Privacy policy
Last updated: October 13, 2026. This policy covers the Kyou Kanji Android app, the Kyou Kanji web app and this website.
The short version
Kyou Kanji works without an account, and then your study progress stays on your own device. Accounts are optional: if you create one, we store your email address and your study progress so you can use them on your other devices. There are no ads and no analytics or tracking.
Your study progress
- Android app: progress is saved in the app's private storage on your phone. If you've turned on Android's backup, Android may include it in your backup to your Google account. That backup is handled by Google under its own privacy policy, and you can turn it off in your phone's settings.
- Web app: progress is saved in your browser's storage on your device. It isn't sent to us unless you sign in to an account. Clearing your browser's site data deletes it.
- Backup files: when you choose to export a backup, the app creates a file and you decide where it goes. We never receive it.
Accounts (optional)
If you create an account, we store:
- Your email address, used to sign in. We only email you when you ask to reset your password, and we never share it for marketing.
- Your password, stored only as a secure one-way hash. We can't read it.
- Your study progress: which kanji you've studied and when they're due, your daily review counts, your streak and your study settings.
- Password reset codes, if you ask to reset your password: a one-time code that stops working after an hour, stored only as a secure hash.
- A record of each device you're signed in on: whether it's the Android app or a web browser, and when it was last used, so it can stay signed in.
This is used only to sign you in and keep your progress in sync between your devices. It's stored with Cloudflare, which hosts Kyou Kanji. If you ask to reset your password, your email address is passed to Resend, the service that delivers that email for us. We don't sell any of it or share it with anyone else, and we don't use it for advertising.
Deleting your account: in either app, go to Settings, then Account, then Delete account. Your account and the progress saved to it are deleted right away, and every device is signed out. Progress already on a device stays on that device. If you can't sign in, email us at the address below and we'll delete it for you.
Signing out stops syncing; your progress stays on that device.
Notifications
If you turn on the daily reminder in the Android app, the reminder is scheduled on your phone. No data is sent anywhere to do this.
Ratings
The Android app may occasionally ask you to rate it, using Google Play's in-app review feature. Google handles that request and your rating under its own privacy policy; we don't receive any information about whether you rated the app.
The website
Like any website, the server that delivers the web app receives standard technical information, such as your IP address and browser type, so it can send you the page and protect against abuse. We don't use this to identify you, and we don't use cookies. If you sign in, the web app keeps your sign-in in your browser's storage.
Children
Kyou Kanji isn't directed at children under 13, and accounts are for people 13 and older. We don't knowingly collect information from children under 13.
Changes
If we change what we collect or how we use it, we'll update this policy before the change takes effect and change the date at the top.
Contact
Questions about this policy: gold1n0labs@gmail.com