Sign with Certificate
Add a digital signature using a certificate
Drop your PDF here or click to browse
Supports PDF files up to 100MB
Add legally binding digital signatures to your PDFs using digital certificates. ConvertedPDF's certificate signing tool lets you apply cryptographic signatures that verify your identity and detect any tampering—meeting the highest standards for digital document authentication.
Unlike simple electronic signatures (drawing your name), certificate-based signatures use PKI cryptography to prove who signed and that the document hasn't been modified. Required for many legal, government, and enterprise documents.
Why Use Our Sign PDF with Digital Certificate?
Who Uses This Tool?
Trusted by professionals across industries for their daily document needs
Legal Documents
Sign contracts with legal validity. Authenticate legal filings. Create enforceable signatures.
Government Submissions
Sign documents for government agencies. Meet regulatory signature requirements. Authenticate official forms.
Financial Documents
Sign financial agreements. Authenticate banking documents. Create audit-trail signatures.
Healthcare
Sign medical authorizations. Authenticate prescriptions. Meet HIPAA signature requirements.
Enterprise Workflows
Sign internal documents with company certificates. Authenticate approvals. Enable verified workflows.
International Documents
Sign with internationally recognized certificates. Cross-border document authentication. EU eIDAS compliance.
How It Works
Get started in three simple steps
Upload PDF
Upload the document you need to sign with a digital certificate.
Add Certificate
Upload your digital certificate (PFX/P12) and enter the password.
Sign & Download
Apply the signature and download your cryptographically signed PDF.
Powerful Features
Everything you need, nothing you don't
Certificate Support
Works with PFX, P12, and other standard certificate formats.
Visible or Invisible
Add visible signature appearance or invisible cryptographic seal.
Tamper Detection
Signature invalidates if document is modified.
Timestamp Option
Add trusted timestamp to prove signing time.
Multiple Signatures
Document can be signed by multiple parties.
LTV Support
Long-term validation for permanent verifiability.
Frequently Asked Questions
Quick answers to common questions
What's the difference from regular PDF signing?
Regular signing draws your signature visually. Certificate signing uses cryptographic proof of identity that can be verified and detects any tampering.
Where do I get a digital certificate?
From Certificate Authorities like DigiCert, GlobalSign, or government-issued IDs with signing capability. Some countries issue them with national IDs.
Is this legally binding?
Certificate-based signatures are legally recognized in most jurisdictions including EU (eIDAS), US (ESIGN), and many others.
Will the signature be validated in Adobe Reader?
Yes, Adobe Reader and other PDF software will validate the signature and show signer identity.
What if my certificate expires?
Signatures made before expiry remain valid. Use timestamping to prove the signature was made during validity period.
Can multiple people sign the same document?
Yes, each person adds their signature with their certificate. All signatures are independently verifiable.
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