Verify PDF signature
Check a PDF's digital signatures: signer, certificate, date and document integrity.
Frequently asked questions
What exactly does it check?
For each signature it hashes the signed parts of the PDF and compares the result with the hash stored in the signature, then verifies the CMS signature with the certificate's public key. It also shows whether the document changed after signing, who signed, the issuer and the certificate validity.
Does it replace Adobe Acrobat or official validators?
Not entirely. It checks integrity and signature details, but without a server it can't query certificate revocation (OCSP/CRL) or official trust lists. For full legal validation use Acrobat or an official validator.
What does "modified after signing" mean?
The PDF has changes saved after the signature (incremental updates). If those changes are only new signatures it says so separately; otherwise you should review the original signed version.
Is the PDF uploaded anywhere?
No. The file is analyzed entirely in your browser.
Is Verify PDF signature free to use on Toolkoa?
Yes, the Verify PDF signature tool is 100% free, unlimited and requires no sign up or installation.
Are my files sent to any server when using Verify PDF signature?
No. Every operation on Toolkoa is processed privately and locally, directly in your own browser.
Do I need to install anything to use Verify PDF signature?
Nothing to install. Verify PDF signature runs in any modern desktop or mobile browser, and once the page has loaded you can keep using it without relying on the connection.