Captions stay
on your device.

1. Scope

This policy applies to the SpeedSync Chrome extension and the SpeedSync pages published by Rekh. SpeedSync adjusts recorded YouTube video playback toward a listening pace set in words per minute. It has no Rekh account, analytics service, advertising system, telemetry pipeline, crash reporter, or remote configuration service.

2. Data SpeedSync handles

Current video context

The popup checks whether the active tab is a YouTube page and identifies the current video so it can communicate with that tab. The content scripts may read the video's identifier, title, playback state, and caption-track metadata. SpeedSync does not build or retain a browsing history.

Timed captions

SpeedSync reads timed captions already loaded by YouTube's player. It keeps a bounded in-memory cache for the current video so it can estimate source WPM, caption gaps, and the playback multiplier. It may keep up to two caption responses and four caption request URLs in page memory. Navigation clears that cache.

Imported transcripts

If you choose a local VTT, SRT, JSON, or YouTube JSON3 file, SpeedSync reads that file for the current video. Imported transcript text stays in page memory. It is not uploaded by SpeedSync and is cleared on navigation or page reload.

Preferences

SpeedSync stores the enabled state, target WPM, caption-gap speed, speech speed limits, transition setting, and Learning guard preference in Chrome local extension storage.

3. How the data is used

• Estimate the source speaking rate from timed caption words.
• Choose a playback multiplier that moves a passage toward the WPM target.
• Detect caption gaps and apply the separate gap speed.
• Show the current source, WPM estimate, playback state, and transcript details in the popup.
• Keep your playback preferences available between sessions.

Rekh does not use this information for analytics, advertising, profiling, training machine-learning models, or any purpose unrelated to SpeedSync's playback controls.

4. Network requests

SpeedSync can reuse a caption response already loaded by YouTube's player. When needed, it can request the current video's caption URL from YouTube using the browser's existing session and the exact parameters supplied by the player. It may also ask the player to load its selected caption track after you choose Load YouTube captions.

SpeedSync does not send imported transcripts, caption text, request URLs, settings, or playback activity to Rekh or to an analytics provider. It does not use a Rekh backend.

5. Storage and retention

Preferences remain in Chrome local extension storage until you change them, clear extension storage, or uninstall SpeedSync. Caption data, caption request URLs, video context, calculations, and imported transcripts stay in memory for the current page or tab and are cleared when the page lifecycle ends. The extension does not use Chrome Sync.

6. Permissions and site access

• storage keeps the playback preferences described above.
• activeTab lets the popup identify and message the active YouTube tab after you open the extension.
• Access to https://www.youtube.com/* lets the bundled content scripts read timed caption data for the current video and control its playback rate. SpeedSync does not request access to other sites.

All executable code is bundled with the extension. SpeedSync does not download or execute remote code.

7. Sharing and human access

SpeedSync does not transmit user data to Rekh, so no person at Rekh can read a user's captions, imported transcript, video context, or playback settings through the extension. Rekh does not sell this data or transfer it for advertising, credit, lending, or unrelated purposes.

YouTube remains responsible for its own player, caption service, account session, and privacy practices. SpeedSync is an independent Rekh product and is not endorsed by YouTube or Google.

8. Your choices

• Leave SpeedSync off. It starts disabled and does not take ownership of playback until enabled.
• Use YouTube's available timed captions or import a matching timed transcript yourself.
• Turn SpeedSync off to restore the playback rate and pitch setting captured before it took control.
• Clear SpeedSync's extension storage or uninstall it to remove saved preferences from that Chrome profile.

9. Changes and contact

This page will be updated when SpeedSync's data handling changes. Email privacy or security questions to hello@rekh.dev. Do not send a private transcript, private video URL, account information, or screenshots containing them.