Digital Signature for PDF
Certificate-based PAdES signature (.p12).
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Add a digital signature to a PDF with a .p12 or .pfx certificate, on your phone or computer. The PAdES signature proves who signed and reveals later changes; this tool is available with a subscription.
How to add a digital signature to a PDF
- 1Select a PDF file.
- 2Choose your certificate file (.p12 or .pfx) and enter its password.
- 3Add a reason and location if you like.
- 4Press the sign button and download the digitally signed PDF.
Why Sahl PDF?
- PAdES signatures, the standard for PDF
- Proves who signed and reveals edits made afterwards
- Optional reason and location fields
- Encrypted upload; file and certificate deleted right away
Frequently asked questions
Digital signature or electronic signature — what's the difference?
A regular e-signature is an image on the page. A digital signature uses a certificate that proves the signer's identity and reveals any change made after signing.
Where do I get a digital certificate?
Certificates are issued by accredited certificate authorities or by your organization, usually as a .p12 or .pfx file with a password.
Is digital signing free?
Certificate-based signing is a subscriber feature, available with a low-cost subscription.
How can I check the signature?
Use Verify signatures to see who signed, when, and whether the file changed afterwards.
Is my certificate stored after signing a PDF?
No. The PDF and certificate are uploaded encrypted and deleted right after signing.
Will my digital signature show as valid in PDF readers?
Readers show it as trusted when your certificate comes from an authority they trust. Self-signed certificates appear as valid but untrusted.