---
title: "Redact a Word document in C#"
url: https://recursiveai.org/onedocument/cookbook/redact-word-document/
description: "Redact a Word document in C# with OneDocument: free, open-source .NET code, a runnable example and the actual output."
version: "1.0.0"
---

# Redact a Word document in C#

**OneDocument** is a free, open-source Word, Excel and PowerPoint document library for .NET from Recursive AI. MIT or Apache-2.0, no native dependencies.

[NuGet](https://www.nuget.org/packages/RecursiveAI.OneDocument.Documents) · [GitHub](https://github.com/recursive-ai-oss/onedocument-csharp) · [Docs](https://recursiveai.org/onedocument/docs/) · [Download example (.zip)](https://recursiveai.org/onedocument/cookbook/redact-word-document/redact-word-document.zip)

Redaction replaces sensitive content in the document file, rather than just hiding it on screen.

```shell
dotnet add package RecursiveAI.OneDocument.Documents
```

Requires [.NET 10](https://dotnet.microsoft.com/download/dotnet/10.0) (net10.0); .NET 9 and earlier aren’t supported.

`client.docx` is in the zip, or you can use your own `.docx` file.

```csharp
using RecursiveAI.OneDocument.Documents;
using RecursiveAI.OneDocument.Redaction;

using var doc = Document.Open("client.docx");
var plan = new RedactionPlan();
plan.Matches.Add(
    RedactionMatch.Literal("Jane Doe"));
var report = doc.Redact(plan, "redacted.docx");
Console.WriteLine($"Verified: {report.Verified}");
```

```text
Verified: True
```

Unzip [the example](https://recursiveai.org/onedocument/cookbook/redact-word-document/redact-word-document.zip), then `dotnet run`.

`client.docx` is in the zip. Its body reads “Client: Jane Doe” and “Status: approved”. The full program recreates this input.

## The full program

The download’s `Program.cs` uses the supplied samples:

```csharp
using RecursiveAI.OneDocument.Documents;
using RecursiveAI.OneDocument.Redaction;

using (Document sample = Document.Create())
{
    sample.Body.AddParagraph("Client: Jane Doe");
    sample.Body.AddParagraph("Status: approved");
    sample.SaveAs("client.docx");
}
using Document doc = Document.Open("client.docx");
var plan = new RedactionPlan();
plan.Matches.Add(RedactionMatch.Literal("Jane Doe"));
var report = doc.Redact(plan, "redacted.docx");
Console.WriteLine($"Verified: {report.Verified}");
using Document result = Document.Open("redacted.docx");
foreach (Paragraph paragraph in result.Paragraphs)
    Console.WriteLine(paragraph.Text);
```

`dotnet run` prints:

```text
Verified: True

Client: ████████
Status: approved
```

If content survives, the report has `Verified = false` and lists survivors; do not release that output.

This operation has not been independently audited.

## Variations

### Match a normal or nonbreaking space

```csharp
using RecursiveAI.OneDocument.Documents;
using RecursiveAI.OneDocument.Redaction;

using var doc = Document.Open("client.docx");
var plan = new RedactionPlan();
plan.Matches.Add(RedactionMatch.Pattern("Jane[ \u00A0]Doe"));
var report = doc.Redact(plan, "pattern-redacted.docx");
Console.WriteLine($"Verified: {report.Verified}");
```

Output:

```text
Verified: True
```

## Related recipes

- [Read a Word document](https://recursiveai.org/onedocument/cookbook/read-word-document/)
- [Read an Excel file](https://recursiveai.org/onedocument/cookbook/read-excel-file/)

---

## The short answer

Create a `RedactionPlan`, add a literal or pattern match, then call `doc.Redact(plan, outputPath)`. OneDocument writes a new document and searches the written package for the removed content. Check the returned report, including `Verified`, `Survivors` and `Gaps`, before releasing the output. The source file is not changed.

The [redaction documentation](https://recursiveai.org/onedocument/docs/redaction/) defines the matching rules and the report. The example on this page replaces the exact string “Jane Doe” in a generated DOCX. It does not identify personal information automatically or decide which information you are allowed to disclose.

## Is it possible to redact a Word document?

Yes, for content covered by the redaction plan. The matcher joins runs within each paragraph, so a name split by bold formatting can still match as a single phrase. It also searches other package locations, including comments, notes, headers, footers, properties and hyperlink targets. This is broader than replacing only the visible body text.

Exact characters matter. A normal space is not a nonbreaking space, and a straight apostrophe is not a typographic apostrophe. The variation uses a pattern to accept either kind of space between the two name components. Matches do not span paragraphs or different parts. List the relevant variants or choose a suitably specific pattern for the document’s actual data.

The output path must differ from the source path. Older formats are staged through the document model into OOXML, so redacting a binary DOC is not an in-place binary edit. The report records whether conversion occurred and the output format. Keep the original under its existing access controls, and distribute only the reviewed output.

## How do I black out text in a Word document?

The default redaction mark is `█`, repeated once per removed character. The first touched run keeps its formatting and receives the mark; matched characters in later runs are cut. The example therefore prints eight block characters for “Jane Doe”. The result is replacement content, not a floating black rectangle layered over an unchanged name.

This operation does not perform optical character recognition. A name inside a picture’s pixels is not matched as document text. Pictures need a region-based removal decision. Derived content can also require review: a table of contents, cross-reference result or document-property count may reflect removed content without containing the literal secret. The report exposes documented gaps rather than silently treating them as solved.

## Is putting black over text the same as redacting it?

No. Covering a name changes the view; redaction must remove the underlying content. [Loughborough University’s guidance](https://www.lboro.ac.uk/data-privacy/help/redact/) defines redaction as permanently deleting or making confidential information inaccessible. Its manual workflow uses PDF, whereas this recipe produces another editable Word document.

A successful `Verified` result is the library’s check of the written package against your matches, not an independent audit or a judgment that the document is safe to publish. Binary embedded content, pictures and Unicode variants need particular care. Review the gaps and survivors, inspect the result, and apply a disclosure review appropriate to the sensitivity of the file. Black marks alone are not that review.