Validate Signature
Verify existing signatures and certificates
Drop your PDF here or click to browse
Supports PDF files up to 100MB
Need to verify if a PDF's digital signature is valid? iReadPDF's signature validator checks certificate-based signatures to confirm the signer's identity and verify the document hasn't been modified since signing.
Our validator examines the cryptographic signature, validates the certificate chain, and confirms document integrity. Get a clear report showing whether the signature is valid, who signed, when, and if any modifications were detected.
Why Use Our Validate PDF Signature Online for Free?
Who Uses This Tool?
Trusted by professionals across industries for their daily document needs
Contract Verification
Verify signed contracts are authentic. Confirm signer identities. Check for modifications.
Legal Evidence
Validate signatures for legal proceedings. Verify document authenticity. Confirm integrity for court.
Financial Audit
Verify financial document signatures. Audit trail validation. Confirm authorized signers.
Government Documents
Verify official government signatures. Validate permits and licenses. Confirm document authenticity.
Compliance Check
Verify signature compliance requirements. Validate required signatures present. Confirm proper signing.
Due Diligence
Verify documents in transactions. Validate authenticity before relying on documents. Risk assessment.
How It Works
Get started in three simple steps
Upload Signed PDF
Upload the PDF containing digital signature(s) to validate.
Automatic Validation
Our system validates all signatures, certificates, and document integrity.
View Report
Get detailed report on each signature: valid/invalid, signer info, timestamps.
Powerful Features
Everything you need, nothing you don't
Signature Verification
Cryptographically verify signature authenticity.
Integrity Check
Confirm document hasn't been modified since signing.
Certificate Validation
Validate certificate chain and trust.
Signer Information
Display signer identity from certificate.
Timestamp Verification
Validate trusted timestamps if present.
Multiple Signatures
Validate all signatures in multi-signed documents.
Frequently Asked Questions
Quick answers to common questions
What does "signature valid" mean?
The signature cryptographically matches the document content and was made with a valid certificate. The document hasn't been modified.
What if the signature shows as invalid?
The document may have been modified, the certificate may be expired/revoked, or the signature may be corrupted. Our report details the specific issue.
Does this verify simple drawn signatures?
No, this validates cryptographic digital signatures made with certificates. Drawn signatures cannot be cryptographically verified.
What about self-signed certificates?
We'll show the signature is cryptographically valid but note that the certificate isn't from a trusted authority.
Can I verify signatures from any Certificate Authority?
Yes, we validate signatures from all major CAs and report on certificate trust status.
What's shown in the validation report?
Validity status, signer name, organization, signing time, certificate details, modification status, and any warnings.
Related Tools You Might Like
Explore more PDF tools to streamline your workflow