Sign PDF

Digitally sign PDFs with a certificate from a Windows USB signing key.

Connect the USB signing key and make sure its Windows driver or token middleware is installed. This page does not read a normal USB drive directly. It only lists signing certificates that Windows has already loaded from a cryptographic token into the Personal certificate store. Your private key remains on the device, and the token software may open a secure PIN prompt while signing.

Sign with a USB certificate

Create an Adobe-compatible cryptographic signature using a certificate in the Windows Personal store.

PDF document

Drag and drop a PDF here, or click to select

Maximum size: 100 MB

Certificate from USB signing key

Reason for signing (optional)

Location (optional)

This local integration currently supports Windows certificate-store tokens. It does not upload the certificate, PIN, PDF, or private key to an external service.

How to use Sign PDF

Digitally sign PDFs with a certificate from a Windows USB signing key. The tool is designed for a focused workflow without account setup or unnecessary steps.

1
Provide the input
Choose the file or enter the information requested by the tool.
2
Choose your settings
Review the available controls and configure the result you need.
3
Finish the task
Download, copy, or review the completed result in your browser.

Frequently asked questions

Is Sign PDF free to use?

Yes. Sign PDF is available free online and does not require an account.

How does Sign PDF process my files?

The page explains when an advanced operation needs the site's processing service. Browser-only steps remain on your device.

What do I need to use Sign PDF?

Use Windows with the signing token's driver or middleware installed. The certificate must be available in the Windows Personal certificate store.

How to use Sign PDF

Provide the input

Choose your settings

Finish the task

Frequently asked questions

Is Sign PDF free to use?

How does Sign PDF process my files?

What do I need to use Sign PDF?