# PDF PAdES Certificate Signer

Sign PDFs with a PKCS#12 certificate using an ETSI CAdES detached signature.

> Canonical page: https://elysiatools.com/en/tools/pdf-pades-certificate-signer

- **Category:** PDF Tools

- **Keywords:** pdf, PAdES, digital signature, PKCS#12, certificate, CAdES

## Overview

Adds a certificate-backed ETSI.CAdES.detached signature, optionally with a visible block, and rejects already signed PDFs.

## Inputs

- **PDF File** (file): Upload an unsigned PDF
- **PKCS#12 Certificate** (file): Upload a .p12 or .pfx bundle
- **Certificate Password** (text): Password for the P12/PFX bundle
- **Signer Name** (text): Name shown in the signature dictionary
- **Signature Reason** (text)
- **Signature Location** (text)
- **Contact Information** (text)
- **Visible Signature** (checkbox)
- **Page Number** (number)
- **Signature X** (number)
- **Signature Y** (number)
- **Signature Width** (number)
- **Signature Height** (number)
- **Placeholder Length** (number)

## When to use

- Sign an unsigned PDF with a .p12 or .pfx certificate.
- Add a visible approval block with a signer name, reason, location, and contact information.
- Attach an invisible certificate-backed signature for audit or document workflows.

## How it works

- Upload the unsigned PDF and a PKCS#12 certificate bundle.
- Enter the certificate password when the bundle is protected and provide the required signer name.
- Choose the signature reason and optional location or contact information.
- Enable or disable the visible signature block, then set its page, position, and dimensions if needed.

## Use cases

- Approve contracts, forms, and internal documents with a certificate-backed PDF signature.
- Add a visible signer block to show approval details on a specific PDF page.
- Create an invisible signed PDF for audit trails without drawing a signature block over the document.

## Frequently asked questions

### What certificate formats are supported?

The tool accepts PKCS#12 certificate bundles in .p12 or .pfx format.

### Can I sign a PDF that already has a signature?

No. PDFs that are already signed are rejected.

### Is the signature visible on the PDF page?

Yes, by default. You can disable the visible signature block for an invisible certificate signature.

### Which signer details can I add?

A signer name is required. You can also add a signature reason, location, and contact information.

### Where is a visible signature placed?

Set the page number and the signature X, Y, width, and height values.

## Related tools

- [PDF Digital Signature PAdES and Trust Chain Validator](https://elysiatools.com/en/tools/pdf-digital-signature-pades-and-trust-chain-validator): Audit PDF signatures, PAdES baseline evidence, certificate chains, DSS, revocation material and timestamps offline.
- [PDF Signature Verify](https://elysiatools.com/en/tools/pdf-signature-verify): Verify digital signatures in PDF documents
- [PDF Form Fill Batch](https://elysiatools.com/en/tools/pdf-form-fill-batch): Fill one PDF form template with an array of records and output one filled PDF per record (ZIP) or a merged PDF
- [Convert GIF to PDF](https://elysiatools.com/en/tools/gif-to-pdf): Convert GIF images to PDF format with support for both single-frame and multi-frame animations
- [PDF Photo Contact Sheet](https://elysiatools.com/en/tools/pdf-photo-contact-sheet): Generate paginated photo contact sheets with thumbnails, filenames, and EXIF lines
- [PDF Storyboard Sheet](https://elysiatools.com/en/tools/pdf-storyboard-sheet): Generate storyboard sheets with thumbnail frames and description areas
- [Convert TIFF to PDF](https://elysiatools.com/en/tools/tiff-to-pdf): Convert TIFF images to PDF format with customizable page size, orientation, and compression settings
- [PDF Add Signature Online](https://elysiatools.com/en/tools/pdf-add-signature-online): Add a visible typed or image signature block to selected PDF pages and download the signed copy

## Samples

- [PDF Samples](https://elysiatools.com/en/samples/pdf-samples): Generated PDF samples from tools dated 2026-02-01 to 2026-02-10
- [Markdown Slide Deck Samples](https://elysiatools.com/en/samples/md-slide-deck-to-pdf): Remark/Marp style Markdown slide decks for testing PDF export layouts
- [SSL Certificate Management Samples](https://elysiatools.com/en/samples/cert-manager-samples): SSL certificate management examples including Let's Encrypt automation, certificate renewal, monitoring, and security best practices
- [Time Zone Workflow Scheduler ICS Samples](https://elysiatools.com/en/samples/time-zone-workflow-scheduler-ics-samples): ICS files generated in the same structure returned by the Time Zone Workflow Scheduler, with multiple VEVENT meeting candidates exported from overlap windows

## Related content

- [PDF Signing, Stamping, and Distribution Tracing](https://elysiatools.com/en/hubs/pdf-signing-stamping-and-distribution-tracing): Send PDFs you can prove are yours — redact sensitive content permanently before sealing, add a visible signature block and a PAdES certificate signature, stamp the document status, embed invisible per-recipient tracking IDs, and audit incoming signatures down the certificate chain.