Privacy policy
Last updated: October 29, 2026
This site is a study notebook for 《汉语教程》 run by Ivan Leovandi. We only store the data needed for its features to work. We show no ads and never sell or share your data.
Data we store
Without signing in: your display preferences, stars, notes and own words are stored only in this browser (localStorage) and are not sent to any server.
When signed in: your email address (and your name and profile picture if you sign in with Google), plus your stars, notes and own words, are stored in our database so they sync across your devices.
Feedback: the type and text of your message, the contact you choose to give (optional), the page and language you were using, and browser information, so the problem can be traced.
Premium purchase: the screenshot of your payment, your note, your account email and the status of your request. Proofs sit in private storage that only the site owner can open, and are used only to check the payment.
How data is used
Only to provide sign-in and syncing, and to read and act on feedback. It is not used for advertising or marketing.
Cookies and browser storage
A sign-in session cookie (from Supabase) keeps you signed in, and the hy.lang cookie remembers your chosen language. localStorage keeps display preferences and guest data. There are no analytics or third-party tracking cookies.
Service providers
The site is hosted on Vercel; the database and sign-in use Supabase. If you sign in with Google, Google also processes that sign-in. Data may be processed on servers outside your country.
Payments are made in Alipay; we never receive card or bank details. When you send proof of payment, the site owner is notified by email through Resend.
Security
Each account can only read and change its own data; the database enforces this. Feedback can only be read by the site owner.
Your rights
You can sign out at any time, and delete guest data by clearing this site's data in your browser. To request a copy of your data or to delete your account and all its data, contact us on WeChat. Requests are handled as soon as possible.
Changes
This policy may be updated from time to time. The date at the top shows the latest change.
Contact
WeChat: efundl