.NET comparison APIs - Compare files for changes

A difference checker solution for two same format documents within any of your .NET application that targets Windows Forms, ASP.NET, WPF or WCF Services

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.NET document comparison API

GroupDocs.Comparison for .NET


GroupDocs.Comparison for .NET – An API to compare and merge Microsoft Word, Excel, PowerPoint, openDocument ODT, PDF, Text and HTML documents.

Document comparison API compares content to detect changes for words, paragraphs and characters. It also compares style changes like font size, bold, italic etc. Differences summary saved in a separate result file

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Advanced Document Comparison API Features



Multiple file formats supported


Beat Performance - Accurate and fastest comparison API


Annotation Comparison


Easy integration with just two lines of code to perform document comparison


Free ASP.NET MVC application with integrated file comparison API


Compares content for differences in words and paragraphs


Get differences for styles like font size, bold, italic etc


Separate differences summary

Compare documents - the easy way

It is now easy to review and compare documents for keeping track of changes with just few lines of code

Document comparison - C#

 //Source and target files to be compared
string source = @"source.docx";
string target = @"target.docx";
Comparer comparer = new Comparer();
//Compare two documents
ICompareResult result = comparer.Compare(source, target, new ComparisonSettings());

Microsoft Word Files Comparison

  • Native track changes for Microsoft word files comparison
  • Merge these track changes and save in separate file
  • Accept/reject changes in Word files
  • Support for Group Shapes while using Comparison.Words
  • Implement Comparison by Page Numbers while using Comparison.Words
  • Implement formulas comparison
  • Merge & compare up to 3 Word files

HTML Files Comparison

  • Save HTML files to word document while using Comparison.Text
  • Can save comparison result as images

PDF Comparison

Implement the own absorber of tables

Automatic format detection with saving results into

  • File
  • File with extension
  • File with extension for encrypted documents
  • File for encrypted documents
  • File with comparison type and settings for encrypted documents
  • Stream
  • Stream with comparison settings
  • Stream with comparison type and settings
  • Stream for encrypted documents
  • Stream with comparison settings for encrypted documents
  • Stream with comparison type and settings for encrypted documents

Compare Files API Supported Formats

Following documents types can be compared

  • Portable Document Format
  • Microsoft Word Formats
  • Microsoft Excel Formats
  • Microsoft PowerPoint Formats
  • OpenDocument Formats
  • Plain Text Files
  • HTML

Support and Learning Resources


GroupDocs.Comparison offers document automation APIs for other popular development environments as listed below: