Verify the signatures in a PDF
For every digital signature in a document: who signed it and when, whether it is valid, and whether anything changed after it was signed.
What PDF signature verification tells you.
Valid or not
The document digest is checked and the signature verified against the certificate embedded with it.
Changed after signing?
See whether anything was added after a signature, or the document was altered or rewritten.
Signer, time and reason
Read who signed, when and why, for every signature in the file.
Certification level
Tell an approval signature from a certifying one, and its permitted-changes level.
Plain-language result
Each signature comes with a one-line summary ready for a list in your UI.
Across platforms
A document signed with PDF-SDK on one platform verifies on another.
From your code.
Lists every signature with its signer, time, verdict and summary.
See the API referenceimport { verifySignatures } from '@pdfsdk/editor';
for (const s of await verifySignatures(editor, bytes)) {
console.log(s.signer, s.time, s.valid, s.summary);
}
// "Valid — signed and not modified"
// "Valid — but the document was changed after this signature"
// "Invalid — the document was altered after signing"Verify signatures questions.
Verify its signatures: each result says whether the signature is valid and whether the document was changed, altered or rewritten after it.
The signer, signing time and reason, whether it is valid, whether it covers the whole file, its certification level and a one-line summary.
Try it in your app.
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Talk to us
Questions about licensing, several apps, volume, or OEM and site terms — we will work out what fits.