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 PDF here
or choose it from your files
Your files are never transmitted. Nothing is uploaded.
Before you start
- Once the file is in, you'll see how many signatures it carries.
- A drawn or typed signature isn't a digital signature, so there is nothing to verify on it.
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
Add your file
Add the signed PDF you received — a contract, an official certificate, an invoice or a signed form.
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.
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.