A powerful Typescript, Python and .NET library for manipulating Open XML documents (DOCX, XLSX, PPTX).

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Docxodus is a fork of Open-Xml-PowerTools upgraded to .NET 10.0. It provides tools for comparing Word documents, converting between DOCX and HTML, projecting DOCX to anchor-addressed markdown for LLM pipelines, programmatically editing DOCX content via a stateful session API, merging documents, and more.

Quick Start

Install the Library

# Install from NuGet
dotnet add package Docxodus

Using as a Library

using Docxodus;

// Compare documents
var original = new WmlDocument("original.docx");
var modified = new WmlDocument("modified.docx");

var settings = new WmlComparerSettings
{
    AuthorForRevisions = "Redline",
    DetailThreshold = 0
};

var result = WmlComparer.Compare(original, modified, settings);

// Get list of revisions (with move detection)
var revisions = WmlComparer.GetRevisions(result, settings);
foreach (var rev in revisions)
{
    if (rev.RevisionType == WmlComparer.WmlComparerRevisionType.Moved)
        Console.WriteLine($"Moved (group {rev.MoveGroupId}): {rev.Text}");
    else
        Console.WriteLine($"{rev.RevisionType}: {rev.Text}");
}

// Save the redlined document
result.SaveAs("redline.docx");

CLI Tools

Docxodus includes two command-line tools:

Redline (Document Comparison)

# Install globally
dotnet tool install -g Redline

# Usage
redline original.docx modified.docx output.docx

# With custom author tag
redline original.docx modified.docx output.docx --author="Legal Review"

Option	Description
--author=<name>	Author name for tracked changes (default: "Redline")
-h, --help	Show help message
-v, --version	Show version information

docx2html (HTML Conversion)

# Install globally
dotnet tool install -g Docx2Html

# Basic conversion
docx2html document.docx

# Specify output file
docx2html document.docx output.html

# Extract images to files instead of embedding as base64
docx2html document.docx --extract-images

# Use inline styles instead of CSS classes
docx2html document.docx --inline-styles

Option	Description
--title=<text>	Page title (default: document title or filename)
--css-prefix=<text>	CSS class prefix (default: "pt-")
--inline-styles	Use inline styles instead of CSS classes
--extract-images	Save images to separate files instead of embedding
-h, --help	Show help message
-v, --version	Show version information

Download Standalone Binaries

Pre-built binaries are available on the Releases page:

redline (Document Comparison):

Platform	Download
Windows (x64)	redline-win-x64.exe
Linux (x64)	redline-linux-x64
macOS (x64)	redline-osx-x64
macOS (ARM)	redline-osx-arm64

docx2html (HTML Conversion):

Platform	Download
Windows (x64)	docx2html-win-x64.exe
Linux (x64)	docx2html-linux-x64
macOS (x64)	docx2html-osx-x64
macOS (ARM)	docx2html-osx-arm64

Build from Source

# Clone the repository
git clone https://github.com/JSv4/Docxodus.git
cd Docxodus

# Build
dotnet build Docxodus.sln

# Run the CLI
dotnet run --project tools/redline/redline.csproj -- --help

Testing

.NET Unit Tests

# Run all tests (~1,100 tests)
dotnet test Docxodus.Tests/Docxodus.Tests.csproj

# Run specific test by name
dotnet test --filter "FullyQualifiedName~WC001"

# Run tests for a specific class
dotnet test --filter "FullyQualifiedName~WmlComparerTests"

npm/WASM Browser Tests (Playwright)

# Need to be in npm subdirectory
cd npm

# Install dependencies (first time only)
npm install
npx playwright install chromium

# Build WASM and TypeScript (required before tests)
npm run build

# Run all Playwright tests (~62 tests)
npm test

# Run specific test by name pattern
npx playwright test --grep "Document Structure"

# Run tests with browser visible
npx playwright test --headed

# TypeScript type checking
npx tsc --noEmit

Features

• WmlComparer - Compare two DOCX files and generate redlines with tracked changes
  • Move Detection - Automatically detects when content is relocated (not just deleted and re-inserted)
  • Format Change Detection - Detects formatting-only changes (bold, italic, font size, etc.)
  • Configurable similarity threshold and minimum word count
  • Links move pairs via MoveGroupId for easy tracking
• WmlToHtmlConverter / HtmlToWmlConverter - Bidirectional DOCX ↔ HTML conversion
  • Comment rendering (endnote-style, inline, or margin)
  • Paginated output mode for PDF-like viewing
  • Headers, footers, footnotes, and endnotes support
  • Custom annotation rendering
• WmlToMarkdownConverter - Anchor-addressed markdown projection of a DOCX with stable per-block IDs - a text view suitable for LLM editing pipelines, structured search indexers, and diff/review UIs
• DocxSession - Stateful in-memory DOCX editor keyed by markdown-projection anchor ids - the write-side counterpart to WmlToMarkdownConverter for agentic editing pipelines
  • Text and structural edits: replace paragraph text, delete blocks, insert/split/merge paragraphs, change paragraph style, adjust list level, replace table-cell content
  • Character-range formatting (bold, italic, underline, strike, code, color, run style) addressed by substring, span, or a prior search match
  • Surgical text replacement that preserves per-run formatting on either side of the rewritten slice - including a span-addressed variant that lets identical placeholders in one paragraph each receive distinct values
  • Cross-run text search with per-fragment run breakdown (Grep), plus a cross-block variant (GrepCrossBlock) that lets a single match span adjacent paragraphs, headings, and list items
  • Template-slot enumeration that classifies bracketed regions as value blanks, alternative clauses, or drafter hints
  • Anchor discovery by text, regex, kind, bookmark, annotation id, or shared label - so an agent told to "edit the indemnification clause" can resolve intent to anchors without re-walking the document
  • NBSP / smart-quote handling so common Word whitespace and punctuation don't sabotage literal find/replace
  • Tracked-change mode that lands every mutation as w:ins / w:del instead of accepted edits
  • Bounded snapshot undo/redo
  • Raw OOXML escape hatch for content the markdown subset can't express (charts, equations, content controls)
  • Typed result envelope on every call - no exceptions across the API boundary
  • Available in .NET, WASM, and an npm TypeScript wrapper
• DocumentBuilder - Merge and split DOCX files
• DocumentAssembler - Template population from XML data
• PresentationBuilder - Merge and split PPTX files
• SpreadsheetWriter - Simplified XLSX creation API
• OpenXmlRegex - Search/replace in DOCX/PPTX using regular expressions
• OpenContractExporter - Export documents to OpenContracts format for NLP/document analysis
• Supporting utilities for document manipulation

Browser/JavaScript Usage (npm)

Docxodus is also available as an npm package for client-side usage via WebAssembly:

npm install docxodus

import {
  initialize,
  convertDocxToHtml,
  compareDocuments,
  getRevisions,
  getDocumentMetadata,
  isMove,
  isMoveSource,
  isFormatChange,
  findMovePair,
  CommentRenderMode,
  PaginationMode
} from 'docxodus';

await initialize();

// Convert DOCX to HTML with comments and pagination
const html = await convertDocxToHtml(docxFile, {
  commentRenderMode: CommentRenderMode.EndnoteStyle,
  paginationMode: PaginationMode.Paginated,
  renderHeadersAndFooters: true
});

// Compare two documents
const redlinedDocx = await compareDocuments(originalFile, modifiedFile);

// Get revisions with move and format change detection
const revisions = await getRevisions(redlinedDocx);
for (const rev of revisions) {
  if (isMove(rev)) {
    const pair = findMovePair(rev, revisions);
    if (isMoveSource(rev)) {
      console.log(`Content moved from: "${rev.text}" to: "${pair?.text}"`);
    }
  } else if (isFormatChange(rev)) {
    console.log(`Format changed: ${rev.formatChange?.changedPropertyNames?.join(', ')}`);
  }
}

// Get document metadata for lazy loading
const metadata = await getDocumentMetadata(docxFile);
console.log(`${metadata.totalParagraphs} paragraphs, ${metadata.estimatedPageCount} pages`);

See the npm package documentation for full API reference, React hooks, and usage examples.

Requirements

• .NET 10.0 or later

License

MIT License - see LICENSE for details.

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Built on the shoulders of Open-Xml-PowerTools. Thanks to Eric White, Thomas Barnekow, and all original contributors.