Replace Text in PDF with C#

Wordize for .NET is an efficient solution for text replacement in PDF documents. The Replacer class enables C# developers to programmatically replace text fragments in PDF files using both simple strings and regular expressions.

Key Features:

Simple find and replace text - the Replacer.Replace() method performs text replacement throughout all parts of PDF documents while preserving formatting
Regex support for complex text transformations, including text replacement using capture groups
Flexible search options - the FindReplaceOptions class controls search parameters, including case sensitivity, whole word matching, ignoring text in various document elements, and more
Substitutions in replacement text - use UseSubstitutions for special replacement patterns: found text, text before match, text after match
Formatted replacement - support for specialized markup in replacement text through ReplacementFormat
Export results to image format - the ReplaceToImages() method returns results as an array of images
Fluent API support for find and replace text operations through ReplacerContext and method chaining, adding clarity to your C# code

Use Cases:

Standardize PDF document styling
Validate information in PDF documents
Replace placeholder fields with actual data
Remove or mask personal data

Test the capabilities of programmatic PDF text replacement in the interactive online demo presented on this page. Simply upload your PDF document, specify the search text and replacement text, run the operation, and download the updated file for verification. The provided C# code snippet is ready for use in your .NET project.

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Select output format from the list

 
				
				
		
using Wordize.Replacing;

Replacer.Replace("Input.pdf", "Output.pdf", "Text or Regex", "Text or Regex");
										using Wordize.Replacing;

Replacer.Replace("Input.pdf", "Output.pdf", "Text or Regex", "Text or Regex");
										using Wordize.Replacing;
using Wordize.Saving;

var imageStreams = Replacer.ReplaceToImages("Input.pdf", 
    new ImageSaveOptions(SaveFormat.Pdf), "Text or Regex", "Text or Regex");

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);
}
					
using Wordize.Replacing;

FindReplaceOptions options = new FindReplaceOptions() { UseSubstitutions = true };
Replacer.Replace("Input.pdf", "Output.pdf", new Regex(@"Text or Regex"), "Text or Regex", options);
										using Wordize.Replacing;

FindReplaceOptions options = new FindReplaceOptions() { UseSubstitutions = true };
Replacer.Replace("Input.pdf", "Output.pdf", new Regex(@"Text or Regex"), "Text or Regex", options);
										using Wordize.Replacing;
using Wordize.Saving;

FindReplaceOptions options = new FindReplaceOptions() { UseSubstitutions = true };
var imageStreams = Replacer.ReplaceToImages("Input.pdf", 
    new ImageSaveOptions(SaveFormat.Pdf), new Regex(@"Text or Regex"), "Text or Regex", options);

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 Replace Text in PDF with C#

Add Wordize SDK to your .NET project
Call the Replacer.Replace() method, specifying the PDF document, search text, replacement text, and search parameters
Get the PDF document with replaced text