--- title: "Chrome built-in translator API extension · NoaLingua" description: "Chrome 138 added an on-device translation model. NoaLingua uses it first, falls back in a fixed order, and says which source produced each line." url: "https://noalingua.com/answers/chrome-built-in-translator/" language: "en" modified: "2026-09-08" license: "CC BY 4.0 — https://creativecommons.org/licenses/by/4.0/" --- Answer # How NoaLingua uses Chrome’s on-device translator First in a chain of four, and why it is first Chrome 138 added a translation model that runs on your own machine. NoaLingua tries it first for your language pair, because it is instant, works offline, and translates a sentence the extension assembled itself — so it has no caption-boundary errors. Short answer On-device first, because it is instant, offline and free of boundary errors. Three named fallbacks after it. On-device is first because it is instant, offline and translates a sentence NoaLingua assembled itself. YouTube’s translation uses a request the player makes anyway, so no new third party sees the text. MyMemory is the only source that sends sentence text off your device, which is why it sits behind its own checkbox and never appears in the fallback chain. ### What "genuinely ready" means, and why it matters Chrome does not have a model for every pair, and where it does the model may still be downloading. Treating "the API exists" as "the model is ready" is how an extension produces a blank line instead of a translation. It is also why the minimum is Chrome 138: that is the first release carrying the on-device Translator API the extension depends on. There is no Firefox or Safari build, because there is no equivalent to depend on. Get NoaLingua — free, and every feature included Dual subtitles on YouTube and Netflix, clickable words on any page and in any PDF, shadowing and spaced review — 28 languages, no account, and your deck stays on your own machine. [Add to Chrome — Free Add to Chrome](https://chromewebstore.google.com/detail/ocimolffhgpeeoifjpjhgikgfbnmlkdh) Opens the Chrome Web Store listing **NoaLingua — beyond dual subs: video, web, PDF** — free, no account, Chrome 138 or newer. - **Free** — every feature, not a trial - **No account** — nothing to sign up for - **Two dropdowns** — that is the whole setup ## More questions people ask NoaLingua Do I need to configure the on-device model? No. If Chrome has a model ready for your pair it is used automatically. If it does not, the chain falls through to the next source without you having to do anything. Does anything leave my machine when on-device translation is used? No. That is the point of it being first. Sentence text only leaves the device if you switch translation to Cloud yourself. Which pairs does Chrome not have a model for? Chrome does not publish that per language, so the coverage matrix marks it unverified rather than guessing. English to Serbian is one confirmed gap, which is why YouTube’s own caption translation matters as a safety net. ## Where this is documented on NoaLingua [What leaves the device, and when The precise list, each item with the setting that governs it.](https://noalingua.com/features/offline-and-privacy/)[Where the translation lands Sentences rebuilt before translation, and twelve translated ahead of you.](https://noalingua.com/features/youtube-dual-subtitles/)[The Chrome version requirement Why 138 is the floor, and what Chrome asks for at install.](https://noalingua.com/download/) ### Related NoaLingua answers - [Can I translate subtitles without sending them to a server?](https://noalingua.com/answers/translate-without-a-server/) - [Is there a Chrome extension with an offline dictionary?](https://noalingua.com/answers/offline-dictionary-chrome-extension/) - [Is there a language learning extension that needs no account?](https://noalingua.com/answers/language-learning-without-an-account/) ## Try it on the next thing you were going to watch anyway. Free, with every feature. No account, nothing to cancel, and your deck stays on your machine. [Add to Chrome — Free Add to Chrome](https://chromewebstore.google.com/detail/ocimolffhgpeeoifjpjhgikgfbnmlkdh) Opens the Chrome Web Store listing **NoaLingua — beyond dual subs: video, web, PDF** — free, no account, Chrome 138 or newer. - [Free, and not a trial Every feature on the free plan — both PDF modes, shadowing, all 30 practice formats.](https://noalingua.com/pricing/) - [No account, no email Nothing to sign up for and nothing to cancel. There is no login screen at all.](https://noalingua.com/privacy/) - [Two dropdowns to set up Pick what you are learning and what you want translations in. That is the whole setup.](https://noalingua.com/getting-started/) - [Your words stay yours Export to Anki, CSV, a spreadsheet or a full JSON profile — free on every plan.](https://noalingua.com/docs/export-import/) [What happens after you install](https://noalingua.com/getting-started/) · [Pricing](https://noalingua.com/pricing/) · [What it cannot do](https://noalingua.com/limits/)