How to Read Barcodes from PDF in C# – Easy Methods with Code

Reading barcodes from PDF in C# is a common requirement in document processing workflows, especially when dealing with scanned forms or digital PDFs. In industries like logistics, finance, healthcare, and manufacturing, PDFs often contain barcodes—either embedded as images or rendered as vector graphics. Automating this process can reduce manual work and improve accuracy.

This guide shows how to read barcode from PDF with C# using two practical methods: extracting images embedded in PDF pages and scanning them, or rendering entire pages as images and detecting barcodes from the result. Both techniques support reliable recognition of 1D and 2D barcodes in different types of PDF documents.

Table of Contents

• Getting Started: Tools and Setup
• Step-by-Step: Read Barcodes from PDF in C#
  • Method 1: Extract Embedded Images and Detect Barcodes
  • Method 2: Render Page as Image and Scan
• Which Method Should You Use?
• Real-World Use Cases
• FAQ

Getting Started: Tools and Setup

To extract or recognize barcodes from PDF documents using C#, make sure your environment is set up correctly.

Here’s what you need:

• Any C# project that supports NuGet package installation (such as .NET Framework, .NET Core, or .NET).
• The following libraries, Spire.Barcode for .NET for barcode recognition and Spire.PDF for .NET for PDF processing, can be installed via NuGet Package Manager:

Install-Package Spire.Barcode
Install-Package Spire.PDF

Step-by-Step: Read Barcodes from PDF in C#

There are two ways to extract barcode data from PDF files. Choose one based on how the barcode is stored in the document.

Method 1: Extract Embedded Images and Detect Barcodes

This method is suitable for scanned PDF documents, where each page often contains a raster image with one or more barcodes. The BarcodeScanner.ScanOne() method can read one barcode from one image.

Code Example: Extract and Scan

using Spire.Barcode;
using Spire.Pdf;
using Spire.Pdf.Utilities;
using System.Drawing;

namespace ReadPDFBarcodeByExtracting
{
    class Program
    {
        static void Main(string[] args)
        {
            // Load a PDF file
            PdfDocument pdf = new PdfDocument();
            pdf.LoadFromFile("Sample.pdf");

            // Get a page and the image information on the page
            PdfPageBase page = pdf.Pages[0];
            PdfImageHelper imageHelper = new PdfImageHelper();
            PdfImageInfo[] imagesInfo = imageHelper.GetImagesInfo(page);

            // Loop through the image information
            int index = 0;
            foreach (PdfImageInfo imageInfo in imagesInfo)
            {
                // Get the image as an Image object
                Image image = imageInfo.Image;
                // Scan the barcode and output the result
                string scanResult = BarcodeScanner.ScanOne((Bitmap)image);
                Console.WriteLine($"Scan result of image {index + 1}:\n" + scanResult + "\n");
                index++;
            }
        }
    }
}

The following image shows a scanned PDF page and the barcode recognition result using Method 1 (extracting embedded images):

When to use: If the PDF is a scan or contains images with embedded barcodes.

You may also like: Generate Barcodes in C# (QR Code Example)

Method 2: Render Page as Image and Scan

When barcodes are drawn using vector elements (not embedded images), you can render each PDF page as a bitmap and perform barcode scanning on it. The BarcodeScanner.Scan() method can read multiple barcodes from one image.

Code Example: Render and Scan

using Spire.Barcode;
using Spire.Pdf;
using System.Drawing;

namespace ReadPDFBarcodeByExtracting
{
    class Program
    {
        static void Main(string[] args)
        {
            // Load a PDF file
            PdfDocument pdf = new PdfDocument();
            pdf.LoadFromFile("Sample.pdf");

            // Save each page as an image
            for (int i = 0; i < pdf.Pages.Count; i++)
            {
                Image image = pdf.SaveAsImage(i);
                // Read the barcodes on the image
                string[] scanResults = BarcodeScanner.Scan((Bitmap)image);
                // Output the results
                for (int j = 0; j < scanResults.Length; j++)
                {
                    Console.WriteLine($"Scan result of barcode {j + 1} on page {i + 1}:\n" + scanResults[j] + "\n");
                }
            }
        }
    }
}

Below is the result of applying Method 2 (rendering full PDF page) to detect vector barcodes on the page:

When to use: When barcodes are drawn on the page directly, not embedded as image elements.

Related article: Convert PDF Pages to Images in C#

Which Method Should You Use?

You can even combine both methods for maximum reliability when handling unpredictable document structures.

Real-World Use Cases

Here are some typical scenarios where barcode recognition from PDFs in C# proves useful:

• Logistics automation Extract tracking numbers and shipping IDs from scanned labels, dispatch forms, or signed delivery receipts in bulk.

• Invoice and billing systems Read barcode-based document IDs or payment references from digital or scanned invoices in batch processing tasks.

• Healthcare document digitization Automatically scan patient barcodes from lab reports, prescriptions, or admission forms in PDF format.

• Manufacturing and supply chain Recognize barcodes from packaging reports, quality control sheets, or equipment inspection PDFs.

• Educational institutions Process barcoded student IDs on scanned test forms or attendance sheets submitted as PDFs.

Tip: In many of these use cases, PDFs come from scanners or online systems, which may embed barcodes as images or page content—both cases are supported with the two methods introduced above.

Conclusion

Reading barcodes from PDF files in C# can be achieved reliably using either image extraction or full-page rendering. Whether you need to extract a barcode from a scanned document or recognize one embedded in PDF content, both methods provide flexible solutions for barcode recognition in C#.

FAQ

Q: Does this work with multi-page PDFs?
Yes. You can loop through all pages in the PDF and scan each one individually.

Q: Can I extract multiple barcodes per page?
Yes. The BarcodeScanner.Scan() method can detect and return all barcodes found on each image.

Q: Can I improve recognition accuracy by increasing resolution?
Yes. When rendering a PDF page to an image, you can set a higher DPI using PdfDocument.SaveAsImage(pageIndex: int, PdfImageType.Bitmap: PdfImageType, dpiX: int, dpiY: int). For example, 300 DPI is ideal for small or low-quality barcodes.

Q: Can I read barcodes from PDF using C# for free?
Yes. You can use Free Spire.Barcode for .NET and Free Spire.PDF for .NET to read barcodes from PDF files in C#. However, the free editions have feature limitations, such as page count or supported barcode types. If you need full functionality without restrictions, you can request a free temporary license to evaluate the commercial editions.