Last updated: August 30, 2026 ｜ Effective date: August 30, 2026

1. Scope

This policy applies to the Edu Practice Tools website (www.baigongchang.com, "we", "us", "our") and all of its online tools and the Offline Edition product.

2. Information We Collect

All processing happens locally in your browser — your content never leaves your device by default. We collect only the minimal anonymous data needed to improve the service:

• Anonymous usage statistics: page views and button clicks (visit time, page, referrer and browser info, used to measure traffic and feature usage);
• Language preference: your chosen interface language (Chinese/English) is stored in your browser's localStorage and used only on your device;
• Third-party analytics: may include services such as Baidu Analytics (fully silent with no requests until a site ID is configured). None of it includes your input content;
• AI feature input: only when you actively use an AI generation feature (e.g., AI math word problems, AI text polishing, AI vocabulary for character sheets), the parameters and text you submit for that request (such as grade range, source text, characters) are sent to a third-party model provider to generate content and return it to your browser. No such data is sent unless you use an AI feature.

3. Information We Do NOT Collect

• The text, pinyin, math problems and images you enter — except for the AI generation features described above, all computation runs locally in your browser and even works offline;
• Your name, email, phone number or other personal identifiers (except when you email us directly);
• No advertising-tracking cookies and no personalized ads.

4. AI Generation Features and Third-Party Model Providers

• How it works: AI generation is a paid subscription add-on. The site proxies your request through its server to a third-party model provider (such as DeepSeek, OpenAI, etc.) using their public API. Only the parameters needed for that request are forwarded — never your account information;
• Data scope: The content sent to the model provider is strictly limited to the parameters and text of that single request. The model provider processes it under its own privacy policy. We do not store, sell, or use it for any other purpose;
• Model training: We arrange with model providers that your input is not used for model training (subject to each provider's own privacy policy);
• Generated content: AI-generated content may contain errors and is provided for teaching reference only — please verify it before use;
• How to opt out: Simply do not use the AI generation features (they are unavailable in the free tier) — then no data is ever sent to any model provider.

5. How We Use and Store Information

• Statistics are used only to understand traffic and usage, and to improve the products;
• Statistics logs are stored on the hosting server (auto-rotated beyond 5MB), accessible only by the site owner, and are never sold or shared with third parties.

6. Children's Privacy

Our tools are designed for use by parents and teachers and do not knowingly collect personal information from children under 14. If you believe a child has provided us with information, please contact us and we will delete it.

7. Information Security

The site is served over HTTPS. Our statistics endpoint applies rate limiting and content whitelists. Because we do not collect your input or identity data, even a data breach would not expose your personal information.

8. Your Rights

You may clear the localStorage data from your browser settings at any time. To inquire about or request deletion of records related to you, please contact us below.

9. Changes to This Policy

We may update this policy as the service evolves. Updates will be posted on this page with a revised "Last updated" date. Material changes will be highlighted.

10. Contact Us

For any questions about this policy, please email support@baigongchang.com.