PDF Digital Signature Integrity Checker

Inspect whether a supported PDF signature cryptographically matches its signed revision. This does not establish signer trust or eIDAS qualified status.

Local: yes. Your input stays on your device and is not sent to an external service for this tool.

Choose a signed PDF Choose a file or drop it here

Up to 24 MB. Original file stays on your device.

ByteRange extraction and detached CMS verification use bundled PKIjs in this browser. No external certificate or timestamp lookups.

What is validated?

For supported detached CMS PDF signatures, the original signed bytes and CMS signer cryptographic signature are checked. Bytes appended after the signed revision are reported separately. A PDF can contain more than one signature or unsigned incremental updates.

What is not validated?

Signer identity, certificate chain, revocation, trusted timestamp, legal validity and eIDAS qualified status are NOT verified. A cryptographic match never proves the signer is trustworthy. Some PDF structures may be unsupported.

Are my files uploaded?

No. PDF signature processing runs with JavaScript and WebAssembly running in your browser tab. Your files are read from your device and the results are created on your device; nothing is sent to gratistools.be or anyone else, which is also why there are no queues, daily limits or watermarks. See the privacy page.

Frequently asked questions

Is this tool free?

Yes. The core tool is free to use in your browser.