- How do I verify a digital signature in a PDF online?
- Upload the signed PDF to this free tool. It automatically detects digital signatures, verifies their integrity, extracts signer identity and certificate details, and checks whether the document was modified after signing. Results appear in seconds with no software installation required.
- What information does the PDF Signature Checker show?
- The tool displays signer name and identity fields from the certificate, certificate issuer details, signing date and timestamp, signature validity status, and document integrity indicators showing whether the PDF content was modified after the signature was applied.
- Can this tool detect if a signed PDF was tampered with?
- Yes. The tool checks document integrity by comparing the cryptographic hash embedded in the signature against the current document content. If the document was modified after signing, the integrity check will flag the discrepancy, indicating potential tampering or unauthorized changes.
- Does this replace Adobe Acrobat signature verification?
- This tool provides excellent first-pass signature verification including integrity checks and signer identity extraction. However, full trust-chain validation against enterprise certificate authorities and Adobe’s AATL may require Adobe Acrobat or dedicated PKI validation software. Use this tool for quick screening and Adobe for final compliance decisions.
- Is my signed PDF data safe when using this verification tool?
- Yes. All signature analysis and verification happens locally in your browser using client-side JavaScript. Your PDF is never uploaded to any server, making it safe for confidential legal documents, financial statements, government filings, and sensitive business agreements.
- What types of PDF digital signatures does this tool support?
- The tool supports standard PDF digital signatures based on PKCS#7 and CMS (Cryptographic Message Syntax) formats. These are the signature formats used by Adobe Acrobat, DocuSign, GlobalSign, DigiCert, and most enterprise document signing platforms.
- What does it mean if no signature is found in my PDF?
- A ‘no signature found’ result means the PDF does not contain embedded digital signatures. The document may have been electronically signed with a visual signature image (which is not a cryptographic digital signature) or may not have been signed at all. Verify with the document sender whether a digital signature was intended.
