Telegram works on message translation through its own servers

The new API schema data on the Telegram website indicates that in future versions of the messenger, translations will be made through the Telegram servers. In the current version of the application, translation on iOS is done via Apple Translator, and on Android — by direct requests to Google Translate. The language of the message is detected on-device. According to Durov's Code , Google Translate in Telegram for Android is used in a quirky way, with a workaround to not pay the service fee, as a temporary measure, while the messenger team is working on translation through their servers.

What technology will be used is still unknown. Language detection will most likely continue to be on-device.

source: @tginfo