Digital Signature
Add X.509 digital signatures to PDF documents. Sign PDFs with PFX, P12, or PEM certificates for legal validity.
What this tool is best for
Add X.509 digital signatures to PDF documents. Sign PDFs with PFX, P12, or PEM certificates for legal validity.
Why people use it
- Focused workflow for Digital Signature without requiring users to piece the job together across multiple tools.
- Fits access control, privacy, and document security tasks where users want a direct outcome instead of a general editor.
- Connects naturally with Validate Signature when the document workflow needs a clear next step.
What to watch for
- Best when the task is specifically digital signature; if the job changes, Validate Signature may be the better route.
- Results still depend on source-file quality, browser resources, and how complex the document structure is.
Supported inputs
PDF files, single-file workflow, digital signature source documents
Common outputs
processed PDF output, digital signature result ready for download, share-ready final file
About This Tool
Digital Signature allows you to add cryptographic X.509 digital signatures to PDF documents. Unlike simple drawn signatures, digital signatures provide legal validity and document integrity verification.
Upload your certificate file (PFX, P12, or PEM format), enter the password, and sign your PDF. You can add visible signatures with custom text, images, and positioning, or invisible signatures for document integrity only.
All signing happens locally in your browser. Your certificate and documents are never uploaded to any server.
How to Use
Upload PDF
Upload the PDF document you want to digitally sign.
Load Certificate
Upload your X.509 certificate file (.pfx, .p12, or .pem) and enter the password.
Configure Signature
Optionally add reason, location, and visible signature with custom text or image.
Sign and Download
Click Sign PDF to apply the digital signature and download the signed document.
Use Cases
Legal Documents
Sign contracts, agreements, and legal documents with legally binding digital signatures.
Business Approvals
Digitally sign invoices, purchase orders, and approval documents for audit trails.
Document Integrity
Ensure documents have not been tampered with after signing.
Frequently Asked Questions
What certificate formats are supported?
PFX (.pfx), PKCS#12 (.p12), and PEM (.pem) certificate formats are supported.
Is the signature legally valid?
Yes, X.509 digital signatures are legally recognized in most jurisdictions when using a valid certificate.
Can I add a visible signature?
Yes, you can add a visible signature with custom text, image, position, and styling.
You May Also Like
Verify digital signatures in PDF documents. Check certificate validity, signer information, and document integrity.
Encrypt PDF files with a password and control who can open, print, or copy them. Add PDF protection online before sharing sensitive documents.
Sign PDF online by drawing, typing, or uploading a signature. Place signatures on contracts, forms, and approval documents without printing or scanning.