Verify a PDF digital signature
Detect digital signature fields in a PDF and display the declared metadata (signer, date, reason). 100% local processing in your browser — your file never leaves your device.
Important, please read before use: this tool only detects the presence of a digital signature field and displays the information declared in the file (signer name, date, reason). It performs no real cryptographic verification: it checks neither the integrity of the document since signing, nor the validity or chain of trust of the certificate used. A signature shown here as "present" is therefore not guaranteed to be valid or authentic — for a complete trust verification, use a dedicated PDF reader (Adobe Acrobat Reader, for example).
How it works
This tool scans the PDF's form fields for signature-type fields, then reads the information the signature declared when it was created (signer name, date, reason, signature format). This information is displayed as is, with no additional validation.
Why doesn't it actually verify cryptographic validity?
Truly verifying a PDF signature (PKCS#7/CMS format) requires validating a certificate chain, checking a trusted certificate authority and confirming that the document content hasn't changed since signing — heavy cryptographic processing that goes beyond what's reasonable for a lightweight, 100% client-side tool. We'd rather say so clearly than let you believe this tool performs a trust verification that it doesn't.
The document shows "signed" — can I trust it?
Not on the basis of this tool alone: "signed" here means a signature dictionary is present with declared metadata, not that the signature has been verified as authentic and untampered. When trust really matters (a contract, a legal document), open the PDF in a reader that performs true certificate validation, such as Adobe Acrobat Reader.
100% local processing: signature fields are read entirely in your browser — your document is never sent to a server.