Machine translation has often relied on sending text to powerful servers. As models have grown more efficient, useful translation now runs directly on phones and laptops, turning text and even speech from one language to another without an internet connection.
Keeping the work on the device means private messages never leave it and translation keeps working on a plane or abroad without a signal. On-device models are smaller than their cloud counterparts, so they can be less fluent with rare languages or specialised terms, but for everyday travel and reading the gap has narrowed enough to be genuinely practical.