Verify a timestamp

Check any OpenTimestamps proof (.ots) against the Bitcoin blockchain — one downloaded from PubPhys or made anywhere else. Add the original file to confirm the proof covers exactly that file.

Check a proof

Proof file (.ots) * Original file (optional, e.g. the .json payload)

The original file is only hashed to compare with the proof; it is not stored.

Checks run against the public OpenTimestamps calendars and the Blockstream block explorer. For a check that trusts no one, use a command-line client with your own Bitcoin node, or the independent verifier at opentimestamps.org.