How do I check that a signed PDF has not been modified?
Drop the document: we read every signature it contains and give a separate verdict for each — content unchanged or not, signature matching the certificate or not.
Check a signature
Check that a signed PDF has not been altered since.
Drop in a signed or sealed document: we read every signature it carries and report on each separately. You will see what is established — the content has not changed, the signature matches the certificate — and what is not. No account, no key, free.
The document is sent so we can read the signatures it carries, then deleted. No account needed.
Common questions
Do I need an account or a key to check?
Neither. Checking is open and free, with no quota: it is something we want to encourage, not bill for.
What does this check not tell me?
It establishes the document's integrity and the signature's validity. It does not say whether the certificate belongs to a recognised authority — that is a matter of trust, not computation.
What happens to my file afterwards?
This tool needs a machine: your file is sent to our servers in Europe, processed, then deleted automatically. We keep no copy and we do not read it.