency upgrades its transitive dependencies to their latest versions as well. Usually, no other dependencies are updated; they stay at the versions that are locked in the lockfile. However, if the requested upgrades cause incompatibilities with these locked versions, they are selectively unlocked until a compatible set of versions is found.
If a dependency is added to the pubspec before
pub upgrade is run, it gets
the new dependency and any of its transitive dependencies and places them in
packages directory. This is the same behavior as
If a dependency is removed from the pubspec before
pub upgrade is run, it
removes the dependency from the
packages directory, thus making it
unavailable for importing. Any transitive dependencies of the removed dependency
are also removed, as long as no remaining immediate dependencies also depend
on them. This is the same behavior as
If you don’t have network access, you can still run
pub upgrade. Since pub
downloads packages to a central cache shared by all packages on your system, it
can often find previously-downloaded packages there without needing to hit the
However, by default, pub always tries to go online when you upgrade if you
have any hosted dependencies so that it can see if newer versions of them are
available. If you don’t want it to do that, pass the
--offline flag when
running pub. In this mode, it only looks in your local package cache and
tries to find a set of versions that work with your package from what’s already
Keep in mind that pub will generate a lockfile after it does this. If the
only version of some dependency in your cache happens to be old, this locks
your app to that version. The next time you are online, you will likely want to
pub upgrade again to upgrade to a later version.
For options that apply to all pub commands, see Global options.