Anchor any file's fingerprint into the Bitcoin blockchain. It becomes a permanent, independently verifiable proof that the file existed at this moment — useful for IP, drafts, predictions, research data, anything. No account. Your file is hashed locally and never leaves your browser — only its 32-byte SHA-256 is used.
Drop any file or choose one — it's hashed locally in your browser and never uploaded.
Powered by OpenTimestamps. This is a decentralized proof-of-existence anchored to Bitcoin — not an RFC-3161 or qualified electronic timestamp. Need signatures and an audit trail too? Sign documents with ProofLeaf.