Native AOT in .NET 10: Everything for C# Developers

#dotnet #csharp #performance #backend

Honestly, C# has had an incredible run over the last twenty years. It’s easily one of the most balanced languages out there, but I think people often forget how much of that heavy lifting is actually done by the JIT compiler. The way it optimizes everything on the fly at runtime is really what gives it that performance edge.

But in 2026, Microsoft introduced Native AOT in .NET 10. The performance floor has shifted. Now that .NET 10 has fully leaned into Native AOT, the trade-offs have changed. In a world of real-time AI and massive container clusters, 'fast enough' doesn't cut it. We need that immediate execution and smaller footprint to stay competitive, especially when you're scaling a thousand instances where every megabyte of overhead adds up.

This is where Native AOT (Ahead-of-Time compilation) in .NET 10 becomes a game changer.

Traditional Model (JIT)

Code compiled to Intermediate Language (IL)
JIT compiles IL → machine code at runtime
Pros: Flexibility, dynamic optimizations
Cons: Startup delay, higher memory usage

Native AOT Model

Code compiled directly into machine code during publish
No JIT compilation required at runtime
Pros: Instant startup, smaller footprint, improved security

Project: Native AOT vs JIT Performance Benchmark

🧱 Solution Structure
AOTPerformanceDemo/ ├── JitApp/ (Standard .NET Console App) ├── AotApp/ (Native AOT Console App) └── BenchmarkRunner/ (Measures performance)

Create the Solution

dotnet new sln -n AOTPerformanceDemo
dotnet new console -n JitApp
dotnet new console -n AotApp
dotnet new console -n BenchmarkRunner
dotnet sln add JitApp
dotnet sln add AotApp
dotnet sln add BenchmarkRunner

Add Sample Workload (Same Code in Both Apps)
Replace Program.cs in JitApp and AotApp:

using System.Diagnostics;

Console.WriteLine("App starting...");
var sw = Stopwatch.StartNew();
var result = HeavyComputation();

sw.Stop();
Console.WriteLine($"Result: {result}");
Console.WriteLine($"Execution Time: {sw.ElapsedMilliseconds} ms");

static long HeavyComputation()
{
    long sum = 0;    for (int i = 0; i < 10_000_000; i++)
    {
        sum += i;
    }    return sum;
}

Enable Native AOT (Only for AotApp)
Edit AotApp.csproj:

<Project Sdk="Microsoft.NET.Sdk">  
<PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>net10.0</TargetFramework>

    <!-- Enable Native AOT -->
    <PublishAot>true</PublishAot>    
    <!-- Reduce size -->
    <PublishTrimmed>true</PublishTrimmed>
    <InvariantGlobalization>true</InvariantGlobalization>
  </PropertyGroup>
</Project>

Build JIT App

dotnet build JitApp -c Release

Publish Native AOT App

dotnet publish AotApp -c Release -r win-x64

Benchmark Runner

using System.Diagnostics;

RunTest("JIT App", @"..\JitApp\bin\Release\net10.0\JitApp.exe");
RunTest("Native AOT App", @"..\AotApp\bin\Release\net10.0\win-x64\publish\AotApp.exe"); 

static void RunTest(string name, string path)
{
    Console.WriteLine($"\nRunning {name}..."); 
    var sw = Stopwatch.StartNew(); 

    var process = new Process
    {
        StartInfo = new ProcessStartInfo
        {
            FileName = path,
            RedirectStandardOutput = true,
            UseShellExecute = false
        }
    }; 

    process.Start();
    process.WaitForExit(); 
    sw.Stop(); 

    Console.WriteLine($"{name} Total Time (including startup): {sw.ElapsedMilliseconds} ms");
}

Run Benchmark

dotnet run --project BenchmarkRunner -c Release

Find the complete implementation and benchmarking project on GitHub

Result

Based on the results shown in my terminal, here is a visual comparison of the performance gap between the standard JIT approach and the new Native AOT in .NET 10.

The data reflects the following metrics from my run: