What this extension holds, where it holds it, and what leaves your machine. Last updated 25 August 2026.
With no account and no optional feature switched on, nothing leaves your browser on its own. There is no analytics, no telemetry, and no crash reporting. Only four things ever send anything, and all four are buttons you press. Two are the translation features below. The third is the flag that reports a wrong word. The fourth is the feedback box in settings.
Reading history is sensitive, so the stored shape is deliberately narrow. The extension records the hostname a word was met on, and keeps it on that machine. It never records page addresses, page titles, or the text of any page you visit.
An account is optional and off unless you make one. It exists so your progress reaches your other browsers. When you have one, these are copied to the server:
Hostnames are not on that list and never leave the machine they were seen on. The stats page can still say where you met a word, for that browser. It is the same trade as the count of times a word has been on screen. That is also kept locally.
Only your own account can read your data. The database enforces that, not the application. Every row is tied to a user id, and every rule checks it.
The server is Supabase, acting as a data processor. Nothing is sold, shared, or used for advertising. Nothing is used to train anything.
In the extension, open Progress, then Settings, then Your account, then Delete. This removes your account and everything attached to it. It cannot be undone, and it does not need to go through us.
To remove what is on your machine, use Reset in the same settings page, or uninstall the extension.
Off by default. Turn it on and the first choice is Chrome's own translator, which runs on your computer. That sentence goes nowhere.
The other two choices do send it. DeepL, or the model you have a key for, gets that one sentence and nothing else. Both skip the sites on your blocked list. Translations are cached, so a sentence is only ever sent once.
Off by default, and the same shape. Chrome's own model answers on your computer. Pick a provider instead and two things go to them: the word, and the sentence it appeared in. Your own key, straight from your browser to them. Answers are cached.
Chrome's models need a recent Chrome and a fairly large computer. Where they do not run, the extension says so rather than sending your text somewhere you did not choose. Nothing here is needed for the extension to work.
Optional, and only when you press it. You paste a WaniKani read-only token and it is sent to WaniKani to ask what your account already knows. The token is used for that one request and not stored.
Nothing about you goes anywhere else. What comes back is a list of words. It is matched against this library on your own machine, exactly as an imported file would be.
Every substituted word has a small flag in the corner of its card. It sends the Japanese word and the English word it replaced. It also sends what kind of mistake you think it is, how sure you are, and whatever you type.
It does not send the page, the address, the site, or the sentence. If the sentence matters, type it, so that what you send is what you have read. A report is attached to your account only if you are signed in. Either way it carries a random id for the installation. Nothing is sent unless you press Send.
The About tab in settings has a box for anything else you want to say. It sends what you type, and which of three kinds you picked.
It does not send the page, the address, the site, or your email address. Feedback is attached to your account only if you are signed in. Either way it carries a random id for the installation. There is no reply to it, so email [email protected] if you want one.
This is not directed at children under 13, and accounts are not knowingly created for them.
If what is collected ever changes, this page changes with it and the date above moves. Material changes will be noted in the extension's release notes.
Questions, or a request about your data, go to [email protected].