Global Exception Handling in .NET Core with Custom Middleware


In the ever-evolving landscape of software development, robust error handling is indispensable. Whether it's a minor glitch or a critical failure, how an application handles errors can profoundly impact user experience and system stability. In the .NET Core ecosystem, implementing global exception handling using custom middleware emerges as a powerful solution to centralize error management and enhance application resilience.

Understanding Global Exception Handling

Exception handling in .NET Core typically involves wrapping code blocks susceptible to errors within try-catch constructs. While effective, scattering error-handling logic throughout the codebase can lead to redundancy and code clutter. Global exception handling addresses this challenge by providing a centralized mechanism to intercept and process exceptions occurring across the application.

Custom Middleware

Middleware, a fundamental concept in ASP.NET Core, enables developers to build request-processing pipelines. Custom middleware extends this capability, allowing developers to inject additional logic into the pipeline to handle exceptions globally. By intercepting requests and responses, custom middleware provides a centralized point for error handling, promoting code cleanliness and maintainability.

Implementing Custom Exception Middleware

To implement global exception handling using custom middleware in .NET Core, follow these steps.

1. Create Custom Middleware: Develop a custom middleware component that intercepts exceptions within the request pipeline.

public class ExceptionMiddleware
    private readonly RequestDelegate _next;

    public ExceptionMiddleware(RequestDelegate next)
        _next = next;

    public async Task InvokeAsync(HttpContext context)
            await _next(context);
        catch (Exception ex)
            // Exception handling logic
            await HandleExceptionAsync(context, ex);

    private async Task HandleExceptionAsync(HttpContext context, Exception ex)
        // Handle and log the exception
        // Respond with appropriate error message
        context.Response.ContentType = "application/json";
        context.Response.StatusCode = (int)HttpStatusCode.InternalServerError;
        await context.Response.WriteAsync("An unexpected error occurred.");

2. Register Middleware: Register the custom middleware in the application's request processing pipeline within the Configure method of Startup.cs.

public void Configure(IApplicationBuilder app)
    // Additional middleware configurations...

Benefits of Custom Exception Middleware

Implementing global exception handling using custom middleware in .NET Core offers several benefits:

  • Centralized Error Handling: Consolidates error-handling logic into a single middleware component, simplifying code maintenance.
  • Uniform Error Responses: Ensures consistent error responses across the application, enhancing user experience and facilitating troubleshooting.
  • Enhanced Application Resilience: Provides a robust mechanism to gracefully handle exceptions, promoting application resilience and fault tolerance.


Global exception handling using custom middleware in .NET Core represents a paradigm shift in error management. By centralizing error-handling logic within the request pipeline, custom middleware streamlines code maintenance promotes consistency, and fortifies applications against unexpected failures. Embracing this approach empowers developers to build robust and resilient software solutions that deliver exceptional user experiences.