ASP.NET Core Web API Tutorial
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201 HTTP Status Code in ASP.NET Core Web API — Complete Guide

201 HTTP Status Code in ASP.NET Core Web API — Complete Guide: free step-by-step lesson with examples, common mistakes, and interview tips — part of ASP.NET Core Web API Tutorial on Toolliyo Academy.

8 min read Updated 6/25/2026
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ASP.NET Core Web API Tutorial · Lesson 39 of 175

201 HTTP Status Code in ASP.NET Core Web API

Beginner ✓ → Intermediate → Advanced → Professional

Intermediate · 2 — Data & pipeline · ~6 min · Module 4: Return Types and Status Codes

What is this?

201 Created tells the client: resource was created. ASP.NET Core returns it with Ok(), Created(), NotFound(), StatusCode(201), and similar helpers.

Why should you care?

Mobile and SPA clients branch on status codes — not English messages. Wrong codes break retry logic and confuse Postman tests.

See it live — copy this example

Create a Web API (dotnet new webapi), paste the example, run dotnet run, test in Swagger.

var created = await _svc.CreateAsync(dto, ct);
return CreatedAtAction(nameof(GetById), new { id = created.Id }, created);

Run Example »

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

Code
Result

What happened?

  • Location header often points to new URL
  • Follow the practice steps below on ShopNest.API — typing code yourself is the fastest way to learn.

Try it yourself

  1. Trigger a 201 response in ShopNest.API (Swagger or Postman).
  2. Inspect status line and response body in the Network tab.
  3. Compare with the lesson on 400 — note the difference.
  4. Change a route URL or DTO property and save — test again in Swagger or curl.
  5. Return the wrong status code on purpose (404 instead of 200) and see what the client shows.

Remember

201 = Created. Use the right helper method in ControllerBase. Clients depend on the number, not your message text.

ASP.NET Core Web API Tutorial
Course syllabus
Module 1: Introduction and Environment Setup Introduction to ASP.NET Core Framework — Complete Guide .NET Core vs .NET Framework Code Execution Process — Complete Guide ASP.NET Core Environment Setup — Complete Guide Download and Install .NET Core SDK — Complete Guide Download and Install Visual Studio 2022 — Complete Guide Download and Install Visual Studio Code — Complete Guide Download and Install SQL Server 2022 — Complete Guide Download and Install SSMS — Complete Guide Download and Install Postman and Fiddler — Complete Guide
Module 2: Web API Basics Introduction to ASP.NET Core Web API — Complete Guide HTTP (HyperText Transport Protocol) — Complete Guide Creating ASP.NET Core Web API Project using .NET Core CLI — Complete Guide How to Test ASP.NET Core Web API Using Postman — Complete Guide Creating ASP.NET Core Web API Project in Visual Studio — Complete Guide Default ASP.NET Core Web API Files and Folders — Complete Guide ASP.NET Core Web API Project File — Complete Guide ASP.NET Core Web API Main Method — Complete Guide Controllers in ASP.NET Core Web API — Complete Guide Models in ASP.NET Core Web API — Complete Guide Services in ASP.NET Core Web API — Complete Guide ASP.NET Core Web API AppSettings.json file — Complete Guide ASP.NET Core In-Process Hosting Model — Complete Guide ASP.NET Core Kestrel Web Server — Complete Guide ASP.NET Core Out of Process Hosting Model — Complete Guide Hosting Model Interview Questions and Answers — Complete Guide Dependency Injection in ASP.NET Core Web API — Complete Guide Singleton vs Scoped vs Transient in ASP.NET Core Web API — Complete Guide Swagger API in ASP.NET Core Web API — Complete Guide
Module 3: Routing Routing in ASP.NET Core Web API — Complete Guide Route Parameters and Query Strings in Routing — Complete Guide Multiple URLs for a Single Resource in ASP.NET Core Web API — Complete Guide Token Replacement in ASP.NET Core Web API — Complete Guide Route Prefix in ASP.NET Core Web API — Complete Guide Route Constraints in ASP.NET Core Web API — Complete Guide How Routing Works in ASP.NET Core Web API — Complete Guide
Module 4: Return Types and Status Codes Action Return Types in ASP.NET Core Web API — Complete Guide HTTP Status Codes in ASP.NET Core Web API — Complete Guide 200 HTTP Status Code in ASP.NET Core Web API — Complete Guide 201 HTTP Status Code in ASP.NET Core Web API — Complete Guide 202 HTTP Status Code in ASP.NET Core Web API — Complete Guide 204 HTTP Status Code in ASP.NET Core Web API — Complete Guide 301 HTTP Status Code in ASP.NET Core Web API — Complete Guide 302 HTTP Status Code in ASP.NET Core Web API — Complete Guide 304 HTTP Status Code in ASP.NET Core Web API — Complete Guide 400 HTTP Status Code in ASP.NET Core Web API — Complete Guide 401 HTTP Status Code in ASP.NET Core Web API — Complete Guide 403 HTTP Status Code in ASP.NET Core Web API — Complete Guide 404 HTTP Status Code in ASP.NET Core Web API — Complete Guide 405 HTTP Status Code in ASP.NET Core Web API — Complete Guide Configure Allowed HTTP Methods Globally in ASP.NET Core Web API — Complete Guide 500 HTTP Status Code in ASP.NET Core Web API — Complete Guide 501 HTTP Status Code in ASP.NET Core Web API — Complete Guide 503 HTTP Status Code in ASP.NET Core Web API — Complete Guide 504 HTTP Status Code in ASP.NET Core Web API — Complete Guide
Module 5: Model Binding Model Binding in ASP.NET Core Web API — Complete Guide Model Binding using FromForm in ASP.NET Core Web API — Complete Guide Model Binding using FromQuery in ASP.NET Core Web API — Complete Guide Model Binding Using FromRoute in ASP.NET Core Web API — Complete Guide Model Binding Using FromHeader in ASP.NET Core Web API — Complete Guide Model Binding Using FromBody in ASP.NET Core Web API — Complete Guide Custom Model Binding in ASP.NET Core Web API — Complete Guide How to Apply Binding Attributes to Model Properties in ASP.NET Core Web API — Complete Guide Content Negotiation in ASP.NET Core Web API — Complete Guide Produces and Consumes Attributes in ASP.NET Core Web API — Complete Guide Exclude Properties from Model Binding in ASP.NET Core Web API — Complete Guide Validation using Data Annotations in ASP.NET Core Web API — Complete Guide
Module 6: Entity Framework Core A Brief Introduction to Entity Framework Core — Complete Guide Entity Framework Core in ASP.NET Core Web API with SQL Server — Complete Guide Entity States in Entity Framework Core — Complete Guide Relationships in Entity Framework Core — Complete Guide Lazy Loading in Entity Framework Core — Complete Guide Eager Loading in Entity Framework Core — Complete Guide Explicit Loading in Entity Framework Core — Complete Guide Default Conventions in EF Core — Complete Guide Data Annotation Attributes in EF Core — Complete Guide Fluent API Configurations in EF Core — Complete Guide Fluent API Global Configurations in EF Core — Complete Guide Fluent API Entity Configurations in EF Core — Complete Guide Fluent API Property Configuration in EF Core — Complete Guide EF Core Inheritance — Complete Guide EF Core Transactions — Complete Guide Entity Framework Core with Stored Procedures — Complete Guide EF Core Database First Approach — Complete Guide
Module 7: AutoMapper and Mapperly Automapper in ASP.NET Core Web API — Complete Guide Automapper Complex Type Mapping in ASP.NET Core Web API — Complete Guide Mapping Complex Type to Primitive Type using AutoMapper in ASP.NET Core Web API — Complete Guide Automapper Reverse Mapping in ASP.NET Core Web API — Complete Guide Automapper Conditional Mapping in ASP.NET Core Web API — Complete Guide Ignore Property Mapping using Automapper in ASP.NET Core Web API — Complete Guide Automapper Null Substitution in ASP.NET Core Web API — Complete Guide AutoMapper Advanced Concepts in ASP.NET Core Web API — Complete Guide AutoMapper Real-time Example in ASP.NET Core Web API — Complete Guide Mapperly in ASP.NET Core Web API — Complete Guide Mapperly Real-time Example in ASP.NET Core Web API — Complete Guide
Module 8: HTTP Methods HTTP Methods in ASP.NET Core Web API — Complete Guide HTTP GET Method in ASP.NET Core Web API — Complete Guide HTTP Post Method in ASP.NET Core Web API — Complete Guide HTTP PUT Method in ASP.NET Core Web API — Complete Guide HTTP PATCH Method in ASP.NET Core Web API — Complete Guide HTTP DELETE Method in ASP.NET Core Web API — Complete Guide HTTP HEAD Method in ASP.NET Core Web API — Complete Guide HTTP OPTIONS Method in ASP.NET Core Web API — Complete Guide
Module 9: Logging Logging in ASP.NET Core Web API — Complete Guide Custom Logging Provider in ASP.NET Core Web API — Complete Guide How to Implement Serilog in ASP.NET Core Web API — Complete Guide Serilog, Elasticsearch, and Kibana in ASP.NET Core Web API — Complete Guide How to Implement Logging using nLog in ASP.NET Core Web API — Complete Guide Logging to Database using NLog in ASP.NET Core Web API — Complete Guide Serilog vs NLog in ASP.NET Core Web API — Complete Guide
Module 10: Caching Caching in ASP.NET Core Web API — Complete Guide In-Memory Caching in ASP.NET Core Web API — Complete Guide Custom In-Memory Cache in ASP.NET Core — Complete Guide How to Implement Redis Cache in ASP.NET Core — Complete Guide In-Memory Caching vs Distributed Caching in ASP.NET Core — Complete Guide NCache Cluster and Its Types in Distributed Caching — Complete Guide How to Download and Install NCache in Windows — Complete Guide How to Implement NCache in ASP.NET Core Web API — Complete Guide Response Caching in ASP.NET Core Web API — Complete Guide
Module 11: FluentValidation Fluent API Validation in ASP.NET Core Web API — Complete Guide Fluent API Async Validators in ASP.NET Core Web API — Complete Guide Fluent API Custom Validators in ASP.NET Core Web API — Complete Guide Fluent API Conditional Validations in ASP.NET Core Web API — Complete Guide Validate Nested Complex or Collection Property using Fluent API — Complete Guide
Module 12: Filters Filters in ASP.NET Core Web API — Complete Guide Authorization Filters in ASP.NET Core Web API — Complete Guide Custom Authorization Filter in ASP.NET Core Web API — Complete Guide Resource Filters in ASP.NET Core Web API — Complete Guide Action Filters in ASP.NET Core Web API — Complete Guide Result Filters in ASP.NET Core Web API — Complete Guide Exception Filters in ASP.NET Core Web API — Complete Guide ServiceFilter vs TypeFilter in ASP.NET Core Web API — Complete Guide ASP.NET Core Request Processing Life Cycle — Complete Guide
Module 13: Security How to Store Password in Hash Format in ASP.NET Core Web API — Complete Guide HMAC Authentication in ASP.NET Core Web API — Complete Guide Encryption and Decryption in ASP.NET Core Web API — Complete Guide Asymmetric Encryption in ASP.NET Core Web API — Complete Guide Authentication and Authorization in Web APIs — Complete Guide Basic Authentication in ASP.NET Core Web API — Complete Guide Role-Based Basic Authentication in ASP.NET Core Web API — Complete Guide JWT Authentication in ASP.NET Core — Complete Guide CORS in ASP.NET Core Web API — Complete Guide JWT – ASP.NET Core Web API — Complete Guide JWT Authentication in ASP.NET Core Web API — Complete Guide Resource Server and Client Applications with JWT Authentication — Complete Guide Refresh Token in ASP.NET Core Web API using JWT Authentication — Complete Guide Revoke Refresh Tokens in JWT-Based Token Authentication — Complete Guide Role Based JWT Authentication in ASP.NET Core Web API — Complete Guide SSO Implementation — Complete Guide SSO Authentication in ASP.NET Core Web API — Complete Guide Authentication Server using ASP.NET Core Web API — Complete Guide Resource Server using ASP.NET Core Web API — Complete Guide Client Application One using ASP.NET Core MVC — Complete Guide Client Application Two using ASP.NET Core MVC — Complete Guide
Module 14: API Versioning ASP.NET Core Web API Versioning — Complete Guide ASP.NET Core Web API Versioning using Query String — Complete Guide ASP.NET Core Web API Versioning using URL Path — Complete Guide Header Versioning in ASP.NET Core Web API — Complete Guide Media Type Versioning in ASP.NET Core Web API — Complete Guide
Module 15: Repository Pattern Introduction to Repository Pattern in ASP.NET Core Web API — Complete Guide Start Without Using Repository Pattern in ASP.NET Core Web API — Complete Guide Implementing Non-Generic Repository Pattern in ASP.NET Core Web API — Complete Guide Implementing Generic Repository Pattern in ASP.NET Core Web API — Complete Guide Combining Generic and Non-Generic Repositories in ASP.NET Core Web API — Complete Guide Unit of Work with Repository Pattern in ASP.NET Core Web API — Complete Guide
Module 16: E-Commerce Real-Time Application Real-time Ecommerce Application using ASP.NET Core Web API and EF Core — Capstone Customer Module in ECommerce Application — ShopNest.API Address Module in ECommerce Application — ShopNest.API Category Module in ECommerce Application — ShopNest.API Product Module in ECommerce Application — ShopNest.API Shopping Cart Module in ECommerce Application — ShopNest.API Order Module in ECommerce Application — ShopNest.API Payment Module in ECommerce Application — ShopNest.API Cancellation Module in ECommerce Application — ShopNest.API Refund Module in Ecommerce Application — ShopNest.API User Feedback Module in Ecommerce Application — ShopNest.API
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