Difference Between MVC Controller and Web API Controller in ASP.NET

Difference Between MVC Controller and Web API Controller in ASP.NET

ASP.NET provides two main types of controllers: MVC Controllers and Web API Controllers. While they may look similar at first glance, they serve different purposes and are used in different kinds of applications.

MVC Controller

• Designed for web applications that return HTML views to the browser.
• Typically used in ASP.NET MVC projects.
• Returns ViewResult, RedirectResult, or JsonResult, etc.
• Meant to handle user interaction, form submissions, and page rendering.

Example:

public class HomeController : Controller

{

    public IActionResult Index()

    {

        return View(); // returns an HTML view

    }

}

Web API Controller

• Designed for RESTful HTTP services that return data (usually JSON or XML).
• Used in ASP.NET Web API or ASP.NET Core Web API projects.
• Inherits from ControllerBase (not Controller) in ASP.NET Core.
• Returns data using ActionResult<T>, IEnumerable<T>, Ok(), NotFound(), etc.
• Optimized for building services consumed by mobile apps, JavaScript clients, or external systems.

Example:

[ApiController]

[Route("api/[controller]")]

public class ProductsController : ControllerBase

{

    [HttpGet]

    public ActionResult<IEnumerable<string>> Get()

    {

        return new string[] { "Product1", "Product2" };

    }

}

Comparison Table

Feature	MVC Controller	Web API Controller
Base class	Controller	ControllerBase
Primary purpose	Returns HTML views	Returns data (JSON, XML)
Used in	ASP.NET MVC	ASP.NET Web API / ASP.NET Core
Response type	ViewResult, RedirectResult, etc.	ActionResult<T>, Ok(), NotFound()
Returns	HTML pages	Data for clients
View support	Yes (View() method)	No view support
Use case	Browser-based web apps	API for mobile/web clients

Summary

• Use MVC Controller when building traditional web applications that serve HTML pages.
• Use Web API Controller when building RESTful services that return data to clients.

In ASP.NET Core, both MVC and Web API have been unified under a single framework, but their roles remain distinct depending on whether the application is serving views or data.