Digital Sign PDF Free Online

Add a cryptographic digital signature to your PDF using a certificate (PFX/P12 or PEM). Ensures document authenticity and integrity.

1. Select PDF to Sign

Click to select or drag and drop

PDF file

How It Works

1

Upload PDF

Select the PDF document you want to sign

2

Add Certificate

Upload your PFX/P12 or PEM certificate

3

Download Signed

Get your digitally signed PDF

Why Choose SwiftPDFLab for Digital Signing?

100% Private

Your certificate and documents never leave your device. All signing happens locally.

Standards Compliant

Creates PDF signatures compatible with Adobe Reader and other PDF viewers.

Visible Signatures

Option to add visible signature with your custom image and text.

Multiple Formats

Supports PFX/P12 and PEM certificate formats.