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Confirm whether a PDF was signed 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.
Three steps. No account required. Your document never leaves your device.
Drop your PDF into the verifier, or enter the document ID printed on every signed document.
A SHA-256 hash is computed locally in your browser. The file itself is never uploaded anywhere.
The fingerprint is compared against our cryptographic records to confirm authenticity.
Not heuristics. Not metadata inspection. Byte-level SHA-256 verification that catches any modification, no matter how small.
Every signed document gets a unique 256-bit cryptographic fingerprint. Change one byte and the entire hash changes.
Your document never leaves your browser. Only the computed hash is sent to our servers for matching.
Once a document is completed, it is cryptographically sealed. The hash is stored permanently and cannot be altered.
Every signing event is recorded in a hash-linked audit chain. Each entry references the previous, preventing tampering.
Anyone who receives a signed document and needs to confirm it's genuine.
Confirm employment contracts, NDAs, and compliance documents are the exact versions that were signed.
Verify proposals, service agreements, or invoices received via email haven't been altered in transit.
Instantly validate document integrity during audits without requesting re-signatures or original copies.
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."
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.
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.
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.
Start sending documents for e-signature. Every signed document is automatically verifiable.