Cryptography isn't your day job
PKCS#12, X.509, SHA-256, CAdES, PAdES — the standards are complex. One mistake in the implementation and the signature is invalid.
Back to overview Digital signatures
Sign PDFs. Via API. Legally binding.
Sign PDFs automatically with your PKCS#12 certificate. Add timestamps, verify existing signatures — all through the same REST API as your document generation.
1 credit per operation. 100 credits/month free.
Why digital signatures in software are hard
Manual signing doesn't scale
Adobe Acrobat, one employee, one document at a time. At 100 documents per day, you hit a wall.
Separate signing tools = broken workflow
Generate document in system A, sign in system B, store in system C. Three tools, three logins, three potential failure points.
Digital signing made simple
1
Provide certificate
Upload your PKCS#12 certificate (.p12/.pfx) or send it Base64-encoded in the API call.
2
Sign PDF
One API call with PDF and certificate. Optionally with timestamp, signing reason and location.
3
Verify signature
Check existing signatures for validity, integrity and certificate chain.
What you can do with it
PKCS#12 signing
Sign PDFs with .p12/.pfx certificates. Standards-compliant PAdES signatures.
Timestamps
TSA timestamps for provable signing times. Essential for legal requirements.
Verify signatures
Check existing signatures: validity, integrity, certificate chain, timestamps.
Visible signature
Optional visual signature field at a specific page and position.
Seamless integration
Generate a document and sign it in the same workflow. No export, no context switching.
Batch signing
Sign hundreds of documents automatically. Perfect for mass processing and bulk dispatch.
Perfect for
Contracts & agreements
Automated signing of employment contracts, NDAs and order confirmations right after generation.
Invoices & credit notes
Signed invoices for compliance requirements and audit-proof archiving.
Official documents
Signed notices, certificates and proof documents with legally valid electronic signatures.
Related glossary terms
Standards and formats directly related to this feature — explained concisely.
CAdES
ETSI standard for electronic signatures on binary files — built on top of CMS/PKCS#7, it signs arbitrary payloads like ZIPs, XML containers or binary formats.
PAdES
ETSI standard for electronic signatures in PDF documents — embeds the signature directly in the PDF, supports long-term validation and is eIDAS-compliant.
PKCS#12
Binary file format for bundling a private key and certificates under a single password — the de-facto format for signing certificates on servers and clients.
Qualified Electronic Signature (QES)
The highest assurance level of electronic signatures under the eIDAS regulation — legally equivalent to a handwritten signature, based on a qualified certificate and a secure signature creation device.
XAdES
ETSI standard for electronic signatures in XML documents — built on W3C XMLDSig, it signs invoices, government filings and business messages directly inside the XML stream.
Trusted Timestamp (TSA)
Cryptographic proof issued by a trusted third party that a document existed at a specific point in time — the foundation of long-term valid signatures and audit-safe archives.