For example you may want to log the Vaadin version to the server log at start time, or you want to see whether the vaadin version v-bump has been taken into effect in your project.

From Java

For Vaadin 14: You can look up the NpmPackage annotation from the VaadinCoreShrinkWrap class to learn the Vaadin version. This however only works with Vaadin 14: newer Vaadin no longer contains the VaadinCoreShrinkWrap class.

For Vaadin 23 and higher: you can load the META-INF/maven/com.vaadin/vaadin-core/pom.properties resource file as Properties; the version is stored in the "version" key.

Tip: Or simply use VaadinVersion.get from karibu-tools does.

From JavaScript

This one is trickier.

In both dev mode and in production

For Vaadin 20+ the Vaadin component versions is usually in sync with the version of Vaadin itself. Therefore, running customElements.get('vaadin-button').version should return something like "21.0.2" which should exactly match the Vaadin version.

Note: there are exceptions: e.g. for Vaadin 23.3.33 the Vaadin Button returns 23.3.30

Vaadin 14: Unfortunately, this doesn’t work since customElements.get('vaadin-button').version will print something like "2.4.0" and you have to figure out the Vaadin version from that somehow.

One way would be to realize that certain Vaadin version pulls in certain Vaadin Button version, which would make the Vaadin Button version a kind of indicator of the Vaadin version itself. For example Vaadin 14.7.1 pulls in Vaadin Button 2.4.0. To do that, take a look at the @NpmPackage(value = "@vaadin/vaadin-button", version = "2.4.0") annotation present on the Java Button class (or rather GeneratedVaadinButton) and from that you can see the Button version which you should expect on the client-side as well. That being said, older/newer Vaadin versions might pull in the same Vaadin Button 2.4.0 and thus it’s definitely not a clear indicator of Vaadin version.

There’s window.Vaadin and window.Vaadin.Flow object but neither of those seem to be able to provide the version. You can only learn whether you’re running production mode or not, by querying window.Vaadin.developmentMode.

In dev mode

• In Vaadin 22+ the dev mode gizmo will now clearly show Vaadin version.

Other than that, the dev mode doesn’t provide more information on Vaadin version than the production mode does.