Compress PDF Files in C#

PDF documents are widely used in various fields, such as education, business, and government. However, PDF files can be very large, which can cause problems when sharing or storing them. To solve this problem, compressing PDF documents has become a common practice. In this article, we will explore how to programmatically compress a PDF document using a .NET PDF library.

Installation

To get started, we'll need to download the library Spire.PDF for .NET via the below link or install it directly via Nuget.
https://www.e-iceblue.com/Download/download-pdf-for-net-now.html

Compress PDF Documents Using C#

Two main factors that affect the size of a PDF document are fonts and high-quality images. To reduce the file size, we can compress the font resources and the image quality.

Sample C# Code:

using Spire.Pdf;
using Spire.Pdf.Conversion.Compression;

namespace CompressPdf
{
    class Program
    {
        static void Main(string[] args)
        {
            //Load a PDF document while initializing the PdfCompressor object
            PdfCompressor compressor = new PdfCompressor("Island.pdf");

            //Get text compression options
            TextCompressionOptions textCompression = compressor.Options.TextCompressionOptions;

            //Compress fonts
            textCompression.CompressFonts = true;

            //Unembed fonts
            //textCompression.UnembedFonts = true;

            //Get image compression options
            ImageCompressionOptions imageCompression = compressor.Options.ImageCompressionOptions;

            //Set the compressed image quality
            imageCompression.ImageQuality = ImageQuality.High;

            //Resize images
            imageCompression.ResizeImages = true;

            //Compress images
            imageCompression.CompressImage = true;

            //Save the compressed document to file
            compressor.CompressToFile("Compressed.pdf");
        }
    }
}

Other Features Provided by the .NET PDF API.

In addition to compressing PDF documents, Spire.PDF for .NET provides many other features that can help developers manipulate PDF documents. Here are some of the key features:

• Create PDF documents from scratch in C#/VB.NET

• Convert HTML or Images to PDF in C#/VB.NET

• Merge or split PDF documents in C#/VB.NET

• Extract text or images from PDF in C#/VB.NET

• Encrypt or decrypt PDF documents in C#/VB.NET

• Print PDF documents in C#/VB.NET