Compare Word Documents in Node.js Leave feedback

Note

💡For the complete working code and detailed explanations, please refer to the full repository here.
This repository contains all source files, helper classes, and configuration examples to implement Word document comparison in your Node.js applications.

This article demonstrates how to compare Word documents (DOCX) using GroupDocs.Comparison for Node.js via Java.
The sample project provides ready-to-use examples that enable developers to quickly identify document differences with customizable styling, password protection support, and stream-based processing.

Word document comparison is essential for legal document review, contract versioning, compliance auditing, and document version control.
With GroupDocs.Comparison for Node.js via Java, you can automate document comparison workflows and generate result documents that highlight insertions, deletions, and modifications with configurable visual styles.

💡 Use this approach when you need to automatically detect and highlight differences between Word document versions without manual review.

Before proceeding, make sure you have:

• GroupDocs.Comparison for Node.js via Java installed. Get a free trial.
• Node.js >=20.0.0 installed.
• Java Runtime / JDK 8+ (Java 17 recommended).
• JAVA_HOME environment variable configured.

Clone or download the sample repository.

git clone https://github.com/groupdocs-comparison/nodejs-compare-word-documents-sample.git
cd nodejs-compare-word-documents-sample

Install dependencies with npm:

npm install

The project includes:

nodejs-compare-word-documents-sample/
 ├── src/
 │   ├── compareWordDocuments.js      # Core comparison functions
 │   ├── examples/
 │   │   ├── basicComparison.js       # Basic comparison example
 │   │   ├── advancedComparison.js    # Advanced styling example
 │   │   ├── passwordProtectedComparison.js  # Password-protected comparison
 │   │   └── streamComparison.js      # Stream-based comparison
 │   └── utils/
 │       ├── fileHelper.js            # File utilities
 │       ├── licenseHelper.js         # License management
 │       └── constants.js             # Configuration constants
 ├── sample-files/                    # Input Word documents
 ├── package.json
 └── README.md

Below is a simplified version of the sample code. For the full implementation, see the repository.

compareWordDocuments.js provides the core function for comparing Word documents:

const { compareWordDocuments } = require('./src/compareWordDocuments');

// Compare two Word documents
await compareWordDocuments(
  'sample-files/source.docx',
  'sample-files/target.docx',
  'output/result.docx'
);

compareWordDocuments.js also includes a function for custom styling:

const { compareWordDocumentsWithStyles } = require('./src/compareWordDocuments');
const java = require('java');
const Color = java.import('java.awt.Color');

// Configure custom styles
const styleConfig = {
  inserted: {
    highlightColor: Color.BLUE,
    fontColor: Color.BLUE,
    bold: true,
    underline: true
  },
  deleted: {
    highlightColor: Color.RED,
    fontColor: Color.RED,
    bold: true,
    strikethrough: true
  },
  changed: {
    highlightColor: Color.GREEN,
    fontColor: Color.GREEN,
    bold: true,
    underline: true
  },
  generateSummaryPage: true
};

await compareWordDocumentsWithStyles(
  'sample-files/source.docx',
  'sample-files/target.docx',
  'output/result_styled.docx',
  styleConfig
);

passwordProtectedComparison.js demonstrates handling encrypted documents:

const { compareWordDocuments } = require('./src/compareWordDocuments');

await compareWordDocuments(
  'sample-files/source_protected.docx',
  'sample-files/target_protected.docx',
  'output/result_protected.docx',
  {
    loadOptions: {
      sourcePassword: 'source_password_123',
      targetPassword: 'target_password_123'
    }
  }
);

streamComparison.js shows how to compare documents using Java input streams:

const groupdocs = require('@groupdocs/groupdocs.comparison');
const java = require('java');
const FileInputStream = java.import('java.io.FileInputStream');

const sourceInputStream = new FileInputStream('sample-files/source.docx');
const targetInputStream = new FileInputStream('sample-files/target.docx');

const comparer = new groupdocs.Comparer(sourceInputStream);
comparer.add(targetInputStream);

await comparer.compare('output/result_stream.docx');

sourceInputStream.close();
targetInputStream.close();

• Replace file paths with your actual document locations.
• Default styling uses blue for inserted content, red for deleted content, and green for modified content.
• Summary page generation provides a consolidated view of all changes in a single page.
• Stream-based comparison is useful when documents are loaded from memory or network sources.
• For detailed examples and advanced scenarios, see the full repository.

• Compare Documents
• Customize Changes Styles
• Load Password-Protected Documents
• Legal Document Comparison API: Automate Contract Review with Node.js
• Optimize Document Comparison Performance: Scale to Millions of Files with Node.js