Privacy Policy

1. Who We Are

This Privacy Policy describes how the Chrome extension Bilibili Download Assistant (“the Extension”, “we”, “us”, or “our”) accesses, uses, stores, and protects information when you install and use the Extension.

Developer / Data Controller contact: jiangwenchao6666@gmail.com

2. Single Purpose

The Extension has a single, narrow purpose: to help users download videos from the Bilibili website (including related video pages and playback resources) for personal offline use.

All data access described in this Policy is limited to what is reasonably necessary to provide that purpose, in accordance with the Chrome Web Store Limited Use and user data disclosure requirements.

3. Scope of This Policy

This Policy applies to:

• The Extension when installed from the Chrome Web Store or sideloaded for development/testing;
• Data accessed or processed by the Extension on your device;
• Requests the Extension makes to Bilibili-related domains needed for video download functionality.

This Policy does not govern Bilibili’s own website, apps, or services. Bilibili’s handling of your account and content is subject to Bilibili’s own terms and privacy policy.

4. Information We Access or Process

The Extension does not require you to create a separate account with us. Depending on how you use the Extension, it may access or process the following categories of data:

4.1 Authentication / account-related data

• Bilibili login cookie (SESSDATA): If you are logged into Bilibili in Chrome, the Extension may read the SESSDATA cookie solely to determine login status and to request video playback/download information available to your account (for example, higher-quality streams where eligible).

4.2 Website content and video metadata

• Current page URL (to verify you are on a supported Bilibili video or bangumi page);
• Video title, duration, size/quality-related metadata;
• Video identifiers and playback parameters needed to obtain downloadable media URLs;
• Temporary download progress status displayed in the Extension popup.

4.3 Browser / technical data

• Active tab information required to communicate with the current Bilibili page;
• Local Extension state stored via Chrome storage APIs;
• Standard browser/network technical information inevitably involved in requests to Bilibili (for example, request headers required by the browser to fetch video resources).

4.4 Data we do not intentionally collect

We do not intentionally collect or process:

• Payment card numbers or financial account credentials;
• Government ID numbers;
• Precise geolocation;
• Health or biometric data;
• Contacts, SMS, call logs, or personal address books;
• Authentication credentials for services other than what is necessary to interact with Bilibili for downloads;
• Browsing history unrelated to the Extension’s download function.

5. How We Use Information

We use the information described above only to:

• Detect whether the active tab is a supported Bilibili video page;
• Retrieve video metadata and available stream information;
• Enable downloading of the selected video to your local device;
• Show download status and basic video information in the Extension UI;
• Maintain temporary local state needed for the Extension to function reliably.

We do not use Extension user data to:

• Sell, rent, or trade personal data;
• Serve third-party advertisements;
• Build advertising or remarketing profiles;
• Determine creditworthiness or for lending purposes;
• Conduct unrelated product research, analytics, or profiling beyond the Extension’s single purpose.

6. Data Storage, Retention, and Security

6.1 Local storage

Certain temporary data (such as login-session-related state derived from SESSDATA) may be stored locally using chrome.storage.local on your device. This storage is used to support download functionality and login-status checks.

6.2 Retention

Locally stored Extension data is retained only as long as needed for the Extension to operate, or until you clear Extension/site data, remove the Extension, or otherwise delete browser data associated with the Extension.

6.3 Security

We take reasonable technical and organizational measures appropriate to a browser extension, including limiting permissions to those needed for the stated purpose and processing data primarily on your device. No method of electronic storage or transmission is 100% secure. You are responsible for keeping your Chrome profile and Bilibili account secure.

7. Data Sharing and Third Parties

We do not sell user data. We do not share Extension user data with data brokers, advertising networks, or analytics companies for secondary commercial purposes.

To provide the download function, the Extension communicates with Bilibili-related hosts, which may include:

• *.bilibili.com — video pages and site interaction;
• api.bilibili.com — video metadata / play URL APIs;
• *.bilivideo.com — video media file retrieval.

Those communications are necessary to fetch video information and media files from Bilibili. Bilibili may process related network requests under its own policies. The Extension does not upload your data to a separate developer-operated backend for advertising, resale, or unrelated analytics.

8. Permissions and Why They Are Needed

The Extension requests the minimum permissions reasonably required for its single purpose. The following table summarizes the permissions and host access used by the Extension:

9. Chrome Web Store Limited Use Commitments

Consistent with Google’s Chrome Web Store User Data Policy, we certify that:

• The use of data obtained via the Extension is limited to providing or improving the Extension’s single purpose of downloading Bilibili videos.
• We do not transfer or sell user data to third parties, except as necessary to provide or improve the Extension’s functionality (for example, communicating with Bilibili services to fetch video resources), for security/legal compliance, or with explicit user consent.
• We do not use or transfer user data for serving advertisements, including retargeting, personalized, or interest-based advertising.
• We do not use user data to determine creditworthiness or for lending purposes.
• We provide users with this Privacy Policy disclosing our data handling practices.

10. Your Choices and Controls

You can control the Extension’s access to your data by:

• Using the Extension only on pages/videos you choose;
• Logging out of Bilibili if you do not want login-related cookies to be available;
• Clearing site data / Extension data in Chrome settings;
• Disabling or uninstalling the Extension at any time in chrome://extensions;
• Managing Chrome cookie and site permission settings.

Uninstalling the Extension stops future data access by the Extension. Data already downloaded to your device remains under your local control.

11. International Users

The Extension operates in your browser. Depending on your location and network routing, requests to Bilibili services may be processed in jurisdictions where Bilibili or its infrastructure providers operate. If you use the Extension, you understand that such functional network requests are necessary to retrieve video information and files.

12. Children’s Privacy

The Extension is not directed to children under 13 (or the minimum age required in your jurisdiction). We do not knowingly collect personal information from children. If you believe a child has provided personal information through the Extension, contact us and we will take reasonable steps to delete related locally controlled Extension data where applicable and advise on account/browser steps.

13. Legal Bases (Where Applicable)

If you are located in a region that requires a legal basis for processing (such as the EEA/UK), we rely on one or more of the following, as applicable:

• Contract / service provision: processing needed to provide the download features you request;
• Legitimate interests: operating, securing, and maintaining the Extension’s core functionality;
• Consent: where required by law for specific optional processing (if introduced in the future and disclosed).

14. Changes to This Privacy Policy

We may update this Privacy Policy from time to time to reflect changes in the Extension, legal requirements, or Chrome Web Store policies. When we make material changes to our data handling practices, we will update the “Last updated” date at the top of this page and take reasonable steps to notify users (for example, via the Chrome Web Store listing and/or Extension release notes), consistent with applicable disclosure requirements.

Continued use of the Extension after an updated Policy becomes effective constitutes acknowledgment of the updated Policy, except where additional consent is required by law.

15. Contact Us

If you have questions, requests, or concerns about this Privacy Policy or our data practices, please contact:

Email: jiangwenchao6666@gmail.com
Extension name: Bilibili Download Assistant

Please replace the placeholder email address above with your real support contact before submitting this page to the Chrome Web Store.