The short version

Nearly everything this app remembers about you — progress, stats, theme — is kept in your browser's local storage, which is not a cookie and is never sent to a server on its own. An actual cookie is only ever set in one place: keeping you signed in, if you choose to sign in.

Local storage (not cookies)

Stored under keys like keigo-trainer-progress, keigo-trainer-scenario-progress, keigo-trainer-stats, keigo-trainer-explain-usage, and keigo-trainer-theme. If you sign in, one more key records that this device's local progress has already been merged into your account, so it isn't double-counted on a later sign-in.

Cookies (only if you sign in)

Supabase Auth sets a session cookie so the app can recognize you across visits without asking you to click the email link again every time. It's refreshed automatically in the background. No advertising or cross-site tracking cookies are set by this app, signed in or not.

Third-party cookies

None. There are no ad networks or analytics providers embedded in this app to set them.

Your controls

Clearing this site's data in your browser removes both local storage and the Supabase session cookie — you'll land back in guest, local-only mode. You can also clear just your progress from Settings without touching your sign-in.