Open a page written in Japanese, click one button, and Firefox rewrites it in English as you read it. The translation happens on your own device. Mozilla says the text being translated stays on your device, rather than being uploaded to a translation service.
When Firefox spots a page in a supported language that isn't your own, it offers to translate. Click Translate and the words change in place. The links and the address stay put, and the translation menu in the address bar has a Show original button that puts the page back.
Your text stays on your device
Mozilla built the feature on Bergamot, a translation research project that the EU paid for. It shipped in Firefox 118 in September 2023. The release note for that version says so in one line. "Unlike cloud-based alternatives, translation is done locally in Firefox, so that the text being translated does not leave your machine."
Mozilla announced local translation in Firefox for Android 127's June 2024 release notes, after a rollout that began in version 126. Japanese, Simplified Chinese and Korean came to the desktop in Firefox 135 in February 2025. Translation reached iPhone in December 2025 with Firefox for iOS 146. Mozilla added languages there in stages, starting with German, French and Japanese, then Spanish and Portuguese the following week.
the languages Firefox 135 added, local models on Android, on-device translation on iPhone and how the iPhone rollout went
A message from a foreign bank, a letter sitting in your webmail, the instructions on a government agency's website. Firefox translates the words on the page. The translation runs locally, so that task doesn't give a translation service a copy.
Firefox page translation and language settings
Download languages for offline use
You can download whole languages ahead of time in Firefox's translation settings. The screenshot shows an earlier Japanese language download. Mozilla keeps revising those files, so the size in that screenshot isn't a current download estimate. Once the languages needed for your translation are downloaded, Firefox can translate a page it already loaded without a connection. It downloads the needed files automatically when you first translate online.
The translation menu's gear button lets you always translate a language or tell Firefox to stop offering translations on a particular site. You can manage those choices in Firefox's settings. You can also remove a language when you want the space back. Mozilla's translation feature page lists the currently supported languages.
Mozilla on downloaded models and offline translation, Android translation rollout
How good is it
Rough but usable. The illustrated Japanese Wikipedia page about the internet comes back as readable English, with a few Japanese words left in place. One page can't tell you how another language or another kind of writing will come out, and none of it is worth leaning on for a contract.
You can also translate one piece of a page instead of all of it. Highlight the text, right-click, and choose the Translate Selection option. The translation shows up in a small box, and it stays on your computer like everything else.
