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Compare PDF Documents in C#

Wordize for .NET is a professional solution for programmatic PDF file comparison and difference detection. The Comparer class enables C# developers to identify content differences between two PDF 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 PDF 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 PDF 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 PDF 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:
  • Version tracking between different PDF file versions in document management systems
  • Contract and agreement analysis for identifying critical changes in PDF documents with character-level precision
  • Legal document review - comparing official PDF documents to detect unauthorized modifications
  • Technical documentation quality control - verifying PDF specifications against reference versions
  • Financial report auditing - comparing PDF report versions to identify discrepancies and errors
  • Translation validation - comparing original and translated PDF documents for quality control

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

C#
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Upload the first document
Upload the second document
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using Wordize.Comparing;

Comparer.Compare("Input1.pdf", "Input2.pdf",
    "Output.pdf", "Author Name", DateTime.Now);
using Wordize.Comparing; Comparer.Compare("Input1.pdf", "Input2.pdf", "Output.pdf", "Author Name", DateTime.Now); using Wordize.Comparing; using Wordize.Saving; var imageStreams = Comparer.CompareToImages("Input1.pdf", "Input2.pdf", new ImageSaveOptions(SaveFormat.Pdf), "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}.pdf"); stream.CopyTo(file); }
Run code

How to Compare PDF in C#

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