If you’ve started working with web development or APIs, you’ve likely heard terms like REST API and RESTful API used interchangeably. While they may sound similar, they aren’t exactly the same. In this blog, we’ll explore the difference between REST and RESTful APIs in a way that’s easy to understand—even if you’re just getting started with API architecture.
A REST API stands for Representational State Transfer API. It follows a set of principles that help systems communicate over HTTP using standard methods like GET, POST, PUT, and DELETE. Many developers refer to any API that uses HTTP as a REST API, but that’s not always accurate. On the other hand, a RESTful API is one that fully follows the REST design principles, including statelessness, resource-based URIs, and proper use of HTTP methods.
Understanding RESTful API design principles helps you write better, more scalable code. When you follow the RESTful approach, your API becomes more predictable, easier to maintain, and faster to develop. You can also improve performance by using stateless protocols and clear endpoint structures. That’s why many developers and companies prefer RESTful architecture over a loosely defined REST API.
In this post, we’ll break down REST vs RESTful concepts, highlight key REST API vs RESTful API differences, and help you decide which one works best for your project. Whether you’re building your first API or improving an existing one, this guide will clear up the confusion and give you a strong foundation in modern web API development.
A REST API (Representational State Transfer Application Programming Interface) lets different software systems talk to each other using standard web methods. It allows web browsers, mobile apps, or any client to connect with servers over the internet—usually through the HTTP protocol.
Roy Fielding introduced the concept of REST in his 2000 doctoral dissertation. Instead of inventing a new communication method, REST uses the existing structure of the web. It relies on familiar and simple ways to send and receive data between systems.
Developers use REST APIs to handle tasks like getting user data, adding new records, updating existing information, or removing resources from a system. These operations follow clear and consistent patterns, which makes REST APIs easy to understand, implement, and maintain.
The Six Core Principles of REST API
To build a RESTful API, developers should follow six key REST API design principles. These principles help make the system more scalable, flexible, and easier to maintain.
A REST API separates the system into two main parts: the client and the server.
This separation allows both the client and server to evolve independently. It also improves flexibility and simplifies updates.
In a RESTful API, each request from the client must include all the information the server needs to understand and process it. The server does not store any session data about previous requests. This stateless nature makes the system more scalable and easier to manage.
A REST API can mark responses as cacheable or non-cacheable. When a response is cacheable, the client can temporarily store it and reuse it for similar requests. This reduces server load and improves performance.
You can design a RESTful API with multiple layers between the client and the server, such as proxies, load balancers, or security filters. Each layer works independently. The client doesn’t need to know how many layers exist or what they do. This design improves both security and scalability.
One of the most important REST API principles is a consistent way of communication.
This uniform approach makes APIs easier to learn, use, and maintain.
In some cases, the RESTful API can send executable code (like JavaScript) to the client. This allows the client to add new features without needing a full update. Although this principle is optional and not widely used, it offers added flexibility when needed.
Read also: How To Use An API with Java
A RESTful API is a more advanced and complete form of a REST API. While a REST API allows clients and servers to communicate over the web using standard HTTP methods, a RESTful API follows all six key REST principles. It doesn’t just send and receive data—it also guides users on what they can do next through something called HATEOAS (Hypermedia as the Engine of Application State). This feature makes the API more interactive, self-explanatory, and flexible.
A RESTful API follows the architectural style defined by Roy Fielding and fully commits to REST’s six core constraints: client-server architecture, statelessness, cacheability, a uniform interface, a layered system, and optional code on demand. What sets it apart is its focus on a consistent structure and HATEOAS, which allows APIs to include links in responses that show clients the next available actions—like viewing related data or performing another operation.
A RESTful API doesn’t take shortcuts. It applies every REST constraint to ensure smooth, secure, and scalable communication between clients and servers. This consistency helps developers create robust and future-proof applications.
HATEOAS is what truly defines a RESTful API. It adds useful links in each response, helping clients understand what they can do next—like viewing an order, editing a profile, or deleting an account. These hypermedia links remove the need to hard-code URLs, making the API easier to explore and adapt.
Thanks to HATEOAS, clients can explore the API step by step, just like navigating a website. This dynamic nature reduces reliance on external documentation and allows your applications to adapt as your API evolves.
Every API response includes helpful metadata, such as HTTP status codes and headers, so developers always know what the response means. This clear communication improves debugging, testing, and user experience.
Many developers use REST API and RESTful API as if they mean the same thing—but they don’t. Both follow the REST architectural style introduced by Roy Fielding, but the way they apply it makes a big difference. A REST API loosely follows REST principles and focuses mainly on using HTTP to manage resources. A RESTful API, on the other hand, fully follows all REST constraints, including the often-overlooked HATEOAS (Hypermedia as the Engine of Application State).
The main difference between REST and RESTful APIs lies in how strictly they follow REST principles. REST defines six key rules: client-server architecture, statelessness, cacheability, a layered system, a uniform interface, and optionally, code-on-demand.
A REST API might follow just a few—usually the basics like client-server and statelessness. But a RESTful API follows all six. It emphasizes a uniform interface and includes HATEOAS, which makes the API more intuitive and easier to expand over time.
RESTful APIs improve discoverability by guiding the client with helpful links. For example, when your app requests a user profile, a RESTful API might also send links to edit or delete the profile or view the user’s orders. This approach reduces the need for hardcoded endpoints and helps clients navigate the API more easily. In contrast, REST APIs expect the client to already know all the URLs and how to structure each request.
In REST APIs, you might see URLs like /getUserData or /createOrder, which include action verbs. That breaks REST rules. RESTful APIs avoid this. They use resource-based URIs like /users/123 or /orders/456 and rely on HTTP methods (GET, POST, PUT, DELETE) to show what action to take. This keeps the API clean, logical, and easy to maintain.
RESTful APIs also return more than just raw data. They include helpful context—like HTTP status codes, headers, and links—to explain what the response means and what you can do next. This is called a self-descriptive message. In contrast, REST APIs usually just return the requested data without much explanation, which can make it harder for clients to figure out what comes next.
You can use REST APIs for smaller apps or internal systems where speed and simplicity matter most. They’re quicker to build and work well when you don’t need a lot of flexibility. But when you’re building a public API or a large platform that needs to scale and evolve over time, a RESTful API is a better choice. Its hypermedia-driven design makes it easier to expand, maintain, and future-proof your app.
Many developers use the terms REST API and RESTful API as if they mean the same thing, but they have subtle differences. Here’s a simple way to decide when to use each term, based on your project’s needs.
Use a REST API when your project is simple and doesn’t need the full structure of a RESTful API. For example, if you’re building an internal tool or a small app where you control both the client and server, a REST API is usually enough. It’s easier to build and requires less planning.
You can also choose a REST API when you need to launch your project quickly. Since REST APIs don’t always follow strict RESTful design principles, they allow faster development without added complexity.
If your endpoints rarely change, or if your API has a stable structure, a REST API works well. You won’t need advanced features like dynamic discovery or hypermedia navigation.
Lastly, when you manage both sides of communication—such as a mobile app and its backend—you can hardcode your API endpoints. In this case, you don’t need the flexibility and self-discovering nature of a RESTful API.
Choose a RESTful API when your application interacts with third-party clients or needs to scale over time. A RESTful architecture makes your API easier to use, especially when different teams or apps need to integrate with it.
RESTful APIs are a great choice for large, complex systems. They offer more flexibility, follow clear design rules, and make it easier to manage updates without breaking existing clients.
If you expect to grow your API or change its features regularly, a RESTful API keeps your system future-ready. Clients can use hypermedia links (HATEOAS) to discover new resources and actions dynamically, without relying on hardcoded URLs.
Also, if your clients need rich, flexible interactions—like exploring related resources or navigating different actions—RESTful APIs provide built-in guidance through hypermedia, improving the overall developer and user experience.
Understanding the difference between a REST API and a RESTful API goes beyond just knowing the terms—it helps you design better APIs. While every RESTful API is a REST API, not all REST APIs follow the full set of RESTful design principles. A basic REST API might use HTTP methods and resource-based URLs, but a fully RESTful API also follows all six REST constraints, including important rules like HATEOAS (Hypermedia as the Engine of Application State).
As a full-stack developer, you should choose the right approach based on your project’s goals. If you want something quick and simple, a basic REST API might work well. But if you’re building a large, scalable system that needs to grow over time, a RESTful API offers better structure, flexibility, and self-descriptive communication. If you want expert help, you can hire API developer India teams to build reliable and efficient solutions customized to your needs.
No matter which option you choose, focus on clear API design and consistent implementation. That way, you’ll create a better experience for both your team and your users.
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