Check whether a signed PDF is valid, who signed it and if it was changed.
Checks a PDF's digital signatures: whether the document changed after signing, who signed, when, and which authority issued the certificate.
How to use it
Choose the signed PDFs.
Tap «Verify signature».
Read each signature's result and download the report.
When it helps
Check a contract or certificate received by email.
Limitations
We check integrity and certificate details; trust in the issuing authority (official lists) is confirmed in Adobe Reader or official validation services.
Frequently asked questions
What does «changed after this signature» mean?
The file was updated later, for example with another signature or annotations. It isn't necessarily fraud, but worth checking.
Privacy
This processing happens on your device. The file is not uploaded to our servers and is gone from memory when you close the page.