Translation is usually a one-way door: the app guesses your mother tongue and everything lands in it. Before Babel opens the other direction. You choose the language you want to read messages in — often the language you are learning — download a language pack, and every incoming message is rendered in it, in the bubble where the text always was.

Nothing else in the app moves. Same chat list, same bubbles, same replies. Only the text changes, converted on the phone, offline, with no server in the loop.

This is how the mode works, why it is built around language packs instead of a translation API, and the three bugs that only appeared once the pipeline ran on real conversations.

What "in place" means

Most translation features add something: a second bubble, a "translated" section under the message, a spinner, a language label. Every one of those is a reminder that you are reading a translation, and every one of them changes the rhythm of a chat.

Before Babel adds nothing.…