Verify Signature
Enterprise-grade document protection and authentication tools.
Securing Document...
Applying cryptographic layers and processing assets
What is Verify PDF Signature?
Verify PDF Signature inspects the cryptographic digital signatures embedded in a PDF and tells you whether each one is trustworthy. When someone signs a PDF digitally, their certificate and a tamper-evident hash of the document are sealed inside the file — this tool checks the certificate chain, confirms the signer's identity, and detects whether even a single byte changed after signing. It answers the question paper can't: is this signed contract, certificate, or approval letter genuinely from who it claims, and has it been altered since?
How to use
- Upload the digitally signed PDF you want to check.
- The tool locates every signature field in the document and reads the embedded certificates.
- Each signature gets a verdict — valid, invalid, or unknown — with the signer's name, certificate issuer, and signing timestamp shown alongside.
- Review the detailed report: it flags exactly which signature failed and why, such as post-signing edits or an expired certificate.
Common use cases
- An HR manager verifies a digitally signed employment contract to confirm the candidate's signature is genuine before onboarding.
- A freelancer checks a client-signed statement of work to make sure the terms weren't altered after the client signed.
- A university admissions office validates digitally signed degree certificates submitted by applicants.
- A procurement officer confirms that a supplier's signed quotation still matches the version that was originally approved.
FAQs
What does it mean if a signature shows as invalid?
Invalid means the cryptographic check failed — most commonly because the document was modified after signing (even a one-character edit breaks it), or the signer's certificate has expired or been revoked. The report pinpoints which of these caused the failure.
Can it verify a scanned handwritten signature?
No. A scanned squiggle is just an image on the page with no cryptographic data behind it. This tool only verifies true digital signatures — the kind created with a certificate that mathematically binds the signer's identity to the document's exact contents.
What's the difference between an electronic and a digital signature?
An electronic signature is any mark of agreement — a typed name, a drawn squiggle. A digital signature is a specific cryptographic mechanism using certificates and hashing. Only digital signatures can be mathematically verified, which is what this tool does.
Do I need the signer's certificate installed on my device?
No. The certificate travels inside the PDF itself, and the tool reads it from there during verification. Everything runs in your browser with no signup, and your uploaded document is deleted from the server automatically once the check completes.