Cryptographically verify a PDF's digital signatures: check the signature is intact, whether the document was modified after signing, and validate the signer's certificate chain. Runs locally — your file never leaves your device.
Upload a signed PDF (optionally add a trust-anchor PEM)
The tool checks each signature's cryptographic integrity, document coverage, and certificate chain
Review per-signature verdicts: intact, covers-whole-document, and trusted
Free is enough for most one-off jobs. Pro raises the file and batch caps; Pro + Media unlocks GB-scale streaming and unlimited duration.
Larger files supported on Developer (5 GB CSV) and Enterprise (unlimited). All processing happens in your browser — files never reach a server.
0 bytes uploaded. PDF Signature Verifier runs entirely in your browser using pdf-lib and pdfjs-dist. Your file stays on your device at all times. No data is sent to any server.
For each embedded signature it recomputes the digest over the signed ByteRange and verifies the PKCS#7/CMS signature against the signer certificate (RSA and ECDSA, SHA-256/384/512). It reports whether the signature is intact, whether the signature covers the whole document (detecting bytes appended after signing), and — when you supply trust anchors — whether the signer's certificate chains to a trusted root within its validity window.
Yes. If any byte inside the signed range was changed, the digest no longer matches and the signature is reported as not intact. If extra bytes were appended after the last signature, the signature is intact but flagged as not covering the whole document.
Not in this version. It validates the certificate chain and validity dates but does not perform live OCSP or CRL revocation lookups. For full revocation and long-term-validation (LTV) checking, use a desktop tool such as Adobe Acrobat or the open-source pyHanko.
No — this verifies existing signatures. To add a cryptographic signature use the PDF Digital Signature tool, or the PDF Sign tool for a visible (non-cryptographic) signature mark.
View and validate digital signatures embedded in PDF documents. Check who signed and when.
Open toolDraw or type a signature and place it on any page of a PDF. Simple, private, browser-based signing.
Open toolRemove author, title, producer, creation date, and all metadata from a PDF. Essential for privacy before sharing.
Open tool