ExtLab Dual Subtitles privacy policy

ExtLab Dual Subtitles does not collect the URLs you visit, your name or your email address. It reads subtitles on the sites listed below. Subtitle text leaves your browser only when you use AI features, as the AI section explains. Your data stays in your browser unless a section below says otherwise.

Permissions

• storage: Saves your settings and your saved words in your browser.
• alarms: Runs one daily check of your license, and syncs saved words with Pro.

Sites

• https://www.youtube.com/*: Reads the subtitles of the video you watch, and shows the two lines over the player.
• https://www.netflix.com/*: Reads the subtitle line the player shows, and shows the two lines over the player (Pro).

AI features

AI translation sends the subtitle lines of the video you watch. A word explanation sends the word or phrase you picked and its subtitle line. Each request also holds the two languages, the video id, a random install id and, with Pro, your license key. It goes to https://api.extlab.app, and we send the text to Anthropic, which runs the Claude model. Anthropic acts as our processor under its commercial terms. AI translation is on by default. With Basic translation, chosen in the menu, none of this leaves your browser: subtitles come from the site, and Chrome's on-device translator runs on your computer.

We keep answers in a shared cache under a hash of the video id, the languages and the subtitle text, so that a popular video is translated once. The cache holds the answer and not the original text, and each entry is deleted after 90 days. We count tokens and spend per install id and per key hash to enforce limits, and delete those counters 62 days after their last use.

Saved words

Saved words, with their sentences and video links, stay in your browser. With Pro they sync through our servers, as described under Synced data.

Anonymous usage statistics

The extension sends install, update, uninstall and daily activity events, plus error reports with URLs and file paths removed. Each event holds a random install id, the extension version, your browser language and whether Pro is active. We delete events after 90 days. Turn this off at any time in the extension's options page.

License keys

Gumroad handles payment and is the merchant of record. ExtLab never sees your card. When you activate a key, the extension sends it to https://api.extlab.app, and we check it with Gumroad. We store a hash of the key, its plan and expiry, and the random install ids using it.

Synced data

If a Pro feature syncs data between your devices, that data is stored on our servers, tied to the hash of your license key. It is stored as you created it and is not end-to-end encrypted. Nothing is synced without an active license.

Sharing

We do not sell data. Gumroad handles payments and license checks. Cloudflare runs our API and Turso hosts our database, and both process data only to provide those services. Anthropic runs the AI features. See the ExtLab privacy policy for details and your rights.

Contact

Questions or a deletion request: [email protected].