Translate abroad with roaming switched off.

Before you go

1. On Wi-Fi, download every language you will need (about 30 MB each).
2. On your iPhone, add the speech languages you want to speak in, so iOS can hear them offline: see how to let your iPhone hear another language, below.
3. Turn off mobile data for SofiLingo if you want to be certain: Settings → Mobile Data (Cellular in some regions), then switch SofiLingo off.

While you are away

Type a phrase and show the screen: that never needs a signal. Point the camera at a menu or sign: most languages are read on the phone.

When a scan needs a connection, the app says so and keeps the photo. It is in Saved scans with the others, and translates itself the next time you are on Wi-Fi, at the hotel or in a café.

Speaking and listening

Speech uses your iPhone's own recognition. With that language's speech pack installed it runs offline; without one, iOS sends the audio to Apple to transcribe, as dictation does, and that uses data. Live translate tells you when it cannot listen offline instead of quietly spending roaming data.

With mobile data switched off, the speech languages your iPhone cannot hear offline will not work at all. Typing is the fallback, and it works in every language.

Questions

Does SofiLingo use mobile data?

Not for translating: that happens on the phone. Scanning a language the phone cannot read, and speech without an offline speech pack, need a connection, and the app says so when they do.

What happens to a scan with no signal?

It is kept in Saved scans and translates itself the next time you are online.