Privacy Policy — Study Subs

Last updated: 29 July 2026

Study Subs collects nothing. No data is transmitted anywhere — not to me, not to anyone else. There are no accounts, no analytics, no trackers and no third-party services. Everything the extension remembers stays in your browser, on your computer.

What is stored on your device

All of it lives in chrome.storage.local, the browser's own local storage for extensions. It never leaves your machine, and uninstalling the extension deletes all of it.

What	Why it is kept
Your settings: translation language, theme, font size, playback speed, whether the translation row is shown, end-of-sentence pause	So the overlay opens the way you left it
A cache of subtitle text and its word timings for videos you have opened, keyed by YouTube video ID — the 200 most recently used tracks, about 200 KB each	So re-watching needs no network request at all, and the extension keeps working if YouTube rate-limits you
Your study bookmark: the timestamp of the sentence you stopped at, per video ID — the 200 most recent videos, about 50 bytes each	So it can offer to continue where you left off
When YouTube last asked the extension to slow down, and how many times in a row	So it backs off politely, and waits longer each time, instead of retrying into a wall

Be aware of what the second and third rows mean in practice: the list of video IDs you have watched with the extension open is stored locally. It is never sent anywhere, but it is on your disk. You can wipe it at any time — see below.

How to delete the stored data

All of it: remove the extension. Chrome deletes its local storage along with it.
The subtitle cache for the current video: in the overlay, open ⚙ → Advanced → Reload captions.

Network requests

The extension makes requests to exactly one place: youtube.com, the site you already have open. It asks YouTube for the subtitle track of the video you are watching, and for YouTube's own machine translation of that track. Nothing is sent to any other host. There is no server of mine involved — the extension has no backend.

Permissions, and why each one is needed

storage — to keep the settings, the subtitle cache and the study bookmark listed above on your device. Nothing else uses it.
unlimitedStorage — so the subtitle cache can hold 200 tracks; without it Chrome caps an extension's local storage at 10 MB. It grants no access to anything, only room.
Host access to https://www.youtube.com/* — to read the subtitles of the video on the page you are already viewing, and to draw the overlay on that page. The extension has access to no other website.

What the extension never does

It does not collect, transmit, sell or share any personal or usage data.
It does not use analytics, telemetry, crash reporting or advertising.
It does not read pages other than youtube.com.
It does not load or execute any remote code; all of its code ships inside the extension package.
It has no login, no account and no user identifier of any kind.

Not affiliated with YouTube

Study Subs is an independent extension. It is not affiliated with, endorsed by, or sponsored by YouTube or Google LLC. “YouTube” is a trademark of Google LLC.

Contact

Questions about this policy, or about anything the extension does with your data: open an issue at github.com/CinexUA/study-subs/issues.