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Differences Between RESTful and RESTless APIs: Understanding Restful vs Restless API 1

Differences Between RESTful and RESTless APIs: Understanding Restful vs Restless API

The 21st century represents the age of integration. In the era of technological advancement and the digital revolution exchanging data between two or more software systems has become more essential than ever. And API is that connection link facilitating data exchange. 

What is API?

API (technically known as Application Program Interface) functions as a middleman between two software or application databases and enables them to communicate with each other. For instance, cab services such as Uber or food delivery services such as the matter requires location access from Google Maps and payment integration with PayPal, MasterCard, or Visa. 

In recent times, API has gained immense popularity in the market for almost every software system or application. Whether you check the weather or book a cab ticket using a digital device, an API is called at the backend. As API, directly and indirectly, opens up opportunities and ultimately drives business revenue by enabling firms to open their software’s data and functionality to external third-party software products. 


Why is API becoming increasingly important?

The following factors contribute to the immense popularity of API: 

Seamless integration  

Smooth communication between platforms and applications can be established through API integration. Without using API, developers and enterprises had limited connectivity leading to reduced productivity and overall poor performance. Seamless integrations allow smooth data movement, thus empowering businesses to automate processes easily and enhance workplace collaboration. 

Supports automation

Automation boosts API testing, which translates into increased efficiency. API doesn’t just link the digital domain with its dynamic nature, but it also enables enterprises to become more agile by automating workflows.

Security amplification 

Security is a supplemental benefit. API reinforces an additional blanket of protection between your business data and server. However, developers have the option to further strengthen their security by leveraging signatures, tokens, and transport layer security (TLS) encryption.


Efficiency increases with decreasing human or manual intervention. Providing API access prevents content duplication, extending greater flexibility for enterprises to spend time on innovation that matters. 


RESTless and RESTful API

Web services represent client and server applications, which use Hypertext Transfer Protocol (HTTP) to communicate over the WWW. It illustrates the standards for data exchange between different applications or software programs running on different platforms and frameworks. When you forward an HTTP request to a URL with arguments/requirements, the service sends back the result as a response. Furthermore, a web service is platform-independent.

RESTless and RESTful terms are mostly similar to each other and sometimes create confusion. However, they present some substantial differences. But before we start exploring the differences, let’s understand what REST is. REST is an acronym for the technical concept- of REpresentational State Transfer. Introduced by Roy Fielding, the brain behind HTTP (HyperText Transfer Protocol), REST was conceptualized to make the best use of HTTP. It performs actions based on transfer protocols such as HTTP-post, GET, PUT, and DELETE.

REST is also referred to as an Architectural Style for web services. REST embodies the following three elements:

  • Transport (HTTP only)
  • Data exchange format(JSON popularly)
  • Service Definition (WADL/Swagger)

The following principles define the functionality of Rest Services:

  • No involvement of any inbuilt encryption.
  • Devoid of the session and is stateless.
  • Only uses a single protocol, that’s HTTP.
  • It returns anything in the form of JSON.
  • Capable of performing CRUD operations utilizing HyperText Transfer Protocol.


What is a RESTful API?

As mentioned previously, REST stands for Representational State Transfer and is a style of software architecture. The API interfaces following the REST architecture principles are known as RESTful API or web interfaces. Moreover, RESTful services locate the resource by utilizing the URL. It performs activities based on the transport protocol (HTTP –GET, POST, PUT, DELETE).  RESTful APIs are scalable, faster, and support almost every type of data. A RESTful API is the most prevalent category of API used in web development stacks.

Some of the primary elements of RESTful APIs include the following:

  • Headers – Using HTTP headers, RESTful APIs handle various information, including connection types, proxies, and metadata, for request messages and their valid responses.


  • Data – Data represents the body containing additional information on the client-requested resource. After a client specifies the content type in the header, the body entails the actual content.


  • Method – These APIS manipulate data by using certain HTTP methods like DELETE, POST, or GET to support accurate server functions.


  • Endpoints – These URLs define data location on the server. Endpoints basically represent the resources you try to access through an API.

RESTful web services or APIs embody several benefits. They require less bandwidth, support almost every type of data format, have a simple learning curve, and do not require a development from scratch. RESTful APIs are immensely popular in the SaaS application development domain and ideal for both public and private use.


What is a RESTless API or Web Service?

RESTless web service or API does not adhere to the REST principles. It follows SOAP (an acronym for Simple Object Access Protocol). Unlike the RESTful API, the RESTless web service sends an XML request over the net using HTTP protocol and receives an XML response. Thus, SOAP or RESTless API is XML based.

Every application sending SOAP requests contains a WSDL file that entails all the methods available in the web service. It also includes the types of requests and responses. In simple words, the WSDL file articulates the connection between the service and the client. Furthermore, it helps in communicating remote procedure calls to remote objects.

RESTless service is ideal for applications and software programs requiring security. However, it has certain constraints. It is comparatively slow and requires a greater amount of resources and bandwidth.

Why should you use RESTless API?

  • REST modeling presents a lack of schema
  • In certain cases, REST modeling can be unwieldy
  • Binary protocols offer greater efficiency than JSON 

In a microservices realm, the number of services can grow significantly, each exposing multiple APIs. Lack of schema in REST modeling/JSON poses a big integration challenge in such cases. Thus, in such a specific environment, it is always better to maintain a well-defined interface for every call. 


Difference Between Restful and Restless Web Service


RESTful web interface that adheres to the REST architectural style or principles to offer interoperability between software systems on the internet. RESTless API is an interface that is not following the principles of REST. 



RESTful API follows REST. 

RESTless web services utilize SOAP.

Data Format

RESTful API supports several data formats, such as HTML, JSON, text, etc. 

RESTless web services support only XML format.


RESTful API uses URLs to expose business logic.

RESTless API uses the service interface to expose business logic.


RESTful services are easier and more flexible.

RESTless services can be complex and slow.


RESTful is less secure since it inherits security measures from the underlying transport protocols. 

RESTless is comparatively more secure since it defines its own security layer.

Resources and Bandwidth

RESTful API requires less bandwidth and resources.

RESTless API takes up more bandwidth and resources.


Frequently Asked Questions


What is the difference between RESTful API and RESTless web services?

The primary difference between RESTful and RESTless API is that the RESTful web service is an API application that complies with Representational State Transfer architecture, while the RESTless web API service does not follow RESTful principles.


What is REST API vs. SOAP?

REST APIs access a resource for data (a URI), while SOAP APIs execute an operation. REST architecture is more data-driven, while SOAP represents a standardized protocol for structured information transfer that’s more function-driven.


Is RESTful stateless or stateful?

According to the REST architecture standards, a RESTful Web Service should not maintain a client state on the server. This restriction is known as Statelessness. It is the responsibility of the developer to pass its context to the server. Then the server can store this context to process the developer’s further request.


Wrapping Up

The primary difference between RESTful and RESTless API is that the RESTful focuses on applications that follow the Representational State Transfer architecture while the RESTless API is an application that doesn’t follow RESTful principles.

Debaleena Ghosh

Debaleena Ghosh

Debaleena is a freelance technical writer, and her specialty is absorbing several pieces of data and tech info to articulate them into a simple story. She helps small and large tech enterprises communicate their message clearly across multiple products.

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