About LegalStamp

We help creators, businesses, and legal professionals prove the priority of their documents in seconds using the Bitcoin blockchain.

Our mission

LegalStamp makes legal timestamping simple, fast, and transparent. We use the OpenTimestamps protocol to anchor a cryptographic fingerprint of your files in the Bitcoin blockchain, without ever storing the document itself.

Our ambition is to democratize reliable proof of existence, complementary to traditional approaches (INPI, Soleau envelope), with a smooth user experience and a strong commitment to confidentiality.

What sets us apart

  • Total privacy: the file stays on your device.
  • Verifiable and independent proof on Bitcoin.
  • Clear pricing, freemium and no commitment.

Our values

Transparency

We use the open source OpenTimestamps protocol. Every proof is independently verifiable, without depending on LegalStamp.

Privacy

Your files never leave your browser. We only collect the cryptographic fingerprint, making any content reconstruction impossible.

Accessibility

A free plan for everyone, clear pricing, and an interface designed to be usable without technical expertise.

Our technology

LegalStamp relies on the OpenTimestamps protocol and the Bitcoin blockchain. Your file's SHA-256 hash is computed locally, then anchored via a Merkle tree in a Bitcoin transaction. This architecture guarantees an immutable proof, verifiable by anyone, independent of any trusted third party.

Key figures

Average creation time
< 30 seconds

Legal credibility

In March 2025, the Marseille Judicial Court recognized the evidentiary value of a Bitcoin blockchain timestamp to establish the priority of a creation. This event confirms the relevance of proof based on OpenTimestamps.

Contact us

A question or specific need? Write to us at [email protected].