Translations

1. Add the languages you need under Quick start.
2. Switch the preview to each language, select any message, and use Translate to override its text.
3. Check errors, long button labels, registration, password reset, and legal links in each language.
4. Export. If you need a text diff, the message bundles are in login/messages/.
5. In the target realm, turn on internationalization and enable the same languages under Realm settings → Localization.
6. Sign in fresh through your app and switch languages there.

The editor only overrides theme messages, it doesn't touch realm settings, so step 5 is still on you. Anything you didn't override keeps Keycloak's own translation. Email content is a separate theme type and isn't covered here.