How to compare two pdf in c#?

You can perform following steps:

• Install Nuget Package 'iTextsharp'
  

  Install-Package iTextSharp

• Once you have installed the above Nuget package, extract text from the both PDF files
  

   var ExtractedPDFToString = ExtractTextFromPdf(@"C:\Users\CT\Desktop\pdf-sample.pdf");?

• Where ExtractTextFromPDF function is as below or check "read pdf file in C#"

   public static string ExtractTextFromPdf(string path)
          {
              using (PdfReader reader = new PdfReader(path))
              {
                  StringBuilder text = new StringBuilder();
  
                  for (int i = 1; i <= reader.NumberOfPages; i++)
                  {
                      text.Append(PdfTextExtractor.GetTextFromPage(reader, i));
                  }
  
                  return text.ToString();
              }
          }

• Once you have text from both the PDF files you can compare the text using C# and get difference
  

              var ExtractedPDFToString1= ExtractTextFromPdf(@"E:\samplepdf\sample1.pdf");
              var ExtractedPDFToString2 = ExtractTextFromPdf(@"E:\samplepdf\sample2.pdf");
  
              IEnumerable<string> onlyB = ExtractedPDFToString2.Except(ExtractedPDFToString1).ToList();
  
              foreach(var lin in onlyB)
              {
                  Console.WriteLine(lin); //difference line by line
              }?

Complete code

using iTextSharp.text.pdf;
using iTextSharp.text.pdf.parser;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ReadFromPDF
{
    class Program
    {
        static void Main(string[] args)
        {

            var ExtractedPDFToString1= ExtractTextFromPdf(@"E:\samplepdf\sample1.pdf");
            var ExtractedPDFToString2 = ExtractTextFromPdf(@"E:\samplepdf\sample2.pdf");

            IEnumerable<string> onlyB = ExtractedPDFToString2.Except(ExtractedPDFToString1).ToList();

            foreach(var lin in onlyB)
            {
                Console.WriteLine(lin); //difference line by line
            }
        }


        public static string[] ExtractTextFromPdf(string path)
        {
            using (PdfReader reader = new PdfReader(path))
            {
                StringBuilder text = new StringBuilder();

                for (int i = 1; i <= reader.NumberOfPages; i++)
                {
                    text.Append(PdfTextExtractor.GetTextFromPage(reader, i));
                }

                return text.ToString().Split(new[] { '\r', '\n' });
            }
        }
    }
}

Output:

Above image shows both pdf1/pdf 2 and difference in console as output