PDF signatures → JSON

Detect signatures from a PDF (PAdES / PKCS#7), retrieve technical information (ByteRange, SubFilter…) and export it as JSON, locally in your browser.

Import a PDF

No data is sent to a server: everything is done in your browser.

← Back to PDF tools

Use cases

Audit of signed documentsInventory the present signatures, their position (fields), and certificate information.
Compliance CheckVerify that a PDF contains the expected fields/signatures before archiving or sending.
Debugging an invalid signatureUnderstand why a signature appears broken (modification, merging, flattening, adding pages…).
Workflow integrationExport a JSON to feed a tracking system (signature received, date, signer, reason).

What you get

A JSON of signatures: fields, subtype, signer name (if present), reason, location, date, byte range, and certificate info.

Useful elements to correlate with your actions: presence of timestamp, number of signatures, empty fields to sign.

Limitations and points of attention

Complete cryptographic validation depends on a chain of trust (CA) and a verification environment: JSON alone is not always sufficient.
Some information (name, reason) may be absent or non-standard depending on the signing software.
Modifying the PDF after signing (merging, sanitization, flattening…) may invalidate the signature.

Frequently asked questions

Does the tool indicate if the signature is valid?

It mainly provides data and indicators. Strict validity may require cryptographic verification and a chain of trust.

Why does my signature become invalid after merging?

A signature covers a specific byte range: any modification of the file changes the bytes and breaks the signature.

Can there be multiple signatures?

Yes. A PDF can contain multiple fields and incremental signatures.

Tip

In a workflow, perform all transformations (merge/split/flatten/sanitize) before the final signature. After signing, avoid any modification of the file.