QR Code .NET Core Generator & Reader | IronQR

How Do You Install a QR Code Library in .NET Core?

To begin, open Visual Studio and click the create button to start a new project. Once you have assigned a project name, installing the library through the NuGet Package Manager takes seconds. While some developers might search for the QRCoder NuGet package, you can install the IronQR framework by running the following command in the Package Manager Console:

Install-Package IronQR

Alternatively, use the NuGet Package Manager UI by searching for "IronQR" and clicking the install button. The library provides a .NET implementation compatible with .NET Core 3.x, .NET 5, 6, 7, 8, 9, and 10, making it ideal for modern web development and multi-platform projects.

After installation, add the required using directives at the top of your file. IronQR integrates with IronSoftware.Drawing for cross-platform image handling, eliminating the need for platform-specific dependencies such as System.Drawing.Common, which was deprecated for cross-platform use in .NET 6 and later.

You can verify the installation succeeded by checking your project's package references in the .csproj file or by confirming the NuGet package appears in the Package Manager console output. Once installed, the IronQR API reference becomes available immediately.

How Do You Generate a QR Code?

The QrWriter class, often used alongside convenient extension methods, makes generating QR codes straightforward. Here is the source code for a complete example using top-level statements to generate a QR code in just a few lines of code:

using IronQr;
using IronSoftware.Drawing;

// Generate a QR code from input text
QrCode qrcode = QrWriter.Write("https://ironsoftware.com");

// Save as PNG image
AnyBitmap qrImage = qrcode.Save();
qrImage.SaveAs("website-qr.png");

using IronQr;
using IronSoftware.Drawing;

// Generate a QR code from input text
QrCode qrcode = QrWriter.Write("https://ironsoftware.com");

// Save as PNG image
AnyBitmap qrImage = qrcode.Save();
qrImage.SaveAs("website-qr.png");

What Are Error Correction Levels and Why Do They Matter?

Error correction determines how much damage a QR symbol can sustain while remaining scannable. This is one of the optional advanced features that allows for branding and durability. The QR code standard (ISO/IEC 18004) defines four levels of error correction, each trading data capacity for resilience.

Configure error correction using QrOptions:

using IronQr;
using IronSoftware.Drawing;

// Configure with high error correction level
var options = new QrOptions(QrErrorCorrectionLevel.High, 20);

// Generate QR code with options
QrCode qrcode = QrWriter.Write("Product-12345", options);
AnyBitmap qrImage = qrcode.Save();
qrImage.SaveAs("product-qr.png");

using IronQr;
using IronSoftware.Drawing;

// Configure with high error correction level
var options = new QrOptions(QrErrorCorrectionLevel.High, 20);

// Generate QR code with options
QrCode qrcode = QrWriter.Write("Product-12345", options);
AnyBitmap qrImage = qrcode.Save();
qrImage.SaveAs("product-qr.png");

How Do You Customize QR Code Appearance with Logo and Colors?

IronQR's QrStyleOptions enables brand-aligned QR code generation with custom colors, dimensions, and embedded logos. This is particularly useful for marketing materials, product packaging, and event tickets where visual consistency matters.

using IronQr;
using IronSoftware.Drawing;

var styleOptions = new QrStyleOptions
{
    Dimensions = 300,
    Margins = 10,
    Color = Color.DarkBlue,
    Logo = new QrLogo { Bitmap = AnyBitmap.FromFile("company-logo.png") }
};

QrCode qrcode = QrWriter.Write("https://yourcompany.com");
AnyBitmap qrImage = qrcode.Save(styleOptions);
qrImage.SaveAs("branded-qr.png");

using IronQr;
using IronSoftware.Drawing;

var styleOptions = new QrStyleOptions
{
    Dimensions = 300,
    Margins = 10,
    Color = Color.DarkBlue,
    Logo = new QrLogo { Bitmap = AnyBitmap.FromFile("company-logo.png") }
};

QrCode qrcode = QrWriter.Write("https://yourcompany.com");
AnyBitmap qrImage = qrcode.Save(styleOptions);
qrImage.SaveAs("branded-qr.png");

How Do You Generate QR Codes in ASP.NET Core?

Integrating QR code generation into ASP.NET Core follows the Model View Controller pattern. Here is a HomeController class implementation that returns a QR code image directly from an action method:

using IronQr;
using IronSoftware.Drawing;
using Microsoft.AspNetCore.Mvc;

namespace Examples
{
    public class HomeController : Controller
    {
        public IActionResult GenerateQR(string content)
        {
            QrCode myQr = QrWriter.Write(content);
            AnyBitmap qrImage = myQr.Save();
            byte[] imageBytes = qrImage.ExportBytes();
            return File(imageBytes, "image/png");
        }
    }
}

using IronQr;
using IronSoftware.Drawing;
using Microsoft.AspNetCore.Mvc;

namespace Examples
{
    public class HomeController : Controller
    {
        public IActionResult GenerateQR(string content)
        {
            QrCode myQr = QrWriter.Write(content);
            AnyBitmap qrImage = myQr.Save();
            byte[] imageBytes = qrImage.ExportBytes();
            return File(imageBytes, "image/png");
        }
    }
}

This endpoint accepts QR code data as a parameter and returns the generated PNG image directly. The approach works with ASP.NET Core Web API projects and Razor views alike.

For production ASP.NET Core applications, consider caching frequently generated QR codes using IMemoryCache or IDistributedCache to reduce CPU overhead. QR codes for static URLs, product identifiers, or event links do not change between requests and are ideal candidates for caching.

You can also integrate IronQR into a Minimal API endpoint. The ASP.NET Core integration tutorial provides a complete example including dependency injection patterns and how to serve QR code images from a Blazor component.

Registering IronQR's license key in Program.cs using the top-level statement pattern keeps startup configuration clean:

using IronQr;

IronQr.License.LicenseKey = "YOUR-LICENSE-KEY";

using IronQr;

IronQr.License.LicenseKey = "YOUR-LICENSE-KEY";

Set the license key before calling any IronQR methods. In development, you can apply a free trial key obtained from the IronQR licensing page.

How Do You Encode Japanese Unicode Text?

IronQR supports encoding Japanese Unicode text through Kanji mode, which efficiently encodes Japanese unicode characters using fewer data segments than standard encoding. This reduces the QR code's version (size) for the same content, producing a less complex symbol that scans faster.

using IronQr;
using IronSoftware.Drawing;

// Generate QR that encodes Japanese Unicode text
QrCode japaneseQr = QrWriter.Write("こんにちは世界");
AnyBitmap qrImage = japaneseQr.Save();
qrImage.SaveAs("japanese-qr.png");

using IronQr;
using IronSoftware.Drawing;

// Generate QR that encodes Japanese Unicode text
QrCode japaneseQr = QrWriter.Write("こんにちは世界");
AnyBitmap qrImage = japaneseQr.Save();
qrImage.SaveAs("japanese-qr.png");

How Do You Read QR Codes with Machine Learning?

IronQR distinguishes itself through its machine learning-powered QR reader. The ML model achieves high accuracy even reading QR codes from angles or partially obscured images -- a significant advantage over traditional threshold-based detection algorithms used in many open source alternatives.

using IronQr;
using IronSoftware.Drawing;

// Load image containing QR code
AnyBitmap inputBmp = AnyBitmap.FromFile("scanned-document.png");
QrImageInput imageInput = new QrImageInput(inputBmp);

// Read with ML-powered detection
QrReader reader = new QrReader();
IEnumerable<QrResult> results = reader.Read(imageInput);

foreach (var result in results)
{
    Console.WriteLine($"Found: {result.Value}");
}

using IronQr;
using IronSoftware.Drawing;

// Load image containing QR code
AnyBitmap inputBmp = AnyBitmap.FromFile("scanned-document.png");
QrImageInput imageInput = new QrImageInput(inputBmp);

// Read with ML-powered detection
QrReader reader = new QrReader();
IEnumerable<QrResult> results = reader.Read(imageInput);

foreach (var result in results)
{
    Console.WriteLine($"Found: {result.Value}");
}

How Does Cross-Platform Support Work?

Unlike solutions dependent on System.Drawing.Common (deprecated for cross-platform use in .NET 6+), IronQR uses IronSoftware.Drawing for true multi-platform projects. Your code runs consistently across Windows, macOS, Linux, iOS, and Android. For multi-platform projects, SkiaSharp alternatives are unnecessary -- IronQR handles platform abstraction internally.

The .NET cross-platform documentation explains the broader platform compatibility story for .NET 10. IronQR aligns with these principles by avoiding platform-specific APIs entirely.

IronQR supports the following deployment targets:

• .NET 10, 9, 8, 7, 6 -- all modern .NET versions
• .NET Core 3.x -- for applications that have not yet migrated to modern .NET
• Xamarin and MAUI -- for mobile application development
• Azure Functions and AWS Lambda -- for serverless workloads

When running in Docker containers, no additional system packages are needed beyond the standard .NET runtime image. This simplifies your Dockerfile compared to libraries that require native GDI+ dependencies. The IronQR deployment guide covers configuration for containerized and cloud environments.

How Do You Compare IronQR to Other .NET QR Libraries?

Several .NET QR code libraries exist, each with different trade-offs. Understanding the differences helps you choose the right tool for your project.

QRCoder is an open source library with an MIT license. It works well for straightforward QR code generation but does not include QR code reading capabilities or machine learning-powered detection. Its output options are more limited compared to IronQR's styled output support.

ZXing.NET is a C# port of the Java ZXing library. It supports both reading and writing but relies on traditional computer vision techniques that struggle with damaged or rotated codes. Cross-platform image handling requires additional setup.

IronQR provides generation and reading in a single package, with enterprise licensing that includes dedicated support. The ML-powered reader, styled output, and IronSoftware.Drawing integration make it a more complete solution for production applications.

For a detailed feature comparison, see the IronQR vs QRCoder comparison and the IronQR vs ZXing comparison articles.

What Are Your Next Steps?

IronQR provides a complete solution for QR code generation and reading in .NET Core. By handling complex payload generators and the assembly of raw modules and QrCodeData data automatically, it simplifies the development cycle. Whether you need a simple open source library alternative or a system with optional advanced features, IronQR's cross-platform architecture ensures reliable operation.

To continue building with IronQR, explore these resources:

• IronQR NuGet package -- install the latest stable version
• IronQR API reference -- full class and method documentation
• QR code examples -- copy-paste ready code for common scenarios
• IronQR tutorials -- step-by-step guides for specific use cases
• Licensing options -- choose the right plan for your project

Start your free trial to unlock IronQR's full potential without any upfront commitment.