Create Custom Redaction Handler in GroupDocs.Redaction .NET

Extend GroupDocs.Redaction capabilities with our format handling tutorials for .NET developers. In this hub you’ll learn how to create custom redaction handler and add new file format support, work with plain‑text documents, and programmatically handle diverse document types. These guides include ready‑to‑run C# examples, so you can quickly broaden the range of files your application can secure.

Quick Overview

  • What you’ll gain: Ability to redact custom content types and support additional file extensions without waiting for product updates.
  • Who it’s for: .NET developers building document‑centric solutions that require strict privacy controls.
  • Prerequisites: .NET 6+ (or .NET Framework 4.7.2+), a valid GroupDocs.Redaction license, and basic C# knowledge.

What is a custom redaction handler?

A custom redaction handler is a user‑defined component that tells GroupDocs.Redaction how to locate, interpret, and redact content that isn’t covered by the built‑in patterns. By implementing this handler you gain full control over proprietary data formats or unique business identifiers.

How to create custom redaction handler?

IRedactionHandler is an interface that defines the contract for custom redaction logic.
Redactor is the core class that manages redaction operations.
AddHandler registers a custom handler with the Redactor instance.
Redact executes the redaction based on the configured handlers.

Load the Redaction engine, register your handler, and invoke the redaction process – all in three concise steps. First, implement the IRedactionHandler interface with logic that scans the document for your custom tokens. Then, add the handler to the Redactor instance via AddHandler. Finally, call Redact to apply the changes. This pattern works for PDFs, images, and any supported format, allowing you to protect data that standard patterns miss.

How to add new file format?

SupportedFormats is a collection that holds the file extensions recognized by the Redaction engine. Register a new file extension with the Redaction engine by extending the SupportedFormats collection. Provide a parser that converts the incoming file into a format GroupDocs.Redaction can process, then map the extension to your parser. Once registered, the engine treats the new format like any native type, enabling seamless redaction across the board.

Why use GroupDocs.Redaction for custom format handling?

GroupDocs.Redaction supports 70+ input and output formats and can process files up to 2 GB without loading the entire document into memory, delivering high‑throughput redaction in enterprise environments. Its extensible architecture lets you plug in custom handlers in under 30 minutes, reducing development time and eliminating the need for third‑party preprocessing tools.

Available Tutorials

Extend File Types in GroupDocs.Redaction .NET: A Step‑By‑Step Guide to Custom Extensions

Learn how to extend supported file types with custom extensions using GroupDocs.Redaction for .NET, ensuring secure document redaction across diverse formats.

Implementing Supported File Format Listing with GroupDocs.Redaction .NET

Learn how to use GroupDocs.Redaction .NET to list supported file formats, streamline document management systems, and optimize performance.

Additional Resources

Last Updated: 2026-07-15
Tested With: GroupDocs.Redaction 23.12 for .NET
Author: GroupDocs