Tenhou English UI is a Chrome add-on developed by mj.apply.sci that allows users to change the user interface text of the Tenhou HTML5 Web Client from Japanese to English. With this add-on, players can enjoy playing Tenhou and Ron2 in their preferred language.

The latest version of Tenhou English UI updates the original plugin from Mai. It also offers the option to use custom tilesets, which are labeled with Western numbers and letters or brightened with stronger colors.

This add-on supports multiple languages, including English, Français, Tiếng Việt, Polski, and Español. After installing the extension, users can visit the Tenhou or Ron2 websites to see the translated user interface in action.

Please note that this add-on is not compatible with the Flash client. Special thanks are given to Mai, Dimitrieh, TrollOfNova, Starfire, Kraków Chombo Club, and kvaps for their contributions to this project.