Privacy Policy
Last updated: July 18, 2026
Todoku is a free tool that measures how much of a Japanese text you can understand. This policy explains what data we handle and why. The short version: we collect as little as possible, we don't sell your data, and there are no ads.
What we collect
If you sign in with Google (optional), we receive and store your name, email address, and profile picture. We use this only to recognize your account. Signing in is not required to use Todoku.
On your device.Your JLPT level and your list of "known" words are stored in your browser's localStorage. They stay on your device and are not part of any account unless you choose to export them.
Text you analyze. Subtitle files and lyrics you submit are processed in memory to compute your comprehension score and are then discarded. We do not store, log, or share the content you analyze.
Cookies
If you sign in, we set a session cookie so you stay logged in. We do not use advertising or third-party tracking cookies.
Service providers
We rely on a small number of providers to run Todoku:
- • Google — sign-in (OAuth).
- • Vercel — hosting and serving the app.
- • Neon — the database that stores accounts.
These providers process data only to provide their service to us. We do not sell or rent your personal data to anyone.
Keeping and deleting your data
We keep your account data for as long as your account exists. You can sign out at any time from Settings. To delete your account and associated data, email us at ijoob@umich.edu and we'll remove it.
To clear the data stored on your device, use "Clear vocab database" in Settings, or clear your browser storage for this site.
Children
Todoku is not directed to children under 13, and we do not knowingly collect personal information from them.
Changes
We may update this policy from time to time. Material changes will be reflected by the "last updated" date above.
Contact
Questions about privacy? Email ijoob@umich.edu.