Text aus PDF in C# mit iTextSharp extrahieren vs IronPDF

Extract Text from PDF Files with IronPDF

Once installed, extracting text is straightforward:

using IronPdf;

// Load the PDF document
var pdf = PdfDocument.FromFile("invoice.pdf");

// Extract text from the PDF
string extractedText = pdf.ExtractAllText();

// Output the extracted text
Console.WriteLine(extractedText);

using IronPdf;

// Load the PDF document
var pdf = PdfDocument.FromFile("invoice.pdf");

// Extract text from the PDF
string extractedText = pdf.ExtractAllText();

// Output the extracted text
Console.WriteLine(extractedText);

Imports IronPdf

' Load the PDF document
Private pdf = PdfDocument.FromFile("invoice.pdf")

' Extract text from the PDF
Private extractedText As String = pdf.ExtractAllText()

' Output the extracted text
Console.WriteLine(extractedText)

Note: This method reads the entire PDF file and returns the text in reading order, saving hours of parsing time compared to traditional libraries.

No need to handle encodings, content streams, or manual parsing. IronPDF handles all of that internally, providing clean and accurate output with minimal setup. You could then easily save the extracted text to a new text file for further manipulation or use.

Extract Text from PDF documents with iTextSharp

Here’s a sample to extract text from a single PDF page:

using iText.Kernel.Pdf;
using iText.Kernel.Pdf.Canvas.Parser;
using iText.Kernel.Pdf.Canvas.Parser.Listener;

// Define the path to your PDF
string path = "sample.pdf";

// Open the PDF reader and document
using (PdfReader reader = new PdfReader(path))
using (PdfDocument pdf = new PdfDocument(reader))
{
    // Use a simple text extraction strategy
    var strategy = new SimpleTextExtractionStrategy();

    // Extract text from the first page
    string pageText = PdfTextExtractor.GetTextFromPage(pdf.GetPage(1), strategy);

    // Output the extracted text
    Console.WriteLine(pageText);
}

using iText.Kernel.Pdf;
using iText.Kernel.Pdf.Canvas.Parser;
using iText.Kernel.Pdf.Canvas.Parser.Listener;

// Define the path to your PDF
string path = "sample.pdf";

// Open the PDF reader and document
using (PdfReader reader = new PdfReader(path))
using (PdfDocument pdf = new PdfDocument(reader))
{
    // Use a simple text extraction strategy
    var strategy = new SimpleTextExtractionStrategy();

    // Extract text from the first page
    string pageText = PdfTextExtractor.GetTextFromPage(pdf.GetPage(1), strategy);

    // Output the extracted text
    Console.WriteLine(pageText);
}

Imports iText.Kernel.Pdf
Imports iText.Kernel.Pdf.Canvas.Parser
Imports iText.Kernel.Pdf.Canvas.Parser.Listener

' Define the path to your PDF
Private path As String = "sample.pdf"

' Open the PDF reader and document
Using reader As New PdfReader(path)
Using pdf As New PdfDocument(reader)
	' Use a simple text extraction strategy
	Dim strategy = New SimpleTextExtractionStrategy()

	' Extract text from the first page
	Dim pageText As String = PdfTextExtractor.GetTextFromPage(pdf.GetPage(1), strategy)

	' Output the extracted text
	Console.WriteLine(pageText)
End Using
End Using

This example demonstrates iTextSharp’s capability, but notice the verbosity and additional objects required to perform a simple task.

Advanced Example: Extracting Text from a Page Range with IronPDF

IronPDF supports granular control over page selection and layout-aware text extraction.

using IronPdf;

// Load the PDF document
var pdf = PdfDocument.FromFile("longPdf.pdf");

// Define the page numbers to extract text from
int[] pages = new[] { 2, 3, 4 };

// Extract text from the specified pages
var text = pdf.ExtractTextFromPages(pages);

// Output the extracted text
Console.WriteLine("Extracted text from pages 2, 3, and 4:\n" + text);

using IronPdf;

// Load the PDF document
var pdf = PdfDocument.FromFile("longPdf.pdf");

// Define the page numbers to extract text from
int[] pages = new[] { 2, 3, 4 };

// Extract text from the specified pages
var text = pdf.ExtractTextFromPages(pages);

// Output the extracted text
Console.WriteLine("Extracted text from pages 2, 3, and 4:\n" + text);

Imports Microsoft.VisualBasic
Imports IronPdf

' Load the PDF document
Private pdf = PdfDocument.FromFile("longPdf.pdf")

' Define the page numbers to extract text from
Private pages() As Integer = { 2, 3, 4 }

' Extract text from the specified pages
Private text = pdf.ExtractTextFromPages(pages)

' Output the extracted text
Console.WriteLine("Extracted text from pages 2, 3, and 4:" & vbLf & text)

Advanced Example: Extracting Text from a Page Range using iTextSharp

In iTextSharp, you’ll need to manually specify the page range and extract text using PdfTextExtractor:

using iTextSharp.text.pdf;
using iTextSharp.text.pdf.parser;
using System.IO;
using System.Text;

// Load the PDF document
PdfReader reader = new PdfReader("longPdf.pdf");
StringBuilder textBuilder = new StringBuilder();

// Extract text from pages 2–4
for (int i = 2; i <= 4; i++)
{
    string pageText = PdfTextExtractor.GetTextFromPage(reader, i, new LocationTextExtractionStrategy());
    textBuilder.AppendLine(pageText);
}

// Output the extracted text
Console.WriteLine(textBuilder.ToString());

// Close the PDF reader
reader.Close();

using iTextSharp.text.pdf;
using iTextSharp.text.pdf.parser;
using System.IO;
using System.Text;

// Load the PDF document
PdfReader reader = new PdfReader("longPdf.pdf");
StringBuilder textBuilder = new StringBuilder();

// Extract text from pages 2–4
for (int i = 2; i <= 4; i++)
{
    string pageText = PdfTextExtractor.GetTextFromPage(reader, i, new LocationTextExtractionStrategy());
    textBuilder.AppendLine(pageText);
}

// Output the extracted text
Console.WriteLine(textBuilder.ToString());

// Close the PDF reader
reader.Close();

Imports iTextSharp.text.pdf
Imports iTextSharp.text.pdf.parser
Imports System.IO
Imports System.Text

' Load the PDF document
Private reader As New PdfReader("longPdf.pdf")
Private textBuilder As New StringBuilder()

' Extract text from pages 2–4
For i As Integer = 2 To 4
	Dim pageText As String = PdfTextExtractor.GetTextFromPage(reader, i, New LocationTextExtractionStrategy())
	textBuilder.AppendLine(pageText)
Next i

' Output the extracted text
Console.WriteLine(textBuilder.ToString())

' Close the PDF reader
reader.Close()

Code Comparison Summary

Both IronPDF and iTextSharp are capable of advanced PDF text extraction, but their approaches differ significantly in complexity and clarity:

• IronPDF keeps things clean and accessible. Its high-level methods like PdfDocument.ExtractAllText() allow you to extract structured content with minimal setup. The code is straightforward, making it easy to implement even for developers new to PDF processing.

• iTextSharp, on the other hand, requires a deeper understanding of the PDF structure. Extracting text involves setting up custom render listeners, managing pages manually, and interpreting layout data line by line. While powerful, it’s more verbose and less intuitive, making IronPDF a faster and more maintainable option for most .NET projects.

But our comparison doesn't end here. Next, let's look at how these two libraries compare in other areas.

1. Ease of Use

IronPDF: Clean and Modern API

IronPDF emphasizes developer experience. Installation is easy via NuGet, and the syntax is intuitive:

using IronPdf;

// Load the PDF
var pdf = PdfDocument.FromFile("sample.pdf");

// Extract all text from every page
string extractedText = pdf.ExtractAllText();

// Output the extracted text
Console.WriteLine(extractedText);

using IronPdf;

// Load the PDF
var pdf = PdfDocument.FromFile("sample.pdf");

// Extract all text from every page
string extractedText = pdf.ExtractAllText();

// Output the extracted text
Console.WriteLine(extractedText);

Imports IronPdf

' Load the PDF
Private pdf = PdfDocument.FromFile("sample.pdf")

' Extract all text from every page
Private extractedText As String = pdf.ExtractAllText()

' Output the extracted text
Console.WriteLine(extractedText)

IronPDF abstracts the complexity behind simple method calls like ExtractAllText(), requiring no boilerplate or parsing logic.

iTextSharp: More Verbose and Lower-Level

iTextSharp requires manual parsing of each page and more effort to extract plain text.

using iTextSharp.text.pdf;
using iTextSharp.text.pdf.parser;
using System.IO;
using System.Text;

// Load the PDF
var reader = new PdfReader("sample.pdf");
StringBuilder text = new StringBuilder();

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

// Output the extracted text
Console.WriteLine(text.ToString());

using iTextSharp.text.pdf;
using iTextSharp.text.pdf.parser;
using System.IO;
using System.Text;

// Load the PDF
var reader = new PdfReader("sample.pdf");
StringBuilder text = new StringBuilder();

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

// Output the extracted text
Console.WriteLine(text.ToString());

Imports iTextSharp.text.pdf
Imports iTextSharp.text.pdf.parser
Imports System.IO
Imports System.Text

' Load the PDF
Private reader = New PdfReader("sample.pdf")
Private text As New StringBuilder()

For i As Integer = 1 To reader.NumberOfPages
	text.Append(PdfTextExtractor.GetTextFromPage(reader, i))
Next i

' Output the extracted text
Console.WriteLine(text.ToString())

Developers need to manually loop through pages, which introduces more code and potential for bugs if edge cases arise.

2. Performance and Reliability

• IronPDF is built on a modern rendering engine (Chromium), making it well-suited for modern PDFs, even those with embedded fonts, rotated text, and multiple layouts. Text extraction is layout-aware and preserves spacing more naturally.

• iTextSharp, although powerful, may struggle with complex formatting. PDF files with mixed orientation or non-standard encodings may yield garbled or improperly ordered text.

3. Cost and Licensing

4. Developer Support and Documentation

• IronPDF: Comes with modern documentation, video tutorials, and fast ticket-based support.

• iTextSharp: Good documentation, but limited free support unless you're a paid customer.

5. Cross-Library Summary