HanziGraph does not collect any of your data by default. Unless you create an account, all of the data stays locally on your device. Server logs are only retained for 90 days for debugging purposes, then deleted. There are no ads or 3rd party analytics tools used. The site is hosted with Firebase.
If you choose to create an account, your email address and password (or just email address if you use Sign in with Google) are saved. When you have an account, any flashcards you make and your study stats are saved. No other data is collected.
HanziGraph is free and open source. All code is available on GitHub.
Deleting an account
If you made an account and wish to delete it, simply log in and push the button below. Your account will be deleted immediately. This cannot be undone.