1. Who we are

Baozi is an app for learning Chinese characters and HSK vocabulary. It is available as an iOS app, as a web app at app.hsk.cards, as a browser extension for Chrome and on the website baohsk.com (together, the “Service”). The Service is run by Ivan Guliaev, an individual entrepreneur based in Bishkek, Kyrgyzstan (“we”, “us”). For any question about your data, write to [email protected].

2. What we collect

You can study without an account. Without signing in, your progress stays on your device and we receive nothing except the technical data described below.

• Account data. If you sign in with email, we store your email address. If you sign in with Apple or Google, we store the account identifier that service gives us and the email address it shares (with Apple this can be a private relay address). If you choose to share your name with Apple, we store it to show on your account. We also keep a record of your sign-in sessions (device type, time).
• Learning progress. Which words you have studied, your answers and review history, streaks, achievements and app settings. When you are signed in, this is synced between your devices.
• Emails and messages. We use your email address for service emails about your account: when a trial starts and ends, and when Pro turns on or is about to end. Only if you turn on “Progress and tips by email” in Settings do we also send progress summaries, study tips and offers for Pro; every such email has an unsubscribe link. We store that setting and a record of which emails were sent.
• Usage events. Actions inside the app, such as “round started” or “pricing screen opened”, with non-identifying details. They are stored on our own server. We do not use third-party analytics or advertising SDKs, and we do not track you across other companies’ apps or websites.
• Purchases. If you buy a subscription, the payment is handled by the App Store, by Freemius on the web, or by another payment provider where the store offers one. We receive the plan, price, dates, status and a transaction or license identifier, never your card details.
• Technical data. Our servers log IP addresses, device or browser information and request times to run and protect the Service.
• Speaking practice. “Say it” listens through your microphone only while you speak, and only to draw your pitch on your device. By default nothing is recorded or stored: our server receives just a short list of numbers describing the pitch line, never audio. If you tap “Detailed check”, that one short recording and the target word are sent to an external pronunciation-check service to score your pronunciation; we do not keep it, and it goes with an anonymous code, not your name or email. You can keep the last take on your screen to play it back, and it is gone when you close the sheet.
• Writing checks. When you request a writing check, your text, the task, and earlier scores and feedback are sent to an AI service for assessment. The request does not include your account name or email, but personal details you write in the text are included. Do not enter information you do not want to share. Baozi saves the checked text and feedback with your account in “My writing”; you can delete a saved text there, and saved texts are removed when your account is deleted. Unsubmitted drafts stay on your device. In the iOS, web and Android apps, we ask for your permission before your first writing check and separately before your first detailed pronunciation check on this device and account. Declining leaves the text or recording on the device and does not prevent other study activities.
• Live conversations. In “Live conversations” and “Free conversation”, you talk with an AI character in Chinese, turn by turn: you record a line (up to 30 seconds) and send it. The recording and the text of the earlier lines are sent through our server to external AI services that recognize what you said, write the character’s reply and voice it; the pronunciation of your line is checked automatically. External providers may be used for the conversation. Your account name and email are not sent. Personal details you say during the conversation (such as your name, city, or job in the “About you” topic) are received by the AI services; do not share information you prefer to keep private. By default, neither your voice nor the text of the conversation is stored: our server keeps only the conversation’s time, the chosen topic and the number of lines, to count your lines (free: 12 lines; Pro: up to 600 lines in any 30 days; Super: up to 300 lines a day; current limits are shown in the app). Before your first conversation on a device, the app asks for your permission (“Talk with AI?”); declining does not prevent other study activities.
• Ask Bao. The AI helper is off by default; you turn it on in Settings. When you ask Bao a question or ask why an answer was wrong, your question, the task it refers to, the earlier messages of that chat and a short summary of your progress (level, streak, the words you find hardest) are sent to an external AI service for an answer. Your account name and email are not sent, but personal details you write in a question are sent with it. If you mention something about yourself that helps your study (such as a goal or an exam date), Bao may save a short note about it (at most 10) and use it in later answers. You can see the notes in Settings (“What Bao remembers about you”) and delete them one by one or all at once; they are also deleted with your account. Your questions and the answers are not stored with your account; to count your questions, we keep only the kind and time of each request, for 30 days.
• Shared recordings (optional, off by default). If you are signed in and turn on “Help improve tone training” (in Settings, in Say it after your first try, or in the conversation permission dialog), we keep your Say it recordings and conversation recordings from then on. For Say it, we keep each recording together with the word, pitch measurements, check results, and take details (device type, browser, app language). For conversations, we keep the audio stretches where you spoke into the microphone and a text transcript of both sides with timestamps, linked to your account ID without your name or email. Recordings and transcripts are stored on our server for your region (in Russia for Russian users; in the EU for others) and used to improve pronunciation checks and speech recognition; our team and a Chinese teacher listen to and read them. They are not used to identify anyone, shared with anyone else, or used for advertising. You can turn the switch off in Settings at any time to stop saving new recordings. Stored recordings and transcripts are kept for up to 24 months, deleted with your account, and can be deleted earlier by tapping the delete button in Settings (which deletes both Say it recordings and conversations) or by asking us by email. Recordings shared without an account before sharing required one are tied to an anonymous device code and can be deleted from that device in Settings. Also, if you tick “Send recordings for diagnostics” when reporting a problem in a conversation, the recordings of your latest lines in that conversation are kept with the report; they are stored and deleted the same way.
• Browser extension. The browser extension looks words up on your device: the text you select and the pages you read are not sent to us. It reads a page only when you ask it to (the right-click menu, the toolbar button or the keyboard shortcut). Words you save without signing in, and the name and address of the site they came from, stay in your browser until you remove them. If you sign in in the extension, it asks our server for the learning stage of the words it shows (by their word number, not the text around them) and saves or removes the words you choose in your favourites; it keeps its sign-in tokens in your browser until you sign out, and on our server they expire after 90 days without use.
• Support messages, reviews and surveys. Whatever you tell us when you write to support, the rating and words you send from the app's review form, and your answers to our surveys.

We do not collect your contacts, location, photos, health data or advertising identifier, and we do not keep voice recordings unless you turn on “Help improve tone training” or send them with a problem report.

3. Why we use it

• to provide the Service: sign-in, keeping and syncing your progress, building your study rounds — necessary to perform our agreement with you;
• to send the sign-in codes you request;
• to process purchases and meet accounting and tax obligations;
• to answer support requests and read your reviews and survey answers;
• to understand how the app is used and improve it, and to keep the Service secure — our legitimate interest in a working, safe product.
• to run AI conversations and answer your questions to Bao, including the notes Bao keeps — with your permission, which you give before your first conversation on a device and when you turn on the AI helper in Settings;
• to test and improve pronunciation checks and speech recognition, using the voice and conversation recordings you chose to share — with your consent, which you can withdraw in Settings.

We do not sell your personal data and do not use it for advertising.

4. Who processes it for us

We share data only as far as each function needs:

• Hosting providers — the app’s servers and database run on their infrastructure;
• Cloudflare, Inc. — domain names, encrypted database backups, and routing of emails sent to our support address;
• Resend — sending emails: sign-in codes, service emails about your account and, if you opt in, progress summaries, tips and offers;
• A pronunciation-check service — scores a recording when you tap “Detailed check” in Say it. It receives that one short recording and the word you were asked to say, and handles them under its own privacy policy;
• An AI service — checks your writing when you ask for a writing check. It receives the task, your text and earlier scores and feedback, and handles them under its own privacy policy;
• AI services for conversations — at your request, recognize your line, write and voice the character’s reply and check your pronunciation. They receive the recording of your line and the text of the conversation; your account name and email are not sent;
• An AI service for Ask Bao — answers your questions. It receives your question, the task, the earlier messages of the chat, a short summary of your progress and Bao’s notes; your account name and email are not sent;
• Apple and Google — when you choose to sign in with them; Apple also processes App Store purchases;
• Freemius, Inc. — sells subscriptions on the web as our reseller: it receives your email address and your payment and billing details at checkout and processes them under its own privacy policy;
• A messaging service — our internal support chat and team notifications about sign-ups, purchases and reviews.

5. Where your data is stored

Our servers, database and backups are run by the providers listed above. Some of them work from other countries, including the United States. By using the Service you understand that your data may be transferred to and stored in those countries. We transfer only what each function needs.

6. How long we keep it

• account data and learning progress — while you use the Service, until you delete your account;
• checked writing and feedback — until you delete the saved text in My writing or delete your account;
• sign-in codes — until used or expired (a few minutes);
• purchase records — as long as accounting and tax law requires;
• voice and conversation recordings — not kept by default: a recording sent for the detailed check is discarded after scoring, and conversation lines are not kept after the reply (only the conversation’s time, topic and number of lines are stored, to count your lines, until you delete your account). Recordings and transcripts you chose to share are kept for up to 24 months, or until you delete your account, tap the delete button in Settings, or ask us by email;
• Bao’s notes — until you delete them in Settings or delete your account; the kind and time of your requests to Bao — 30 days;
• server logs — only as long as needed for security.

7. Deleting your account

In the app, open Profile → Delete account. This signs you out on every device right away, clears the progress on that device, and deletes your account, progress and sign-in data from our server 14 days later. Signing in again before then keeps the account. You can also ask us by email at [email protected]. We keep only the records the law requires us to keep (such as purchase records). An App Store subscription is managed in your Apple account settings; deleting your Baozi account does not cancel it.

8. Security

Connections are encrypted (TLS), access to servers and the database is restricted, sign-in tokens are stored as hashes, and backups are encrypted. No method of transmission over the internet is completely secure, but we work to protect your data.

9. Your rights

Depending on where you live, you can ask us to access, correct, export or delete your data, to restrict or object to its processing, and to withdraw a consent you gave. Write to [email protected]; we answer within 30 days. You can also complain to the data protection authority in your country.

10. Children

The Service is not directed at children under 13, and we do not knowingly collect their personal data. If you believe a child under 13 has given us personal data, write to us and we will delete it.

11. Changes

We publish any new version on this page with its date. If a change is significant, we will tell you in the app.

Contact

Service

Baozi

Operator

Ivan Guliaev, individual entrepreneur, Bishkek, Kyrgyzstan

Email

[email protected]

Website

baohsk.com