Web Flashcards Privacy Policy

Last updated: November 5, 2026

This policy covers Chinese Challenger Web Flashcards, the HSK flashcard study tool on chinesechallenger.com. The Chinese Challenger iPhone app has its own privacy policy.

What Data We Collect

Email address: used to create your account, send you one-time login links, and tie your purchases to your account
Study progress: which cards you have reviewed, how you rated each one, and when each card is next due
Purchase records: which decks you bought, the amount paid, and the order reference from our payment provider
Study preference: your chosen card direction (hanzi first or English first) is saved in your browser only

How Data Is Used

To log you in and keep you signed in
To unlock the decks you have bought, on any device
To schedule your reviews and show your progress
To handle refunds and respond to support requests

What We Do NOT Do

We do not receive or store your payment card details
We do not sell your data to third parties
We do not use your data for advertising, and Web Flashcards has no ad trackers
We do not send marketing email without your consent

Third-Party Services

Supabase stores your account, study progress and purchase records, and sends login emails. See supabase.com/privacy.
Paddle.com is our Merchant of Record and processes all payments. Paddle collects your payment and billing details (such as card, country and postcode for tax) under its own policy at paddle.com/legal/privacy.
Vercel hosts the website and may process standard request data such as IP addresses for security and reliability.

Cookies

We use only the cookies needed to keep you logged in. Paddle's checkout may set its own cookies to process your payment securely.

Data Retention and Deletion

We keep your account data while your account exists. To delete your account and all its study progress, email us at master@chinesechallenger.com from the address on the account. Paddle may keep transaction records as required for tax and accounting.

Your Rights

Depending on where you live, you may have the right to access, correct, export or delete your personal data. Contact us and we'll respond within 30 days.

Changes

We may update this policy from time to time. The date at the top shows the latest version.

Privacy Contact

For privacy questions, contact us at master@chinesechallenger.com.