Certificate Sign PDF Online
Sign a PDF with a digital certificate using a compatible PKCS#12 (.p12 or .pfx) certificate.
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Supported Formats:PDFP12PFX
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Certificate Sign PDF Online
Use this certificate sign PDF tool to digitally sign PDF documents with a compatible digital certificate. You can sign PDF files using a PKCS#12 certificate such as a .p12 or .pfx file and create a certificate-based digital signature.
If you are looking for how to digitally sign a PDF with a certificate, upload your document and certificate above. The workflow is designed for PDF signing with digital certificates, including certificate-based document signing and digital signature workflows.
How to Convert Files to and from PDF
Choose a file
Upload the PDF document you want to digitally sign.
Convert online
Upload your PKCS#12 digital certificate (.p12 or .pfx).
Download
Enter the certificate password when required.
Step 4
Apply the digital certificate signature to the PDF.
Step 5
Download the digitally signed PDF document.
Related PDF Signing Tools
Why Choose FreePDFConvert?
Free PDF conversion and document tools designed to help you convert, manage and work with PDF files from any device.
PKCS#12 (.p12) and PFX Certificate Support
X.509 Certificate-Based Signatures
SHA-256 Cryptographic Signing
Tamper-Evident PDF Signature
Certificate Password Protection
Browser-Based PDF Signing
No PDF Installation Required
How to Digitally Sign a PDF With a Certificate
A certificate-based PDF signature uses digital certificate technology to associate a signature with a certificate and help verify whether the signed PDF has been modified after signing. This is different from simply drawing an image of a signature onto a PDF.
Sign PDF With a Digital Certificate
For certificate-based PDF signing, you typically need the PDF document, a compatible digital certificate, and the certificate password if the certificate is protected. PKCS#12 certificate containers commonly use the .p12 or .pfx file extension.
PDF Signing Certificate and Digital Signatures
A digital certificate can be used as part of a cryptographic PDF signature. Certificate-based signing is useful when a document needs stronger signer authentication and protection against undetected changes after signing.
Frequently Asked Questions
How do I digitally sign a PDF with a certificate?
Upload your PDF, provide your PKCS#12 digital certificate (.p12 or .pfx), enter the certificate password when required, and apply the certificate signature. You can then download the digitally signed PDF.
What is a certificate-based PDF signature?
A certificate-based PDF signature uses a digital certificate to cryptographically sign a PDF. The certificate can help verify the signer and detect changes made to the document after signing.
Can I sign a PDF with a digital certificate?
Yes. This tool is designed for certificate-based PDF signing using supported PKCS#12 certificate files such as .p12 and .pfx.
What certificate formats can I use to sign a PDF?
This tool supports standard PKCS#12 certificate containers, including .p12 and .pfx files. Your certificate may contain an X.509 certificate and its corresponding private key.
What is the difference between eSign PDF and certificate signing?
An electronic signature can represent a person’s approval or intent to sign. A certificate-based digital signature uses cryptographic certificate technology to help authenticate the signer and detect document changes.
Can I digitally sign a PDF with a PFX certificate?
Yes, when the PFX file contains a compatible certificate and private key. Upload the PDF and PFX certificate, then provide the certificate password when required.
Can I digitally sign a PDF with a P12 certificate?
Yes. PKCS#12 .p12 certificate files are supported for certificate-based PDF signing when they contain the required certificate and private key.
Will a certificate-signed PDF show that the document was changed?
A properly implemented digital signature can help detect changes made after signing. The exact validation result depends on the certificate, signature format, PDF viewer, and document changes.
Is Certificate Sign PDF free?
The certificate PDF signing tool is available online for free, subject to the current limits and capabilities of the service.