macOS app for PDF signing

PAdES Studio

Sign and verify PDF documents locally on macOS using digital certificates available in Keychain. The app writes a standard PDF signature field and supports visible signatures, RFC 3161 timestamping, and PAdES-oriented validation data.

PAdES-B-B to B-LTAmacOS KeychainLocal processing

Digitally signed PAdES-B-LT
RFC 3161 timestamp

Built for real PDF digital signatures, not just a visible stamp.

PAdES Studio writes signatures as incremental PDF updates so the original document bytes are preserved and existing signatures can remain verifiable.

Keychain signing

Select a signing identity from macOS Keychain and sign with a private key that remains under system control.

Visible signature

Add an optional page area, signature image, signer name, and signing time without changing the cryptographic signature model.

Timestamping and LTV

Use RFC 3161 timestamps and embed certificates, OCSP responses, or CRLs in the PDF Document Security Store when available.

Signature inspection

Review signature status, certificate chains, timestamps, DSS/VRI material, and detected or validated PAdES profiles.

Multiple signatures

Add another signature as a new document revision. Existing signatures are not rewritten and remain independently verifiable.

Local documents

PDF files are not processed on the developer's server. Network access is used only for optional TSA, OCSP, or CRL requests.

From opening a PDF to a verifiable signature.

The app supports everyday signing as well as archival workflows where timestamps and validation data matter.

Step 1

Open a PDF

Open a document from the File menu, Open Recent, or by dragging it into the app window.

Step 2

Select an area

Mark a place on the page for a visible signature, or skip selection for an invisible digital signature.

Step 3

Choose a profile

Select the identity, metadata, PAdES profile, timestamp server, and LTV options required by the document.

Step 4

Sign and verify

Save the signed copy, then inspect the signature status, certificates, and validation notes.

Supported PAdES-oriented outputs.

Higher profiles need more external data. The app reports when timestamps or long-term validation material cannot be obtained.

PAdES-B-BBaseline detached CAdES signature embedded in a PDF signature field.

PAdES-B-TA signature with an RFC 3161 signature timestamp from the configured TSA.

PAdES-B-LTDSS/VRI material with certificates, OCSP responses, or CRLs when the certificate chain provides them.

PAdES-B-LTAAn archive document timestamp covering the revision after the DSS/VRI update.

Documents stay local.

PAdES Studio does not use a developer-operated server to process PDFs. Timestamping and LTV may contact only endpoints you configure or endpoints published in certificates.