Verify a signed document

Check that a Closign document is genuine and hasn't changed since signing.

The document ID and fingerprint are in the completion email. A PDF you drop is checked and discarded, never stored.

How verification works

When every party has signed, Closign seals the final PDF, adds the certificate of completion as its last page and records the file's SHA-256 fingerprint. If even one byte of the file changes, its fingerprint changes too.

Drop the signed PDF and we compare its fingerprint with every sealed document. Use the copy you received from Closign: printing or re-saving it makes a different file.
Or enter the document ID and fingerprint from the completion email (at least the first 16 characters) to see the sealed record.
We only show a document to someone who already has it. Signer emails are partly hidden.