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Digital SignEnterprise

Digitally sign a PDF with a certificate — legally binding and tamper-evident. Enterprise plan required. Secure and fast.

Secure processing
Files deleted after 1 hour

How to Digital Sign

1

Upload your PDF

2

Select or upload your certificate

3

Sign the document

4

Download the signed PDF

Frequently Asked Questions

1How do I digitally sign a PDF online?

Upload your PDF to ZiaSign, select or upload your digital certificate, apply the signature, and download the signed document. Legally binding.

2Is a digitally signed PDF legally valid?

Yes. Digital signatures with certificates comply with eIDAS, ESIGN Act, and other international e-signature laws.

3What's the difference between digital and electronic signature?

A digital signature uses a cryptographic certificate for tamper-evidence and identity verification. An electronic signature is any electronic indication of intent to sign.

Why Use ZiaSign's Digital Sign Tool?

ZiaSign's digital signature tool lets you sign PDF documents with a cryptographic certificate. Legally binding, tamper-evident, and compliant with eIDAS, ESIGN Act, and international e-signature laws. Trusted by enterprises worldwide.

Sign with cryptographic digital certificate
Legally binding and tamper-evident
Compliant with eIDAS and ESIGN Act
Upload or select your certificate

Also known as: sign pdf online · sign pdf free · e-sign pdf · electronic signature pdf · digital signature pdf

Popular Ways to Use Digital Sign

Jump straight to the query-specific guide that matches what you are trying to do, then open the tool when you are ready.

Digitally Sign NDA Documents

Apply legally binding digital signatures to non-disclosure agreements

Open guide

Digitally Sign Lease Agreements

Execute lease and rental agreements with legally binding digital signatures

Open guide
Browse all 139 use-case guides

Why teams stay with ZiaSign after the first quick fix

The strongest tool pages do not just solve one file problem. They make the next document task easier to start and easier to trust.

Secure file handling by default

Files are processed securely and automatically deleted after 1 hour so quick PDF jobs do not turn into storage risk.

118 tools and 139 workflow guides

Start with a single tool page, then move into guided document tasks without leaving the platform.

Free to start, deeper when the workflow grows

Anonymous tools cover quick fixes, while accounts, Pro, and Enterprise plans support heavier document operations.

Related PDF Tools

Add Signature Field
Remove Signatures
Add Timestamp
Validate Timestamp
Certify PDF
Merge PDF
View all 118 tools

118+

Free PDF Tools

100%

Browser-Based

No

Installation Needed

SOC 2

Compliant Security

Trusted by thousands of professionals worldwide. All files are processed securely in your browser or encrypted servers and automatically deleted.

Planning team-wide document workflows?

Talk to ZiaSign about volume pricing, security review, approvals, and enterprise rollout for document-heavy teams.

Contact Enterprise SalesView Pricing

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