PDF Signature Checker

Verify the signatures of a PDF file to determine whether the contents have been altered since signing

PDF Signature Checker

Verify digital signatures in PDF documents

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Drag & drop your PDF file here

or click to browse • Supports PDF files with digital signatures

Privacy First

All PDF analysis is performed locally in your browser. Your files are never uploaded to any server. This tool extracts and displays signature information without modifying your documents.

Tool Features

This tool provides comprehensive PDF signature analysis with the following capabilities:

PDF Basic Information Extraction

  • Page count
  • Title
  • Author
  • Creator
  • Creation date
  • Modification date

Digital Signature Detection

Parses signature objects from raw PDF bytes to detect all embedded digital signatures.

Signature Details Extraction

  • Signature type (SubFilter: adbe.pkcs7.detached, ETSI.CAdES, etc.)
  • Signing date
  • Signing reason
  • Signing location
  • ByteRange information

Certificate Information Parsing

  • Certificate Subject
  • Certificate Issuer
  • Serial Number
  • Validity Period (start/end dates)
  • Certificate expiration status
  • Signature algorithm

About PDF Digital Signatures

PDF digital signatures are a type of electronic signature that uses cryptography to ensure document authenticity and integrity. When a PDF is digitally signed, a unique fingerprint (hash) of the document is created and encrypted with the signer's private key.

Key aspects of PDF digital signatures:

  • Document Integrity: Any change to the document after signing will invalidate the signature
  • Signer Authentication: Digital certificates verify the identity of the signer
  • Non-repudiation: Signers cannot easily deny their signature, as it requires their private key
  • Timestamping: Provides proof of when the document was signed

Common Use Cases:

  • Legal documents and contracts
  • Financial statements and reports
  • Government forms and applications
  • Medical records and prescriptions
  • Technical documentation and certification

It's important to note that PDF signatures can be configured in different ways. Some signatures allow specific types of changes after signing (like form filling), while others lock the entire document. This tool checks if the document has been modified in ways not permitted by the signature.