Verify any document, instantly
Confirm whether a PDF was signed through MamaSign and check that it hasn't been tampered with. Cryptographic proof, not guesswork.
Drop your PDF here or click to browse
Your file never leaves your device. Only the SHA-256 fingerprint is sent.
How verification works
Three steps. No account required. Your document never leaves your device.
Upload or enter ID
Drop your PDF into the verifier, or enter the document ID printed on every signed document.
Compute fingerprint
A SHA-256 hash is computed locally in your browser. The file itself is never uploaded anywhere.
Match against records
The fingerprint is compared against our cryptographic records to confirm authenticity.
Built on cryptographic proof
Not heuristics. Not metadata inspection. Byte-level SHA-256 verification that catches any modification, no matter how small.
SHA-256 Hashing
Every signed document gets a unique 256-bit cryptographic fingerprint. Change one byte and the entire hash changes.
Zero-Knowledge
Your document never leaves your browser. Only the computed hash is sent to our servers for matching.
Immutable Records
Once a document is completed, it is cryptographically sealed. The hash is stored permanently and cannot be altered.
Audit Chain
Every signing event is recorded in a hash-linked audit chain. Each entry references the previous, preventing tampering.
Who uses document verification
Anyone who receives a signed document and needs to confirm it's genuine.
HR & Legal Teams
Confirm employment contracts, NDAs, and compliance documents are the exact versions that were signed.
Clients & Partners
Verify proposals, service agreements, or invoices received via email haven't been altered in transit.
Auditors & Regulators
Instantly validate document integrity during audits without requesting re-signatures or original copies.
Common questions
What happens if someone modifies a signed PDF?
Even the smallest change — adding a space, adjusting a margin, re-saving — produces a completely different SHA-256 hash. The verification will immediately show "Not Recognized."
Is my document uploaded to your servers?
No. The SHA-256 fingerprint is computed entirely in your browser using the Web Crypto API. Only the 64-character hash string is sent to our server for comparison. Your file never leaves your device.
What is a Document ID?
Every document signed through MamaSign receives a unique identifier (e.g., MS-A7K9X2B4) printed on the signed PDF. You can use this ID to verify a document without needing to upload it.
Can I verify documents signed by other e-signature platforms?
This tool specifically verifies documents signed through MamaSign. Documents from other platforms will show as "Not Recognized" since their hashes are not in our database.
Ready to sign documents?
Start sending documents for e-signature. Every signed document is automatically verifiable.