Introduction
Microsoft now officially recommends Minimal APIs for new ASP.NET Core projects, calling them the preferred approach for building fast HTTP APIs with minimal code and configuration. (Source) That recommendation did not exist when Controllers were the only option. It exists now, and it changes how you should think about starting a new .NET project.
Controllers are not going anywhere either. So, between Minimal APIs vs Controllers in .NET, the question is not which model is better. It's which one your project actually needs. Pick the wrong one and you'll either over-engineer a simple service or lose structure on a complex one.
This article covers what each model actually does, how they differ across five key dimensions, and which one you should choose.
How Minimal APIs and Controllers Actually Work in .NET
Before jumping into the comparison between Minimal APIs vs Controllers in .NET, let us understand what each of them actually does.
Controllers have been the standard way to build APIs in ASP.NET Core for years. You define a class, group your related endpoints inside it, and use attributes to handle routing and authorization. Most .NET teams are already familiar with this pattern.
But with Minimal APIs, you can skip most of that. You just have to map routes directly to functions inside Program.cs, with no class, no constructor, and no attributes. Your app only loads what it actually needs, which keeps startup faster and the code lighter.
The catch is that without a class to group things, all your routes sit in one place. And that gap between the two models becomes more visible as your project grows.
5 Key Differences Between Minimal APIs vs Controllers in .NET
When you're evaluating Minimal APIs and Controllers in .NET, the decision usually comes down to five things: performance, code structure, testing, middleware, and OpenAPI support.
1. Performance
A GitHub project tests show that Minimal APIs generally outperform Controllers on lightweight operations. The reason is how each of them processes requests. Controllers go through several processing steps on every request, which include routing, model binding, filters, and result execution. Minimal APIs skip most of that. So, the fewer steps between the request and the response, the faster the API runs.
With a microservice handling thousands of simple GET requests, you will notice the speed difference. But, for a larger API with complex data handling and multiple authorization layers, the gap becomes small enough that it should not be the deciding factor in your Minimal APIs vs Controllers decision.
2. Code Structure and Readability
Controllers keep your code organized by grouping related endpoints inside one class. All product operations sit inside ProductsController. All order operations sit inside OrdersController. New developers joining the project know exactly where to look, and the structure scales naturally as you add more endpoints.
Minimal APIs do not have that kind of grouping. Everything maps directly inside Program.cs. Five endpoints are fine. At fifty, the file becomes difficult to read and navigate. You can still work around this by splitting endpoints into separate files using extension methods or endpoint group classes, but that requires your team to plan and maintain that structure from day one.
3. Testability
Both models support testing, but the way you test them is different.
Controllers are easy to unit test. Since they are classes, you can create a ProductsController directly, pass in mock dependencies through the constructor, and call the action method without running the full application. Most .NET teams already follow this pattern.
Testing Minimal API endpoints works differently. You cannot call a lambda the way you would call a controller action. Instead, you need to write integration tests using WebApplicationFactory or TestServer, which runs the full application stack during the test. This gives you more accurate test coverage, but it also means more setup and slower test runs compared to unit tests.
For a new project, this is easy enough to plan around. For a team migrating an existing codebase with a large unit test suite built around Controllers, the shift in testing approach is worth considering before you make the switch. And, if your team needs help navigating that migration, you can consider going for .NET migration services from a trusted provider.
4. Handling Middleware, Filters, and Authorization
Controllers have a well-established way of handling things like logging, validation, and authorization across your endpoints. Action filters, result filters, exception filters, and authorization filters each have a defined place in the pipeline. You apply them at the controller or action level through attributes, which keeps the logic separate from your endpoint code.
Minimal APIs added support for endpoint filters through IEndpointFilter, which has been available since .NET 7 and continues to be supported in .NET 10. It works, but it does not cover everything the MVC filter pipeline does. Chaining multiple custom filters or handling complex authorization scenarios requires significantly more manual setup compared to Controllers.
For projects that depend heavily on filters or have complex authorization requirements, Controllers may be the better fit. Teams moving from Controllers to Minimal APIs should check how much of their existing filter logic can carry over before making the switch.
5. OpenAPI Support
Controllers have had OpenAPI support through Swagger for years. It was built into ASP.NET Core project templates from .NET 5 through .NET 8, which made generating API documentation a default part of the workflow for most teams.
Starting with .NET 9, ASP.NET Core dropped Swagger from its default templates and introduced native OpenAPI support through the Microsoft.AspNetCore.OpenApi package, generating OpenAPI 3.1 documents out of the box in .NET 10. Both Controllers and Minimal APIs work with this new setup, so the gap between the two models on this front has narrowed significantly.
That said, Minimal APIs require more manual effort to add useful metadata to your endpoints. Things like descriptions, response types, and parameter details do not get picked up automatically the way they do with Controllers. You have to add them explicitly, which takes extra time, especially on larger APIs with many endpoints.
Conclusion
The comparison between Minimal APIs vs Controllers in .NET does not have a universal answer. It depends on your project and architectural requirements.
Minimal APIs work best for focused, lightweight services. If you are building a microservice with a small number of endpoints, an API gateway, a proxy layer, or a serverless function where startup speed matters, Minimal APIs are a good choice. They also work well for new projects where the team is willing to manage their own code organization.
Controllers are better suited for larger projects. If your API has many endpoints, multiple developers contributing to it, or complex data handling that depends on model binding, Controllers give you the structure to manage that without things getting out of hand. They are also the more logical choice for existing ASP.NET Core projects where switching would cost more than it would save.
That said, you do not have to pick just one. ASP.NET Core supports both models in the same application, so you can use Controllers for existing endpoints and introduce Minimal APIs for new ones where it makes sense.
If you are still unsure about the right approach for your project, you can hire .NET developers with experience in both Minimal APIs and Controllers to help you make the right decision and implement it successfully.
Top comments (0)