Sign with Certificate
Sign PDF with a digital certificate
Certificate-based Digital Signature (PKCS#7)
Embeds a cryptographically verifiable signature using your X.509 certificate. Adobe Acrobat will show the signature as valid if the certificate is trusted (issued by a trusted CA or imported). Self-signed certificates are shown as "valid signature, unknown trust".
1 — PDF to Sign
Drop PDF here
2 — Certificate
Drop a .p12 or .pfx certificate
3 — Signature Details
The signature field is invisible (metadata only). The page number only affects which page the annotation is attached to.
Your certificate and private key are processed server-side and never stored.
Features
- ✓Digital certificate (P12/PFX, PEM)
- ✓PAdES standard
- ✓Keeps earlier signatures
About Sign with Certificate
Sign PDF with a digital certificate Sign with Certificate works in your browser — it is free and needs no software or sign-up.
How to use Sign with Certificate
- Upload or drag & drop your PDF file into the area above.
- Adjust the available options to fit your needs.
- Click the process button and wait a moment.
- Download your result instantly.
Frequently asked questions
Is Sign with Certificate free?
Yes. Sign with Certificate is completely free and you can use it right away without creating an account.
Are my files safe?
Your files are used only to complete the task. They are never sold, shared or used for anything else, and they are deleted automatically.
Do I need to install any software?
No. All you need is a browser: you upload the file, our servers process it and send the result back.
How does Sign with Certificate work?
Sign PDF with a digital certificate