Compare HTML Documents in C#

Wordize for .NET is an effective solution for programmatic HTML file comparison and difference detection. The Comparer class enables C# developers to identify content differences between two HTML documents with the required level of detail and save comparison results to an output document. Differences between documents are displayed as revisions of the first HTML document with author and modification time information.

Key Features:

Precise difference detection - the Comparer.Compare() method creates a result document with identified changes, including insertions, deletions, and modifications
Flexible HTML comparison settings via the CompareOptions class: granular change tracking (by characters or words), text movement detection, case change ignoring, table exclusion, document fields, footnotes and endnotes, comments, text boxes, formatting, headers and footers
Image format export capability - the Comparer.CompareToImages() method returns HTML comparison results as an array of images
Support for both file and Stream object operations
Fluent API support for comparison operations through Comparer.ComparerContext and method chaining, enhancing C# code clarity

Use Cases:

HTML document version control - tracking changes between different HTML file versions in document management systems
Legal document review - analyzing contract and agreement changes for critical HTML modifications with character-level precision
Content auditing - comparing HTML files against reference versions for quality control and standards compliance
Collaborative development - analyzing HTML document changes from different team members for coordinated workflow
Translation validation - comparing original and translated HTML versions for localization quality control and source text compliance
Archive comparison - comparing HTML documents from different time periods for content evolution analysis and historical change identification

Test the capabilities of programmatic HTML document comparison in the interactive online demo presented on this page. Simply upload two HTML files, run the comparison operation, and download results with identified differences. The provided C# code snippet is ready for use in your .NET project.

Run code

Upload the first document

Upload the second document

Select output format from the list

using Wordize.Comparing;

Comparer.Compare("Input1.html", "Input2.html",
    "Output.html", "Author Name", DateTime.Now);

                            using Wordize.Comparing;

Comparer.Compare("Input1.html", "Input2.html",
    "Output.html", "Author Name", DateTime.Now);

                            using Wordize.Comparing;
using Wordize.Saving;

var imageStreams = Comparer.CompareToImages("Input1.html", "Input2.html", 
    new ImageSaveOptions(SaveFormat.Html), "Author Name", DateTime.Now);

foreach (var (stream, page) in imageStreams.Select((s, i) => (s, i)))
{
    using var _ = stream;
    stream.Position = 0;
    
    using var file = File.Create($"Output_{page + 1}.html");
    stream.CopyTo(file);
}
            

                        Run code
			    

How to Compare HTML in C#

Connect the Wordize SDK to your .NET project
Call the Comparer.Compare() method, specifying two HTML documents, a result file for saving the comparison output, and metadata (author and date) as arguments
Get the HTML document comparison results