Verify Signatures
Check if digital signatures are valid
Digitally Sign PDF
Apply cryptographic digital signature
This tool processes your files entirely in your browser. Your documents never leave your device.
Certificate (.p12/.pfx)
Drop certificate file here
Import a PKCS#12 certificate for cryptographic signing
Create CertificateVisual Signature (Optional)
Create IdentitySettings
Visual signature shows identity info on the PDF. This is not a cryptographic signature.
Preview
Drag & drop PDF files here
or Browse Files
PDF•Max size: 100MB per file
About This Tool
Apply cryptographic digital signatures to PDF documents with our free online digital signing tool. Use your certificate (.p12/.pfx) to create verifiable signatures that can be validated by Adobe Acrobat Reader and other PDF applications.
Upload your digital certificate and apply a cryptographically signed signature. Recipients can verify the signature and confirm document integrity. Essential for legally binding digital documents and tamper-evident signing.
All digital signing happens locally in your web browser. Your certificate private key and documents never upload to external servers, ensuring maximum security for your signing credentials and confidential documents.
Perfect for legally binding contracts, regulatory submissions, official documents requiring verification, or any signing that needs cryptographic proof. Note: Verification depends on recipients trusting your certificate chain. Self-signed certificates display as untrusted in PDF readers.
Frequently Asked Questions
- Is Digitally Sign PDF free?
- Yes, completely free with no hidden costs, subscriptions, or usage limits. All tools are available at no charge.
- Is it safe to use Digitally Sign PDF?
- Yes, 100% safe. All processing happens locally in your browser. Your files are never uploaded to any server and never leave your device.
- What is the maximum file size?
- You can process files up to 100MB. Since everything runs in your browser, processing speed depends on your device.