7 Ways to Compress PDF Files in C#, VB.NET

TL;DR: Want to shrink large PDFs in your C# or VB.NET applications? Discover 7 effective techniques using Syncfusion Essential PDF to optimize file size for better storage, transmission, and processing!

PDF files may contain many images. Removing the images from a PDF file is usually not an option since they are necessary for many PDFs. Downsampling the images will decrease the number of pixels and is possibly the most effective way to reduce PDF file size. The user can control the PDF file size with respect to the quality of the image.

//Create a new compression option object.
PdfCompressionOptions options = new PdfCompressionOptions();
options.CompressImages = true;
//Image quality is a percentage.
options.ImageQuality = 10;

Reducing PDF file size by optimizing fonts

Boost your productivity with Syncfusion's PDF Library! Gain access to invaluable insights and tutorials in our extensive documentation.

Read Now

Reducing PDF file size by removing metadata

Sometimes unnecessary metadata might be present in the PDF file. Remove the unnecessary metadata, to reduce the size of the PDF.

PdfCompressionOptions options = new PdfCompressionOptions();
options.RemoveMetadata = true;

Optimizing the page contents will remove unwanted commented lines, white spaces, convert end-of-line characters to spaces and compress all uncompressed contents.

PdfCompressionOptions options = new PdfCompressionOptions();
options.OptimizePageContents = true;

Reducing PDF file size by disabling incremental updates

Incremental update is an option available to update the PDF file incrementally without rewriting the entire file. Here, changes are appended to the end of the file, leaving its original contents intact. Disabling the incremental update will rewrite the entire file, which results in a smaller PDF.

//Load the existing PDF document.
PdfLoadedDocument loadedDocument = new PdfLoadedDocument(@"input.pdf");
//Restructure the complete document.
loadedDocument.FileStructure.IncrementalUpdate = false;

See a world of document processing possibilities in Syncfusion's PDF Library as we unveil its features in interactive demonstrations.

Try Now

Reducing PDF file size by removing form fields

Removing or flattening form fields can help reduce your file size. When form fields and their values are not necessary, they can be removed. When they are necessary but require no further editing, they can be flattened. Both of these actions will result in a reduced file size.

public void RemoveFormFields(PdfLoadedDocument ldoc, bool flatten)
{
    if (flatten)
    {
        ldoc.Form.Flatten = true;
    }
    else
    {
        int count = ldoc.Form.Fields.Count;
        for (int i = count - 1; i >= 0; i--)
        {
            ldoc.Form.Fields.RemoveAt(i);
        }
    }
}

Reducing PDF file size by removing annotations

Removing or flattening annotations can help reduce your file size. Annotations and their contents can be removed when they are not needed. When they are necessary but do not require additional editing, they can be flattened. Both of these options will result in a reduced file size.

public void RemoveAnnotations(PdfLoadedDocument ldoc, bool flatten)
{
    foreach(PdfPageBase page in ldoc.Pages)
    {
        if (flatten)
        {
           page.Annotations.Flatten = true;
        }
        else
        {
            int count = page.Annotations.Count;
            for (int i = count - 1;i >= 0; i--)
            {
              page.Annotations.RemoveAt(i);
            }
        }
    }  
}

GitHub sample

For more details about this sample, refer to the complete compress PDF application demo on the GitHub repository.

Syncfusion’s high-performance PDF Library allows you to create PDF documents from scratch without Adobe dependencies.

Try It Free

Wrapping up

As you can see, Essential PDF provides a variety of optimizing mechanisms for compressing a PDF document. Use them effectively to generate compressed documents for increased efficiency and productivity in a document management system. Take a moment to peruse the documentation, where you’ll find other options and features, all with accompanying code examples.

If you are new to our PDF library, it is highly recommended that you follow our Getting Started guide.

If you’re already a Syncfusion user, you can download the product setup here else, you can download a free, 30-day trial here.

Have any questions or require clarifications about these features? Please let us know in the comments below, you can also contact us through our support forum or Direct-Trac. We are happy to assist you!

Related blogs

• HTML to PDF Conversion Using ASP.NET Core in Linux Docker
• Adding RTL Support to Your PDF in Xamarin
• Now your PDF documents are safer!
• Exporting the Data Grid to a specific PDF page in Xamarin.Forms
• Optical Character Recognition in PDF Using Tesseract Open-Source Engine

Tags: