Verify a seal

Everything checks in your browser. Nothing you paste here is sent anywhere.

Salt (shown on the revealed page) The exact revealed text The sealed fingerprint to check against

The fingerprint is SHA-256 of the salt, a newline, then the text.

Checking the Bitcoin anchor

Each seal offers a downloadable .ots proof file. Feed it to any OpenTimestamps client together with the fingerprint and it will confirm the anchor against the Bitcoin blockchain directly. No part of that depends on this site staying online, which is the point.