ControllerBase vs Controller in ASP.NET Core Web API

ControllerBase vs Controller in ASP.NET Core Web APIs

In ASP.NET Core Web APIs, you’ll see two common base classes for controllers: ControllerBase and Controller.

Here’s the difference explained simply:

🔹 ControllerBase

A lightweight base class designed specifically for Web APIs.

Provides features that are useful for building REST APIs:

• Access to HttpContext, Request, Response.
• Methods like Ok(), BadRequest(), NotFound(), Created(), etc. (for returning HTTP responses).
• Attribute routing ([HttpGet], [HttpPost], etc.).
• Does NOT include view support — no Razor views, no View() method.

🔹 Controller

Inherits from ControllerBase and adds view support.

Provides extra features for MVC applications:

• View() method (to return Razor views).
• PartialView(), ViewComponent().
• TempData dictionary (for passing data between requests).

🧱 Inheritance Structure

Class	Inherits From	Purpose
Controller	ControllerBase	For MVC apps with views
ControllerBase	Object	For Web APIs without view support

🎯 When to Use Each

Use ControllerBase when building Web APIs:

👉 Use ControllerBase when you are building a pure Web API that returns JSON/XML, not views.

• Lightweight and focused on HTTP request handling.
• No support for Razor views, ViewData, or ViewBag.
• Ideal for RESTful services and JSON responses.

Use Controller when building MVC apps:

👉 Use Controller when your application serves both API responses and views.

• Includes view rendering methods like View(), PartialView(), etc.
• Supports ViewData, TempData, and ViewBag.

🛠️ Feature Comparison

Feature	ControllerBase	Controller
View() method	❌	✅
ViewData, ViewBag	❌	✅
Json(), Ok(), BadRequest()	✅	✅
[ApiController] support	✅	✅
Razor View rendering	❌	✅

🧪 Example

// For Web API
[ApiController]
[Route("api/[controller]")]
public class ProductsController : ControllerBase
{
    [HttpGet]
    public IActionResult GetAll() => Ok(productService.GetAll());
}
  

// For MVC
public class HomeController : Controller
{
    public IActionResult Index() => View();
}
  

🧠 Pro Tip for Architects

If you're building a pure API layer, stick with ControllerBase — it’s leaner and avoids unnecessary MVC baggage. But if you're blending UI and API logic (not recommended for separation of concerns), Controller might be justified.