How to Digital Sign Online
Step-by-step instructions to digitally sign a pdf with a certificate — legally binding and tamper-evident with ZiaSign.
Why this workflow matters
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.
Step by step
Digital Sign is one of the fastest ways to digitally sign a pdf with a certificate — legally binding and tamper-evident. Enterprise access gives you the full workflow.
- 1
Upload your PDF
- 2
Select or upload your certificate
- 3
Sign the document
- 4
Download the signed PDF
Frequently asked questions
How 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.
Is a digitally signed PDF legally valid?
Yes. Digital signatures with certificates comply with eIDAS, ESIGN Act, and other international e-signature laws.
What'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.
More specific workflows for this tool
Related guides
How to Add Signature Field Online
Step-by-step instructions to add empty digital signature fields to a pdf for recipients to sign with ZiaSign.
Read guideHow to Add Timestamp Online
Step-by-step instructions to add a trusted timestamp to a pdf document with ZiaSign.
Read guideHow to Remove Signatures Online
Step-by-step instructions to remove all digital signatures from a pdf with ZiaSign.
Read guideReady to run the actual workflow?
You have the steps. Open the tool, process the file, and then move into the next recommendation if the document still needs cleanup, protection, or conversion.