Verify a digital signature with confidence
A digital signature verifier does more than say "valid" or "invalid": it shows you the evidence. It confirms that the document hasn't changed since it was signed, proves the signature genuinely came from the holder of a particular certificate, and lets you inspect exactly who that signer is. Whether you're checking a contract, an offer letter, a government certificate, or an Aadhaar PDF, verification turns "I hope this is real" into "I can see that it is."
How verification works
When you drop a signed PDF above, the verifier locates each signature's ByteRange and
its embedded PKCS#7 / CMS signature, recomputes the hash of the signed bytes, and compares it with
the message digest recorded in the signature. It then verifies the signature itself against the
signer's public key using your browser's built-in WebCrypto engine. Finally it parses the signer's
X.509 certificate and attempts to build the trust chain. To learn the theory behind each step,
see what a digital signature is.
Inspect the signer's certificate
Verification is only meaningful if you can see who signed. The verifier displays the certificate's common name and organization, the issuer, the serial number, the validity period, and the signature and hash algorithms (for example RSA with SHA-256). For government documents the signing authority is immediately clear, for instance UIDAI on an Aadhaar PDF.
Trust chain and revocation
A certificate is trustworthy only if it chains up to an authority you trust. The verifier builds that chain and reports it honestly as Trusted (chains to a known root), Untrusted (chain complete but the root isn't one we vouch for), or Unknown (chain incomplete). It also surfaces the certificate's CRL and OCSP revocation endpoints, so you can see where revocation status would be checked. We never claim trust we can't prove; you always see the full picture.
Designed for sensitive documents
Verifying a signature often means handling confidential material. That's why this verifier never uploads your file: everything runs locally in your browser, and nothing is stored or logged. It's safe for Aadhaar, financial statements, legal agreements, and anything else you'd rather not send to a stranger's server.
Verify, then sign
If you also need to apply a signature, you can digitally sign a PDF in your browser using your own certificate or a self-signed one, then verify the result here to see the whole cycle. For step-by-step help reading results, see how to check a PDF signature, or why a signature might show as not valid.