pub upgrade

Upgrade is one of the commands of the pub tool. Learn more about pub.

$ pub upgrade [args] [dependencies]

Like pub get, pub upgrade gets dependencies. The difference is that pub upgrade ignores any existing lockfile, so that pub can get the latest versions of all 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. For example:

$ pub upgrade
Dependencies upgraded!

When pub upgrade upgrades dependency versions, it writes a lockfile to ensure that pub get will use the same versions of those dependencies. For application packages, check in the lockfile to source control; this ensures the application has the exact same versions of all dependencies for all developers and when deployed to production. For library packages, don’t check in the lockfile, because libraries are expected to work with a range of dependency versions.

If a lockfile already exists, pub upgrade ignores it and generates a new one from scratch, using the latest versions of all dependencies.

See the pub get documentation for more information on package resolution and the system package cache.

Upgrading specific dependencies

You can 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 test 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.

Getting a new dependency

If a dependency is added to the pubspec before pub upgrade is run, it gets the new dependency and any of its transitive dependencies, placing them in the .packages file. This is the same behavior as pub get.

Removing a dependency

If a dependency is removed from the pubspec before pub upgrade is run, it removes the dependency from the .packages file, thus making the dependency 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 pub get.

Upgrading while offline

If you don’t have network access, you can still run pub upgrade. Because pub downloads packages to a central cache shared by all packages on your system, it can often find previously downloaded packages without needing to use the network.

However, by default, pub upgrade tries to go online if you have any hosted dependencies, so that pub can detect newer versions of dependencies. If you don’t want pub to do that, pass it the --offline flag. In offline mode, pub looks only in your local package cache, trying to find a set of versions that work with your package from what’s already available.

Keep in mind that pub generates a lockfile. If the only version of some dependency in your cache happens to be old, offline pub upgrade locks your app to that old version. The next time you are online, you will likely want to run pub upgrade again to upgrade to a later version.


The pub upgrade command supports the pub get options.

For options that apply to all pub commands, see Global options.