Privacy Policy
Last updated: 2026-05-21
This policy describes what mandarin.best collects, why we collect it, who processes it, and how you can exercise your rights. If anything is unclear, email us at support@mandarin.best.
Who we are
mandarin.best is an online Chinese learning platform for overseas learners, offering HSK and YCT vocabulary study and practice, KIDS Chinese picture book reading, and literacy assessment, available at mandarin.best. Operated by mandarin.best. Contact: support@mandarin.best.
Information we collect
Account data. When you create an account we store your email address and a salted bcrypt hash of your password. We never store passwords in plain text.
Study data. We record which words you have studied, your flashcard ratings, practice accuracy, and learning progress so we can personalize your study experience.
Billing data. When you purchase a subscription, Stripe handles the payment. We receive only a tokenised reference plus the last four digits of your card and your billing country. We never see your full card number.
Children's data. The KIDS module requires a parent or guardian to create the account and supervise use. We do not collect personal information from children without parental consent. Learning data (books read, character recognition, quiz results) is stored in association with the parent account.
How we use it
- To run your account, schedule reviews, and persist progress across devices
- To process payments and fulfil subscription orders
- To send you transactional email about your account and orders
- To improve the product
- To prevent abuse (rate limits, fraud detection on payment endpoints)
- To meet legal and tax obligations
Third-party processors
mandarin.best uses the following third parties to operate the service, each processing a defined slice of data under their own privacy policy.
| Processor | Purpose | Data shared |
|---|---|---|
| Vercel | Web and API hosting, CDN | IP address, request headers, HTTP access logs |
| Stripe | Payment checkout, subscription billing, refunds, tax | Email, billing address, last four digits of card, country |
| Cloudflare R2 | File storage (book illustrations, audio) | Image and audio files |
We do not sell your personal information to anyone. We do not share it with advertisers. We do not use it for cross-context behavioural advertising.
International transfers
Our processors operate in the United States and the Asia-Pacific region. Data may transit between these regions.
Your rights
You have the right to access, correct, export, and delete your personal data. To exercise these rights, sign in and use your account settings, or email support@mandarin.best. We will respond within 30 days. You can delete your account at any time. Once confirmed, we queue your data for deletion within 30 days. Some financial records are anonymised and retained for up to seven years to meet tax and accounting obligations.
Children
The KIDS module is intended for children under parent or guardian supervision. We do not knowingly collect personal information from children without parental consent. If you believe a child has created an account without parental consent, email support@mandarin.best and we will delete the account.
Security
- All connections use TLS 1.2 or higher
- Passwords stored as salted bcrypt hashes; we never see the plaintext
- Stripe handles card data; we do not store full card numbers
Changes to this policy
We update this policy when our processors, data flows, or obligations change. The date at the top reflects the most recent revision. Material changes are announced by email if you have an account.
Contact
Questions, complaints, and rights requests: support@mandarin.best. See also: Terms of Service