Digital SignEnterprise
Digitally sign a PDF with a certificate — legally binding and tamper-evident. Enterprise plan required. Secure and fast.
How to Digital Sign
Upload your PDF
Select or upload your certificate
Sign the document
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.
Also known as: sign pdf online · sign pdf free · e-sign pdf · electronic signature pdf · digital signature pdf
How-to guide
Prefer the step-by-step version first?
Step-by-step instructions to digitally sign a pdf with a certificate — legally binding and tamper-evident with ZiaSign.
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.
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.
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.
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