The OneSignal SDK will automatically detect the language set on the device/browser.
Limited to Push Notifications
Message Localization is limited to push notifications only at this time. To target emails and in-app messages by language, you must create Segments for the language to target each one individually.
The OneSignal dashboard and API makes English the default language for all new messages, but you can use any language you desire in this field. Think of "English" as "Default". For example if you enter a Spanish message into the "English" field, then all users will get the notification in Spanish.
If you want to send a single message in more than one language, you can add languages by clicking the pencil in Sending Notifications.. To learn more about this, please see
"English" (or "en" with the API) is the Default language. Think of this as default.
To send a notification without English, you can put your desired language in the English field and all devices will get the desired language.
For example, if you want all notifications to have a Spanish language, just put the Spanish message in the English field or "en" on the API. All users will get the Spanish message.
Support for RTL is handled by the Operating System level so it should be supported depending on the language and the user's phone settings.
If you do not see the language you want to support on our list or you allow users to set their own language, then you will need to differentiate the users and target separately.
If you track this data in your CRM or Database, you can target via our API as well. See Internal Database, DMP, & CRM.
The following are languages supported by OneSignal: