Privacy

Short version: your thumbnail never leaves your device.

• When you choose, drop or paste an image, your browser opens it locally. All checks and previews are computed by JavaScript on this page. The image is not uploaded, stored or sent anywhere.
• The page's Content Security Policy blocks the page from making network requests from its scripts (connect-src 'none'), so it can't send your image anywhere even by mistake. You can confirm this in your browser's developer tools (Network tab).
• No accounts, no cookies, no analytics, no ads, no third-party scripts or fonts.
• The title, channel name and duration you type into the feed preview stay on the page. They are gone when you close or reload it.
• The hosting provider may keep standard server logs (such as IP address and time of request) when the page itself loads. That's normal for any website and doesn't include your image.
• Links to other sites (for example YouTube Help or our template kit) follow those sites' own privacy policies.

Ads

There are no ads right now. We may later add one small display banner in the page footer from a third-party ad network, to keep ThumbCheck free. If we do, this page will be updated first: it will name the network, say that the network may set cookies or collect device data under its own privacy policy, and explain what changes in the Content Security Policy above. The ad would never receive your thumbnail or the text you type, and we don't sell personal data.

If this ever changes (for example, if ads are added), this page will be updated first and will say exactly what changed.

Last updated: October 22, 2026.