Privacy Policy for 无痛英语 Browser Extensions
Last updated: May 15, 2026
无痛英语 browser extensions ("we", "our", or "the extension") mark English vocabulary on webpages and help users save selected words or phrases for learning. This policy covers the existing 生词标记 extension and the Web 间隔复习 extension.
Information We Process
| Data | How it is used |
|---|---|
| Webpage text | The extension reads webpage text locally in your browser to identify English words and phrases that may need marking. Full webpage content and browsing history are not uploaded to our servers. |
| Vocabulary data | Words, phrases, learning status, known status, review status, review timestamps, selected vocabulary level, and optional surrounding sentence context may be stored locally. In variants that support sign-in, selected vocabulary data may sync to our backend. |
| Account data | If a variant provides sign-in and you choose to sign in, your email address and authentication session are processed to provide account and sync features. The Web 间隔复习 v1.0.0 extension does not require sign-in. |
| Local settings | Extension settings such as enable/disable state, selected vocabulary level, imported word list, review cards, review logs, and local progress are stored in browser storage. |
How We Use Information
We use the information above only to provide core product functionality:
- highlight unknown English words and phrases on webpages;
- show definitions and learning priority hints;
- save words or phrases that you choose to mark;
- schedule and record Web review sessions when the extension includes an internal review page;
- sync vocabulary progress across devices and with the companion app in variants that support sign-in;
- load vocabulary levels and phrase dictionaries.
Third-Party Services
The extension uses Supabase as its backend service for vocabulary level data and phrase dictionary data. Some variants may also use Supabase for authentication and vocabulary sync. We do not use advertising SDKs or third-party analytics trackers in the extension.
Data Sharing
We do not sell, rent, or trade your personal information, vocabulary data, webpage content, or browsing history. We do not use your data for advertising.
Webpage Content
The extension requires access to webpages so it can mark vocabulary inside the page you are reading. This analysis happens locally in your browser. The extension may save only the specific words, phrases, review actions, and optional context sentences that you choose to mark while using the product. Full webpages and browsing history are not uploaded.
Data Storage and Deletion
Vocabulary data and settings are stored locally in your browser. If you use a variant with sign-in and choose to sign in, selected vocabulary data may also be stored in our backend so it can sync across devices and with the companion app.
You can clear local extension data from your browser extension settings. You can also contact us to request account or synced data deletion.
Security
We use browser storage and Supabase authentication/backend infrastructure to protect account and vocabulary data. No method of electronic storage or transmission is perfectly secure, but we take reasonable steps to limit the data we process and use it only for product functionality.
Changes
We may update this Privacy Policy from time to time. Updates will be reflected by changing the "Last updated" date above.
Contact
If you have questions or deletion requests, contact us at liuysh20@gmail.com.