Web API vs web service: Top 10+ Differences between web API and web service in C#

Web API vs web service: A Web API & Web service are ways for two machines to communicate with each other over a network. They both allow for information to be exchanged between a client and a server.

An API or web service hosted on a machine can receive requests from other devices(such as smartphones, computers, and tablets,) over a network and sends back the requested resources, which can be in various formats like XML, JSON, HTML, images, audio files, etc.

Web APIs and web services look similar but they have some key differences, so it’s important for us to know them before incorporating them into our project.

Web API vs Web Services

Key Differences Between Web API and Web Service in C#

  • Web services and Web APIs are different in how they are built and the format they use to transmit data. Web services are often built using the Simple SOAP (Object Access Protocol) and the data is transmitted over the network using XML (Extensible Markup Language). Web APIs, however, are usually designed using REST(Representational State Transfer) and the data is sent using JSON (JavaScript Object Notation).
  • Another important difference is the purpose of each solution. Web services are frequently used in more complex, enterprise-level applications where security and reliability are critical. Web API, on the other hand, is more focused on providing access to specific functionality or data and is typically lighter and easier to use than web services.

What is an API?

An API (Application Programming Interface) is a set of rules that govern how two software programs written in the same or different programming languages interact with one another.
An API allows one software program to access the functionality of another software program in a standardized way.

APIs are a way for different software to communicate together and share information. Web APIs are very common and can be used by different types of devices such as your phone, computer, and tablet.

Features of Web APIs

The following is the list of features that are commonly found in Web APIs:

  • Web APIs are used for exchanging data between different systems or applications.
  • Web API uses standard protocols such as HTTP/HTTPS to connect and share data.
  • We can use Web API to expose service data to a browser as well.
  • A Web API can be considered a kind of request & response model in which a client sends a request to the API and the API sends a response in return.
  • We can use Web API to perform traditional CRUD operations using HTTP verbs such as GET, PUT, POST, and DELETE.
  • Web API uses Restful architecture that allows us to create a scalable, flexible, and maintainable API.
  • It can be used to expose data and functionality to different clients, such as web, mobile, and desktop applications, as well as other systems and devices.
  • We can secure the Web API by using various authentication and authorization methods, such as OAuth and API keys.
  • We can use Web API to support multiple data formats such as JSON and XML, which provide flexibility to the exchange the data between different devices.

What is a Web Service?

A web service is a way of communication between two devices or systems over a network.
Web services are generally based on a collection of standards and protocols, such as HTTP protocol. It can be used to exchange data between different software applications written in various programming languages which are running on different platforms.
For example, A web service can allow a mobile, desktop, or web-based application to access data from a database or from a legacy system.

Features of Web Services

Here, we have a list of some essential features of web services:

  • Loosely coupled: Web services are designed to be loosely coupled, which means that the client and the service are independent of each other and can be developed and modified separately. This is achieved by using standard protocols (such as HTTP) and interfaces, which allow the client and the service to communicate without the need for them to be tightly integrated. This loose coupling allows for greater flexibility and scalability because it enables the client and the service to evolve independently without affecting each other.
  • Support remote procedure calls: Web services can use special protocols like SOAP or XML-RPC to let one computer (the client) run functions on another computer (the server) as if they were on the same one. This is called remote procedure calls. The client sends a request with the function name and any needed information to the server, the server then performs the function and sends back the result or an error message. This allows different computers to work together and create systems that are spread out. This enables clients to access and execute functions on remote servers over a network, enabling the creation of distributed systems.

Web API vs web service in C#

The following are some key differences between web APIs and web services in C#:

ParameterWeb APIWeb Service
Definition:Web API is a set of rules for accessing a web-based software application or web server.Web Service is a method of communication between two electronic devices over a network
Protocol:It supports REST (representational state transfer) or SOAP (simple object access protocol).It supports SOAP.
Data format:It can be used by the client application that can understand the JSON or XML. It is lightweight compared to Web service.It can be used by the client who can understand XML.
Implementation:Web API is Built on top of the HTTP protocol.Web Service can be built on top of HTTP/HTTPS, but we can also use it with other protocols as well such as SOAP, REST, and XML-RPC.
Purpose:Expose functionality and data to clients over a network.It allows devices to communicate and exchange data.
Use cases:It can be used with Mobile apps, web apps, and other client applicationsLegacy systems integration, integration with other systems and applications, and cross-platform communication.
Specifications:A WEB API is a set of defined rules and specifications that allow for effective communication and interaction.On the other hand, A web service may not have a complete set of specifications and may not be able to perform all functions that can be carried out by a WEB API.
Differentiation:Not all APIs are web services,but all web services are APIs.
Browser:Web API can be assessed through the client browser.Web services can’t be directly accessed through a web browser.
Data compression:Data can be compressed. A web service uses HTML requests that can be compressed. However, XML data cannot be compressed.
Web API vs web service in C#

Disadvantages of Web API

Here, we have a list of some of the disadvantages of using web API:

  • The process of creating an API can be time-consuming.
  • A fixed scale is necessary for the API to function properly.
  • It can be difficult to accurately define the boundaries of an API.
  • We need to have programming knowledge to create an API.
  • The cost of maintaining an API can be high.
  • Testing an API can sometimes cause it to crash.

Disadvantages of Web Services

The following are some of the disadvantages of using web services:

  • We can’t access Web services directly through a web browser.
  • Web API may not take advantage of new web developments like the Semantic Web or AJAX XMLHttpRequest.
  • Some web services can be difficult to use due to flaws in their design.
  • Specialized machine requirements may be needed to support a web service that handles a large number of customers.
  • The HTTP protocol used by many web services is not reliable, which means there is no guarantee that a response will be delivered.

When to Use Web API vs Web Service in C#

We can consider the following factors when deciding whether to choose between a web API or web service for our C# project:

  • The type of data you need to transmit: If you need to transmit complex data structures or require a high level of security, a web service may be the better choice. If you only need to transmit simple data types and are more concerned with ease of use, a web API may be a better fit.
  • The type of application you are building: If you are building an enterprise-level application with a large number of users, a web service may be more suitable due to its robust security and reliability features. If you are building a smaller, more targeted application, a web API may be a more efficient solution.
  • The level of integration required: If you need to integrate with a variety of different systems, a web service may be a better choice due to its ability to handle complex data structures and security requirements. If you only need to integrate with a single system or service, a web API may be sufficient.

How we can create a simple web API in C# .NET?

We can use the following steps to create a simple Web API in C# .NET:

  • Create a new ASP.NET Web API project in Visual Studio.
  • Define your API controllers by creating a new class that derives from the ApiController class and adding methods for each API endpoint you want to expose.
  • Use the [HttpGet], [HttpPost], [HttpPut], and [HttpDelete] attributes to specify the HTTP verb for each method.
  • Add any necessary dependencies and configure your project settings as needed.
  • You can test your API using a tool like Postman or by calling the API from a client application.
Creating a new Web API Project


The following is a sample code to create Web APIs in ASP .NET web applications.

using System.Collections.Generic;
using System.Web.Http;
namespace MyWebApiProject.Controllers
    public class ValuesController : ApiController
        private static readonly List<string> values = new List<string>
            "value1", "value2", "value3", "value4"

        // GET api/values
        public IEnumerable<string> Get()
            return values;

        // GET api/values/5
        public string Get(int id)
            return values[id];

        // POST api/values
        public void Post([FromBody]string value)

        // PUT api/values/5
        public void Put(int id, [FromBody]string value)
            values[id] = value;

        // DELETE api/values/5
        public void Delete(int id)

In the above example, We have defined a simple API that allows clients to retrieve, add, update, and delete values from a list. The [HttpGet], [HttpPost], [HttpPut], and [HttpDelete] attributes specify the HTTP verb that each method will handle.

In the following image, we can see how we have called a Web API [HttpGet] method using the browser.

Output: Calling web API using a browser.


The following are some frequently asked questions and answer related to Web API and Web services:

Q: Is web service a RESTful or API?

In short, a web service can be either RESTful or an API, but not all web services are RESTful, and not all APIs are web services.

Q: Why web API is called REST?

A web API that is built using the REST architectural style is called a RESTful API. REST stands for Representational State Transfer and is an architectural style for building web services. The RESTful APIs are designed to be easy to use and to expose resources that can be accessed over the internet using the HTTP protocol.

Q: Why REST is called stateless?

REST is called stateless because the server does not maintain any state information about the client sessions. In a RESTful architecture, the server responds to each request from the client with the appropriate data, and it does not store any information about past requests or the state of the client.
Therefore, REST applications require each request to contain all required information within the request itself for the server to understand it.

Q: What is REST vs SOAP?

REST and SOAP are protocols for accessing web services. REST is a lightweight protocol that is designed to be simple and flexible, on the other hand, SOAP is a more rigid protocol that is designed to be extensible and secure. REST is generally easier to use and more widely supported, while SOAP is more powerful and secure but also more complex.

References: JavaTpoint-Web Services VS Web API

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17 days ago

The explanation and the Diagram was very helpful and gave a great understanding about the Web API and Web Services.