Privacy Policy

Last updated: March 13, 2026

HanziForge ("we," "us," or "our") operates the HanziForge web application at hanziforge.com. This Privacy Policy explains what information we collect, how we use it, and the choices you have regarding your data.

1. Information We Collect

Account Information: When you register, we collect your name and email address. If you sign in with Google OAuth, we receive your name, email, and profile picture from Google.

Study Data: We store vocabulary lists, flashcard review history, reading progress, writing practice data, grammar exercise results, and related learning activity you generate while using HanziForge.

Payment Information: Subscription payments are processed by Stripe. We do not store your credit card number, bank account details, or other payment credentials on our servers. Stripe may collect information necessary to process your payment in accordance with their own privacy policy.

Usage Data: We collect basic usage information such as pages visited, features used, and session duration to improve the application.

2. How We Use Your Information

• Providing and maintaining the HanziForge service
• Personalizing your learning experience (e.g., SRS scheduling, AI-generated content)
• Processing subscriptions and payments through Stripe
• Sending essential account notifications (e.g., password resets, billing receipts)
• Improving application features and fixing issues
• Enforcing our Terms of Service

We do not sell your personal information to third parties.

3. Cookies and Sessions

HanziForge uses a session cookie managed by NextAuth to keep you signed in. This cookie is essential for the application to function and does not track you across other websites. We do not use advertising or third-party tracking cookies.

4. Third-Party Services

We use the following third-party services:

• Stripe — Payment processing. Stripe collects and processes payment data under their own privacy policy.
• Google OAuth — Optional sign-in. When you choose to sign in with Google, we receive basic profile information as described above.

5. Data Retention

We retain your account and study data for as long as your account is active. If you delete your account, all personal data and study history are permanently removed from our systems within 30 days. Anonymized, aggregated data that cannot identify you may be retained for analytics purposes.

6. Your Rights

You have the right to:

• Access and view the personal data we hold about you
• Correct inaccurate information in your account settings
• Delete your account and all associated data through the Account Settings page
• Request a copy of your data by contacting us

7. Data Security

We use industry-standard measures to protect your data, including encrypted connections (HTTPS), secure password hashing, and access controls. However, no method of transmission over the Internet is completely secure, and we cannot guarantee absolute security.

8. Children's Privacy

HanziForge is not directed at children under 13. We do not knowingly collect personal information from children under 13. If you believe a child has provided us with personal data, please contact us and we will remove it promptly.

9. Changes to This Policy

We may update this Privacy Policy from time to time. When we make significant changes, we will update the "Last updated" date at the top of this page. We encourage you to review this policy periodically.

10. Contact Us