What’s New In .NET 9? Top Features and Updates Not To Miss

Quick Summary

Table of Contents

Introduction

As the tech landscape continues to evolve, developers and businesses alike need new tools and enhancements to keep up their pace with innovation and scalability. NET 9 has arrived now as a game-changer, bringing a comprehensive set of new features, updates, and improvements that focus on enhancing performance, simplifying development processes, and extending the capabilities of the framework. The .NET team has been consistently trying to address the needs and points of the developers, which is why the all-new .NET 9 has been released.

Let us move forward to understand what’s new in .NET 9, how the new updates can make development more efficient, and why this latest version is a must-adopt for developing scalable, high-performance, and future-ready applications.

What’s New in .NET 9?

.NET 9 is here, and it brings a huge wave of new updates and features, and a great impact along with it that shapes the future of software development. The new release of .NET 9,0 focuses on enhancing performance, expanding cross-platform capabilities, and helping developers with various cutting-edge tools and libraries. Let us have a glance at the top features to understand what’s new in .NET 9 and how the latest release has something for everyone.

.NET Runtime: Better Core Of The Framework

Since the emergence of .NET, you must know that its greatest strength has always been its runtime performance. Another thing is that .NET 9 is built on this strong foundation with even better improvements and features. Talking about the .NET 9 runtime performance, it has been designed to be fully optimized to provide superior performance, enhanced developer experience, and ensure the developed apps are more efficient, powerful, and resilient. The new attributes in .NET 9.0 make it possible to define feature switches that can be used through libraries to toggle areas of functionality.

JIT Compilation

The JIT (Just-In-Time) compilation in .NET 9 has been optimized completely for faster startup times, utilizing the tiered compilation more efficiently. Some specific optimizations were previously available only in Ahead-Of-Time (AOT) compilation but are now available in JIT compilation. With JIT compilation, your application can start up within seconds due to lower overhead. While other high-impact methods can be easily compiled and optimized as they are executed on the go.

public static int SumArrayOptimized(int[] arr)
{
    int sum = 0;
    for (int i = 0; i < arr.Length; i++)
    {
        sum += arr[i];
    }
    return sum;
}

Garbage Collection (GC)

The garbage collector in .NET 9 is optimized for enhanced performance, especially when it comes to applications with high memory demands. The garbage collector also introduces improvements that reduce latency for large object heap (LOH) allocations that deliver smooth real-time performance in memory-intensive environments.

.NET Libraries: Expanded Tools and Flexibility

.NET 9 libraries have received an array of updates and improvements focussing on enhancing performance, security, and developer experiences. The key updates and enhancements in .NET 9 libraries also include improvements in cryptography, file I/O, and JSON serialization. Through these improvements, developers can get a more powerful and flexible set of tools.

Enhanced JSON Serialization

In .NET 9, JSON serialization has been a key focus for significant enhancements, with many improvements to System.Text.Json which makes it faster and more seamless to work with structured data. The latest updates simplify JSON serialization and deserialization of record types and immutable structures, which further eliminates the need to deal with complex configurations.



public record Product(string Name, decimal Price);
var product = new Product("Smartphone", 999.99m);
string jsonOutput = JsonSerializer.Serialize(product);
Console.WriteLine(jsonOutput); // Output: {"Title":"Smartphone","Cost":999.99}
// Deserialize the JSON back to a record
var deserialized = JsonSerializer.Deserialize(jsonOutput);
Console.WriteLine(deserialized?.Name); // Output: Smartphone

Cryptography Enhancements

The good news about the cryptography library in .NET 9 is that it now supports hardware-accelerated cryptographic algorithms. This will facilitate faster and more efficient operations like hashing and encryption. Such improvements will utilize hardware instructions to deliver superior performance.



using System.Security.Cryptography;
using System.Text;
var data = Encoding.UTF8.GetBytes("Have A Great Day, .NET 9!");
var hash = SHA256.HashData(data);
Console.WriteLine(Convert.ToBase64String(hash));

File I/O Enhancements

Well, file reading and writing in .NET 9 are optimized for enhanced performance, especially in asynchronous scenarios. These improvements are particularly valuable for applications handling large files or executing concurrent file operations.



using (FileStream fs = new FileStream("sample.txt", FileMode.Open, FileAccess.Read, FileShare.Read, 4096, true))
{
    byte[] buffer = new byte[fs.Length];
    await fs.ReadAsync(buffer, 0, buffer.Length);
    Console.WriteLine("File Content Has Been Read Successfully.");
}

.NET MAUI: Redefining Cross-platform Development

Every curious enthusiast should know that .NET Multi-platform App UI (MAUI) continues to evolve at a gradual pace. However, with .NET 9, it has become significantly easier to develop cross-platform apps for Windows, macOS, iOS, and Android.

Single Project Structure

.NET MAUI is now supporting a unified project structure, which allows developers to target multiple platforms within a single project. This will simplify resource management, code sharing, and platform-specific logic to make cross-platform development more efficient and organized.



  net9.0-ios;net9.0-android

This kind of structure facilitates seamless multi-platform development while reducing complexity and accelerating your workflow. With .NET 9 and MAUI, building consistent, responsive, and performant apps across platforms has never been easier.

Improved Native AOT (Ahead-of-time) Compilation

.NET 9 is moving forward in Ahead-of-Time (AOT) compilation, providing both developers and end-users with various improvements and benefits. Native AOT compiled managed code directly into native code, which further results in smaller, faster, and more optimized binaries. The new update will aim for:

Improved Performance: Faster startup times and reduced memory consumption due to minimizing the reliance on Just-In-Time (JIT) compilation during runtime.

Smaller Footprint: Apps that are compiled with Native AOT have significantly smaller file sizes, making them ideal for resource-constrained devices.

Cross-Platform Support: AOT compilation offers enhanced compatibility for apps running on Linux, macOS, and Windows to ensure consistency across systems.

Advanced Support For Cloud-Native Apps

.NET 9 introduces powerful cloud-native features that enhance its integration with modern cloud environments. The cloud-native features of .NET 9 are indeed excellent and that is what makes .NET 9 an excellent choice for building scalable and dynamic apps. Some key updates include:

Seamless Integration with Cloud Providers
.NET 9 provides built-in support to users so that they can integrate easily with leading cloud providers like Azure, AWS, and Google Cloud Platform. It simplifies the process of integrating apps with these ecosystems and allows developer to use advanced cloud capabilities.

Simplified Microservices Architecture
With optimized APIs and networking enhancements, .NET 9 provides powerful support for microservices. So, developers can build and maintain distributed applications more efficiently.

Enhanced Containerization
.NET 9 reduces deployment times with smaller container images and an optimized runtime designed for Docker. That means streamlining app lifecycles and improving portability across environments becomes feasible with .NET 9.

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Integrated SDK Experience

.NET 9 actually focuses on enhancing the developer experience by unifying SDKs across diverse platforms. With the integrated SDK experience, it will be feasible to craft a seamless and consistent workflow. Here are some of the key highlights of this unified SDK experience.

Single SDK for All Application Types
With the use of .NET 9, developers can utilize a single SDK to develop apps for web, mobile, desktop, IoT, and cloud platforms. This will certainly reduce complexity and improve efficiency.

Smarter CLI
The redefined Command Line Interface (CLI) simplifies tasks for developers like building, testing, and deploying apps across diverse environments and platforms.

Standardized Project Templates
With the new project templates, developers get standardized project setups and can enable faster project initialization which increases the overall productivity.

ASP.NET Core: Improved Web Development

ASP.NET Core in .NET 9 brings significant updates that help make web development faster, easier, and more secure. Here are some crucial changes that .NET 9 offers:

Blazor Enhancements
Blazor now includes a variety of new components and capabilities, which makes it super easy for developers to create interactive web applications without relying on JavaScript. In the end, the entire development process becomes straightforward and optimized.

Improved Middleware
The all-new middleware updates are enhancing the request processing and allows for fast routing as well as efficient handling for complex web applications.

Advanced Security Features
ASP.NET Core now supports a set of powerful security protocols like OAuth2 and OpenID Connect. These security features not only simplify the implementation of secure web apps but also ensure compliance with modern security standards.

C# 13 Updates

.NET 9 also brings out the language updates, especially for C# 13. Yes, C# 13 has got some powerful enhancements and improvements that boost flexibility, performance, and productivity for developers. Have a look at what new enhancements are making development easier.

Enhanced params Collections: The params keyword in C# now supports collections like List and Span. This extension allows developers to handle variable arguments more flexibly.



public void PrintNumbers(params List numbers)
{
    Console.WriteLine(string.Join(", ", numbers));
}
PrintNumbers(new List { 1, 2, 3, 4, 5 });

Improved Thread Synchronization: The new System.Threading.Lock can further simplify thread safety with Lock.EnterScope(). This would certainly provide you with a cleaner and safer locking mechanism.



using (myLock.EnterScope())
{
    Console.WriteLine("Thread-safe operation.");
}
Now, this kind of lock is more preferred. That means developers must use below code
private readonly Lock _lockObj = new();
...
lock(_lock)

Yes, you should write the above code at the instances where you were using the following code:
private object _lock = new object();
...
lock(_lock)

New Escape Sequence: In C# 13, you will find a new \e escape sequence that represents the ESCAPE character (U+001B). The escape sequence is added to make it easier for developers to include the ESCAPE character in strings.



string escapeChar = "\e";
Console.WriteLine($"Escape character: {escapeChar}");

Async Enhancements: ref and unsafe variables can now be used in asynchronous methods and iterators, expanding their versatility in modern workflows. Such enhancements enable the use of types like System.ReadOnlySpan in various contexts.

ML.NET 4.0

ML.NET 4.0 introduces the integration of the machine learning framework into .NET. The ML.NET provides support for loading ONMX models as streams, which makes it easier to deploy machine learning models in environments with limited resources or strict file dependencies. With the emergence of this feature, you can enable the seamless integration of AI models into your .NET apps without any dependency on file paths.

Here is a quick example of Loading and Using ONNX Models as Streams



using var modelStream = File.OpenRead("model.onnx");
var onnxModel = mlContext.Model.Load(modelStream, out _);
var predictionEngine = mlContext.Model.CreatePredictionEngine(onnxModel);
var prediction = predictionEngine.Predict(new InputData { Feature = "example" });
Console.WriteLine($"Prediction: {prediction.Label}")

.NET 8 vs .NET 9 - A Quick Comparison

.NET 9 was designed and developed based on the advancements of .NET 8. The new updates on .NET 9 introduce enhanced performance, expanded libraries, and better cloud-native integration. Here’s a quick comparison of .NET 8 vs .NET 9 that highlights key differences between the two versions:

Aspect	.NET 8	.NET 9
Performance	Improved runtime and garbage collection	Further optimized garbage collection and runtime for high-memory scenarios
Native AOT	Introduced Native AOT for faster startup times and smaller binaries	Refined Native AOT with smaller binaries and broader compatibility
Garbage Collection	Basic optimizations	Efficient LOH allocations
SDK Experience	Multiple SDKs for different platforms	Unified SDK for all platforms, simplifying development workflows
Blazor Server	Initial support	Latency and scalability enhancements
Cloud-Native Features	Basic support for containerization and microservices	Advanced microservices support, optimized containerization, and seamless cloud integration
.NET MAUI	Early stages	Enhanced single-project support
Library Enhancements	Basic updates in libraries for cryptography and JSON serialization	Expanded libraries with hardware-accelerated cryptography and enhanced file I/O
C# Updates	C# 12 with features like required properties and list patterns	C# 13 with raw string literals, primary constructors, and enhanced patterns

Conclusion

We hope that you now have a clear idea about what’s new in .NET 9 through its latest features, additions, and advancements that we have covered in this blog post. .NET 9 is indeed packed with powerful updates like enhanced runtime performance, C# 13 features, modernized libraries, streamlined tools, and more. From improved cross-platform capabilities with .NET MAUI to advanced cloud-native support, .NET 9 empowers developers to build scalable, high-performance, and resilient solutions.

In case you are planning to upgrade your apps to .NET 9 or want to utilize the maximum potential of the framework, partnering with a reliable .NET development company like Bacancy can ensure your project’s success. .NET 9 indeed sets a new standard for flexibility, efficiency, and performance in the .NET ecosystem.