Validate PDF Signature
Validate PDF signatures and see at once whether the file was changed after it was signed. The check runs offline in your browser.
How to validate PDF signature
Drop a signed PDF into the box.
Read the result for each signature in the file.
What the check covers
For every digital signature, the tool confirms the signature is mathematically valid and the signed bytes are unchanged. It also tells you whether the signature covers the whole file, since content added after signing sits outside it.
You also see the signer name, the certificate issuer, its validity dates and the signing time.
Offline, so trust is up to you
The check runs without contacting any server. That means it does not confirm revocation or whether a certificate authority vouches for the signer. A valid result proves the file matches what was signed, not who the signer really is. To sign a file yourself, use Digital Signature PDF. The guide to digitally signing a PDF explains the difference.
Guides
Frequently asked questions
How do I validate a PDF signature?
Drop the signed PDF here. Each signature is checked and the result is shown with the signer details.
Can it tell if a signed PDF was changed?
Yes. It checks whether the signed bytes are unchanged and whether the signature covers the whole file.
Does it check certificate revocation?
No. The check is offline, so it does not confirm revocation or trust in a certificate authority.
What details does it show?
Signer name, certificate issuer, validity dates and signing time for each signature.
Does it work on a visual signature?
No. A drawn signature from Sign PDF is part of the page, not a digital signature, so there is nothing to validate.