Verify PDF signature
Check whether a signed PDF has changed since it was signed — nothing uploaded.
- Zero-transmission processing
- No watermark
- Limited daily trial
- Unlimited on Pro
Drop your PDFs here
or pick them from your device
Your files are never transmitted. Nothing is uploaded.
Good to know
- Accepts
- Files at once
- One at a time
- Transmission
- None — nothing is uploaded.
Chain it
Run this tool and the next one back to back — nothing to download in between.
How to do it
- 1
Add your file
Add the signed PDF you received — a contract, an official certificate, an invoice or a signed form.
- 2
Set it up the way you want
Nothing to configure. The tool checks whether the document changed after signing and whether each signature matches its certificate.
- 3
Download the result
Read the report: which signatures are intact, which parts of the file fall outside the signed range, and what could not be checked.
Questions about Verify PDF signature
- How can I tell if a signed PDF has been altered?
- Add it here. Every digital signature covers a byte range of the file; if anything inside that range changed, or content was appended afterwards, the report says so plainly.
- Does this prove the signer is who they claim to be?
- No, and the report is explicit about it. Confirming identity needs a trusted root certificate list, which this tool does not carry; it checks integrity and that each signature matches its own certificate.
- Is the signed document uploaded to check it?
- No. The verification runs without transmitting the PDF, which matters for contracts and certificates that should not pass through anyone else's servers.