Vaadin Flow 3.1.0 is a feature release of the Java Framework for Vaadin 16 that includes a number of new features and enhancements.

No notable changes since 3.1.0.beta2.
All changes since 3.0

3.1 Feature Highlights

Automatic Node installation

• Available from Vaadin versions 14.2 and 16
• If no global or local Node installation is found Node will be automatically installed to ~/.vaadin
  • Only requires the first project to install as later can use the same installation
  • No need to have Node installed for CI
• Uses proxy data from
  • System properties
  • {project}/.npmrc
  • ~/.npmrc
  • Environment variables

pnpm is the default frontend package manager

• Now pnpm is used by default instead of npm
  • npm was still default in Vaadin 14.2 and 15
• No migration needed - pnpm is installed once to /.vaadin inside home folder. See differences here for more information about what has changed
• User specified local package.json dependencies are considered instead of "locked" dependencies coming from Vaadin (#8108)

Devmode is run as a separate thread to speed up server startup

• Allows server to continue startup parallel to Flow development mode process which runs pnpm/npm and webpack build
• The browser shows a white page that is automatically refreshed to open app once devmode process has finished
• As server is started up faster, there is no timeout from "run from IDE" or from server plugins

Minor improvements in 3.1

• API in UI for switching between direction RTL / LTR (document.dir)
• Flow 3.1 contains all improvements shipped in Flow 2.2, see release notes for detailed list.

Known Issues and Limitations in 3.1

• pnpm is not able to resolve dependencies to git commits with the "short" hash format. See details and workaround from #7406.

Deprecations since 3.0

• The enableInstallPrompt parameter for the @PWA annotation has been deprecated, as the install prompt will be removed an upcoming version and not shown anymore #8038

Incompatible Changes in 3.1

• The com.vaadin.flow.component.Direction class has been changed to an enum and the method getDirectionForLocale(java.util.Locale) has been removed.
• Some Flow internal classes related to frontend tooling installation & running have changes that are not backwards compatible. Nobody should be using these classes in their application code - in case you are, you should create an issue about what you're trying to achieve and why, so that a proper way to support that use case can be considered instead of relying on internal classes.