Fuel currently supports English, Spanish, French, German, Dutch, Swedish, Korean, Japanese, Ukrainian, Russian, and Thai.

Apple Watch Setup and widgets can fall back to English for strings that do not have a translation yet.

02How to change language in Fuel

Fuel has an in-app language setting.

If you have never selected a language in Fuel, the app uses your device language when it is supported and falls back to English otherwise.

03How iOS per-app language interacts with Fuel

iOS can also assign a per-app language that differs from the system language.

If you change the Fuel language inside iOS Settings, Fuel will still use the in-app language you picked most recently.

Some features are gated by app language rather than device language, and may only support a subset of the languages above.

Use Notification Variations for the current list and eligibility rules for on-device notification rewrites on iOS 26 and later.

If Fuel looks partially translated, or switches language between screens, treat it as a settings and caching problem first.

If you still see inconsistent copy after those steps, contact us with screenshots and your iOS version.