Privacy policy

Last updated: October 15, 2026

CaptionCat is a browser extension for YouTube captions. It has no accounts, no analytics and no tracking. This page explains what it stores and the one case in which data leaves your device.

What stays in your browser

Everything CaptionCat keeps is stored in your browser's extension storage on your own device. It is not synced to an account and never uploaded by CaptionCat.

• Settings: interface language, caption look, character, its activity level and actions, and the translation and word-saving options.
• Saved words: words you click in captions, with their sentence, the time you saved them and a link to the video.
• Translation cache: up to 500 recent translations, so the same sentence is not requested twice.

Removing the extension deletes all of this. Export your saved words first if you want to keep them.

Hover translation

Hover translation is off until you turn it on. When it is on and you hover over a caption, CaptionCat sends that caption sentence and your chosen target language to Google Translate (translate.googleapis.com) and shows the result. Nothing else is sent: not your saved words, not your browsing history, not the video you are watching. Google's handling of that request is covered by the Google Privacy Policy.

Permissions

• Storage: to keep the settings, saved words and translation cache described above.
• Clipboard write: to copy a review prompt for your saved words, only when you click copy.
• Access to youtube.com: to read the captions YouTube is already showing and draw the caption look and the cat.
• Access to translate.googleapis.com: for hover translation.

CaptionCat does not ask for access to other sites, your history, downloads or tabs.

This website

captioncat.app uses no cookies and no analytics. It is hosted on Cloudflare, which processes standard request data such as IP addresses to deliver and protect the site.

Changes

If this policy changes, the new version will be posted on this page with a new date.