Privacy Policy for Web Video Sync

Last updated: August 19, 2026

Web Video Sync is a browser extension and synchronization service that allows two consenting participants to synchronize playback of videos they already have open on supported websites.

Web Video Sync synchronizes playback controls and timing information only. It does not download, proxy, decrypt, retransmit, or redistribute video or audio streams.

1. Information We Process

Web Video Sync processes only the information necessary to provide video playback synchronization.

This may include:

• Video identification information needed to determine whether participants are watching the same video.
• Playback state, including play or pause state, current playback position, playback rate, and synchronization timing information.
• Room and participant state required to create, join, and maintain synchronization sessions.
• Authentication and session tokens used to communicate securely with the Web Video Sync service.
• The configured Web Video Sync API server origin.
• Temporary queued synchronization messages used to recover from page refreshes, extension reloads, or temporary network interruptions.

2. Information We Do Not Collect

Web Video Sync does not collect or store:

• Video content.
• Audio content.
• Screen recordings or screenshots.
• Browsing history.
• Cookies from websites you visit.
• Passwords.
• Payment information.
• Page text unrelated to video synchronization.
• Form input unrelated to Web Video Sync.
• Messages, emails, or other unrelated browser data.

Web Video Sync does not capture, download, proxy, decrypt, or redistribute the video being watched.

Each participant accesses and watches the video directly from the original website.

3. Browser Storage

The extension uses the browser's extension storage functionality to keep information necessary for operation across browser restarts, page refreshes, and extension reloads.

Stored information may include:

• Authentication or session tokens.
• Selected API server configuration.
• Active room state.
• Participant role.
• Synchronization state.
• Temporary queued playback progress or control messages.

This storage is used only to provide and maintain Web Video Sync functionality.

Web Video Sync does not use browser storage to build browsing profiles or track users across unrelated websites.

4. Website Access and Host Permissions

Web Video Sync requires access to supported video websites in order to detect the active HTML5 video player and synchronize playback.

Currently supported or tested websites include:

• YouTube
• Bilibili
• yfsp.tv (爱壹帆国际版)

The extension may also provide limited support for other websites that use standard HTML5 video players through a generic fallback mechanism.

On supported pages, Web Video Sync accesses only information required to identify and control the relevant video player, including playback state such as play, pause, playback position, and playback rate.

Host permissions may also be used to communicate with the configured Web Video Sync API server for authentication, room management, and synchronization messaging.

Web Video Sync does not use host permissions to collect unrelated page content or general browsing activity.

5. Synchronization Between Participants

When two users intentionally join the same synchronization room, playback information necessary for synchronization is exchanged through the Web Video Sync service.

This may include:

• Video identity.
• Current playback position.
• Play or pause state.
• Playback rate.
• Synchronization timing information.
• Room-related synchronization messages.

Video and audio content are never transmitted through Web Video Sync.

Participants must intentionally create or join the same synchronization room before synchronization occurs.

6. Guest Rooms and Invitations

Web Video Sync may support temporary guest rooms that do not require an account.

Guest-room invitations are designed to be short-lived and may be restricted to a single use.

Room credentials and related authorization information are used only to establish and maintain the requested synchronization session.

7. Server Processing

Information required for synchronization may be transmitted to the configured Web Video Sync server.

The server processes synchronization messages in order to:

• Authenticate participants.
• Create and join rooms.
• Maintain room membership.
• Relay playback synchronization state.
• Handle connection recovery and temporary disconnects.
• Protect rooms from unauthorized access.

The service does not use synchronization data for advertising or behavioral profiling.

8. Data Retention

Web Video Sync is designed to retain synchronization information only for as long as necessary to provide the service.

Temporary room state, invitations, synchronization messages, and session information may expire automatically or be removed when they are no longer needed.

Some information may remain temporarily in local extension storage to support reconnection or recovery after a browser refresh or temporary connection failure.

9. Data Sharing

Web Video Sync does not sell personal information or synchronization data.

Information is shared only as necessary to provide the synchronization functionality requested by participating users.

Playback synchronization information may be relayed between participants who intentionally join the same room.

We do not share synchronization data with advertisers or data brokers.

10. Tracking and Advertising

Web Video Sync does not use synchronization information for:

• Advertising.
• Behavioral advertising.
• Cross-site tracking.
• User profiling.
• Selling user data.

11. Security

Web Video Sync is designed to limit access to synchronization rooms to authorized participants.

Production deployments are intended to use encrypted HTTPS and secure WebSocket connections (WSS).

Authentication credentials, room authorization credentials, and other security-sensitive information are not intentionally exposed to supported website pages.

No method of electronic transmission or storage can be guaranteed to be completely secure, but reasonable measures are used to protect information processed by the service.

12. Third-Party Websites

Web Video Sync operates alongside third-party video websites such as YouTube, Bilibili, and yfsp.tv.

Those websites operate independently from Web Video Sync and have their own privacy policies, terms, cookies, authentication systems, and data practices.

Web Video Sync does not control the privacy practices of those third-party websites.

13. Children's Privacy

Web Video Sync is not designed to knowingly collect personal information from children.

Users should use Web Video Sync only where permitted by applicable laws and the terms of the websites on which they use the extension.

14. Changes to This Privacy Policy

This Privacy Policy may be updated when Web Video Sync functionality, data handling practices, or legal requirements change.

The "Last updated" date at the top of this page will be updated when material changes are made.