Privacy Policy

Effective July 30, 2026

This policy explains how Hanzi King handles information when you use the Android or web app.

Information stored on your device

Study progress, review schedules, streaks, XP, levels, daily-mission progress and claims, writing-practice totals, saved and weak cards, settings, quiz history, and custom flashcards are stored locally on your device. You can export, import, or reset this information from Settings.

Optional account and cloud sync

You may use Hanzi King without an account. If you register or continue with Google, Firebase Authentication and Google process your email address, account identifier, profile details, authentication tokens, verification status, and security metadata. Hanzi King stores your learning progress—including XP, missions, writing totals, streaks, sessions, and custom-card data—in Firebase Firestore so it can be restored on another device. Passwords and Google credentials are handled by their authentication providers and are not stored in the app’s own database.

Advertising

Hanzi King uses Google AdMob to display advertisements. Depending on device, region, consent, and Google settings, AdMob may process device identifiers, advertising identifiers, approximate location derived from an IP address, app interactions, diagnostics, and ad performance data. Where required, Google's consent platform asks for advertising choices before the app requests an ad, and Settings provides an Ad privacy choices entry point when Google requires one. Google acts under its own privacy terms.

Premium purchases

Premium purchases are processed by Google Play. Hanzi King receives product identifiers, purchase state, acknowledgement state, renewal status, purchase time, and entitlement availability so it can unlock Premium and restore access. The app does not receive or store your full payment-card or bank-account details. A one-way account identifier may be attached to a checkout request to help Google associate and protect the transaction. Premium feature-usage counts may be included in your optional Firebase learning-progress sync, but purchase ownership is checked with Google Play rather than granted from ordinary cloud-progress data.

Learning content, audio, and pronunciation practice

The app can download public Chinese character frequency data, stroke-order data, and pronunciation audio from third-party content delivery networks. Those providers receive ordinary network information such as your IP address and request details. If you choose Tap to Speak, Hanzi King requests microphone access and sends the spoken attempt to Android or your configured speech-recognition provider for transcription. Hanzi King does not store or upload the raw microphone recording itself; it stores only the returned transcript, score, attempt count, and related learning progress.

Custom cards

Custom drawings and notes stay on your device unless you sign in and use cloud sync. Do not place sensitive personal information in a custom card.

Retention and deletion

Local data remains until you reset the app, clear its storage, or uninstall it. Cloud data remains while your account is active. You can permanently delete your Firebase account and associated cloud learning data from Profile → Delete account. See the account deletion instructions.

Children

Hanzi King is a general-audience educational app and is not directed to children under 13. A parent or guardian should supervise use where local law requires it.

Security

Cloud traffic uses HTTPS and access is tied to Firebase Authentication. No online service is completely risk-free, so users should keep their device and account credentials secure.

Your choices

• Use the app entirely as a guest.
• Disable automatic learning-data updates in Settings.
• Export or reset local learning progress.
• Delete an account and cloud data from inside the app.
• Control advertising choices through Hanzi King Settings when available, as well as Android and Google settings.
• Restore or manage Premium purchases through Google Play.

Contact

For privacy questions, email ifl.customerstaff@gmail.com.