Singleton vs Scoped vs Transient — Complete Guide

Singleton vs Scoped vs Transient — Complete Guide: free step-by-step lesson with examples, common mistakes, and interview tips — part of ASP.NET Core MVC Tutorial on Toolliyo Academy.

8 min read Updated 6/25/2026

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ASP.NET Core MVC Tutorial · Lesson 66 of 200

Singleton vs Scoped vs Transient

Getting Started ✓ → Core MVC ✓ → Data & Security ✓ → Production → Career

Advanced · 6 — Advanced MVC · ~10 min · Section 7: Dependency Injection

What is this?

Singleton vs Scoped vs Transient is how ASP.NET Core wires services into controllers without new-ing everything by hand.

Why should you care?

Testable, maintainable ShopNest code depends on dependency injection.

See it live — copy this example

Create an MVC project (dotnet new mvc), add the code, and run dotnet run.

// Singleton vs Scoped vs Transient — ShopNest.Mvc example
public class HomeController : Controller
{
    public IActionResult Index() => View();
}

Run Example »

Edit the code and click Run — like W3Schools Try it Yourself.

Code

Result

What happened?

Study the example line by line.
Each part connects to Singleton vs Scoped vs Transient.
Edit one line, save, and run dotnet run to see what changes.

Try it yourself

Register the service in Program.cs.
Inject the interface in a controller constructor.
Run the app and confirm the feature works.
Change text or labels in the example and run again — watch the browser update.
Break the code on purpose (remove a semicolon), read the error message, then fix it.

Remember

You learned what Singleton vs Scoped vs Transient is and when to use it. Practice by changing the example yourself. Explain it in your own words before moving on.