Document integrity
We check that the signed content hasn’t changed since signing and that the signature matches the certificate.
Verify PDF signature
Open a signed PDF and instantly see who signed it, when, with which certificate, and whether the document has changed since it was signed. Verification runs in your browser.
- End-to-end encrypted
only you can see what’s inside - Deleted after 1 hour
from your last edit - Free, no cookies
no sign-up
Drag and drop a PDF here
or
Select signed PDFUp to 100 MB · opens instantly
How it works
- 1
Open your PDF
Drag the signed document into the window.
- 2
View the signatures
An overview of the signatures opens: who signed, when, with which certificate, and whether the signature is intact.
- 3
Check the details
For each signature, you’ll find the certificate issuer, timestamp, reason and location of signing, and technical details.
What it can do
Signing time
We distinguish between a time confirmed by a timestamp and one taken from the signer’s computer clock.
Multiple signatures and later changes
For a document signed by several people in turn, we show the order of signatures and flag changes made after signing.
Document properties
Author, application, PDF version, fonts, encryption and attachments, such as an embedded e-invoice.
Frequently asked questions
What exactly is verified?
Integrity (that the signed bytes of the document haven’t changed since signing) and the cryptographic validity of the signature against the certificate, including the timestamp. We support PAdES and PKCS#7 signatures as well as document timestamps.
Do you also check whether the certificate is trusted?
We don’t check here whether the certificate issuer is among the trusted (qualified) authorities. We do show the issuer, though, and whether the certificate is marked as qualified. Full validation, including lists of trusted authorities, is available in Adobe Acrobat Reader.
What does “the document was changed later” mean?
After signing, someone appended further changes to the file – for example, filled in a form or added a comment. The signed version is intact, but the signature doesn’t cover the later changes.
Can I add my own signature to a signed document?
Yes. As long as you don’t edit the document, earlier signatures stay valid and your signature is added – see “Digitally sign PDF”.
Who can see my document?
Only you and anyone you send the link to. The document is edited in your browser and only ever reaches our server encrypted. The copy deletes itself one hour after your last edit. Learn more in our privacy policy.