How to Verify a PDF Digital Signature Online — Free & No Upload Required
Check that a digitally signed PDF is authentic and hasn't been tampered with since it was signed — entirely in your browser.
A digital signature on a PDF cryptographically ties the document's exact byte content to a signer's certificate. If even one character changes after signing, the signature becomes invalid — which is exactly what makes verification useful for confirming a document is genuine and unmodified.
Step-by-Step: Verify a Signature Using iCreatePDF
- Open iCreatePDF Verify Signature.
- Upload the signed PDF you want to check.
- iCreatePDF validates the cryptographic signature and byte-range integrity.
- Review the signer identity details and validity status shown in the result.
Privacy Guarantee: Signature validation is computed entirely in your browser. Sensitive signed documents like contracts or legal filings are never uploaded to a server.
6 Reasons to Verify a Signed PDF
Contract Verification
Confirm a signed contract's digital signature is valid and hasn't been altered since signing.
Vendor Document Checks
Verify a supplier's signed compliance certificate before accepting it.
Legal Filings
Check the integrity of a digitally signed legal document before relying on it.
Government Documents
Validate the signature on an officially issued digital certificate or permit.
Software License Files
Confirm a digitally signed license or authorization document is authentic.
Auditing Received Files
Check whether a PDF you received has been modified after it was originally signed.
Digital Signatures vs. SHA-256 Fingerprints
A digital signature (checked here) uses a signer's certificate and is the standard for formally signed documents like contracts. A simpler alternative — a SHA-256 fingerprint — lets you certify and later verify that a document hasn't changed, without requiring a formal certificate. If you want to add tamper-evidence to a PDF you're creating rather than verify one you received, see Certify PDF.
iCreatePDF vs Other Signature Verification Tools
| Feature | iCreatePDF | Typical Online Tools |
|---|---|---|
| File uploads to server | Never | Always |
| Account required | No | Often yes |
| Suitable for confidential contracts | Yes — nothing leaves your device | Risky — signed documents get uploaded |
| Cost | Free | Freemium / paywalled |
Frequently Asked Questions
What does it mean if a signature shows as invalid?
It usually means the document was modified after signing, or the signature data itself is corrupted. Either way, treat the document as unverified until confirmed with the original signer.
Can I verify multiple signatures on one document?
Yes — PDFs can carry multiple signatures (for example, from different approval stages), and each is validated independently.
Does verification confirm the signer's real-world identity?
Verification confirms the certificate used matches the signature and the document is unaltered. Trusting the signer's identity also depends on whether that certificate was issued by a trusted authority.
Is this the same as checking if a PDF is encrypted?
No — encryption and digital signatures are separate features. Verification here checks signature validity, not password protection.
Verify your PDF signature now — free & private
No sign-up. No uploads. Your files stay on your device.