If you are a web developer, you probably have heard of RESTful and GraphQL APIs. But what are they and how do they differ? In this article, we will compare and contrast these two popular approaches to building and consuming web services.
RESTful API stands for Representational State Transfer, a design principle that defines how web resources are identified, accessed, and manipulated. A RESTful API follows a set of rules, such as using HTTP methods (GET, POST, PUT, DELETE) to perform operations, using URLs to specify resources, and using JSON or XML to exchange data. A RESTful API is stateless, meaning that each request contains all the information needed to process it, and does not rely on any server-side session or context.
A REST API is an architectural concept for application communication. On the other hand, GraphQL is a specification, an API query language, and a set of tools. GraphQL operates over a single endpoint using HTTP. In addition, REST development has been more focused on making new APIs. Meanwhile, GraphQL’s focus has been on API performance and flexibility.
GraphQL API stands for Graph Query Language, a query language and runtime system that allows clients to specify the data they need from a server. A GraphQL API exposes a single endpoint that accepts queries and mutations, and returns a response that matches the requested shape and format. A GraphQL API is schema-based, meaning that the server defines the types and fields of the data available, and validates and executes the queries according to the schema.
As a story I would put it this way.. Instead of going to the kitchen to ask for a specific dish, you have a menu (the API) where you can request exactly what you want to eat. You can ask for a burger with specific toppings, or a salad with certain ingredients. With a regular API, it's like ordering a fixed meal from the menu. You get what's on the menu, no more, no less. But with a GraphQL API, it's like being able to customize your order. You can ask for specific pieces of data, in the exact format you want. So if you want a burger, you can ask for just the patty, or if you want a salad, you can ask for only the lettuce and tomatoes.
One of the key differences between RESTful and GraphQL APIs is the level of flexibility and control they offer to the clients. With a RESTful API, the client has to make multiple requests to different endpoints to fetch the data it needs, and may receive more or less data than it wants. With a GraphQL API, the client can make a single request to the same endpoint with a specific query, and get exactly the data it needs, no more, no less. This can reduce the amount of network traffic, bandwidth, and latency, and improve the performance and user experience.
Another key difference between RESTful and GraphQL APIs is the way they handle caching and versioning. With a RESTful API, the client can use HTTP caching mechanisms to store and reuse the responses from the server, and use URL parameters or headers to specify the version of the API it wants to use. With a GraphQL API, the client cannot rely on HTTP caching, since the same endpoint can return different responses depending on the query, and has to implement its own caching logic or use a third-party library. Also, a GraphQL API does not need versioning, since it can add new types and fields to the schema without breaking existing queries, and deprecate old ones gradually.
Both RESTful and GraphQL APIs have their advantages and disadvantages, depending on the use case and the requirements. For RESTful APIs, some of the pros include being simple and standardized, easy to understand and implement, compatible with HTTP tools and libraries, and supporting caching and versioning. However, there are also cons such as being less flexible and efficient, requiring multiple requests and endpoints, potentially overfetching or underfetching data, and needing frequent updates and documentation. On the other hand, GraphQL APIs have pros such as being flexible and efficient, allowing clients to specify and fetch the data they need, reducing network requests and data transfer, supporting schema validation and introspection, and avoiding versioning and breaking changes. Yet there are cons such as being complex and non-standardized, requiring more learning and tooling, not supporting HTTP caching, potentially increasing server load and complexity, and potentially exposing too much data and logic.
There is no definitive answer to which one is better or worse, as both RESTful and GraphQL APIs have their strengths and weaknesses, and can coexist and complement each other. The choice depends on factors such as the type and size of the data, the number and diversity of the clients, the frequency and complexity of the queries, the scalability and maintainability of the server, and the trade-offs and preferences of the developers. The best way to decide is to evaluate the needs and goals of the project, and experiment with both options to see which one works best for you.
In my experience, the best API design architecture depends on your specific use case and goals. You can try both approaches and see which one suits your needs better. You can also use a hybrid approach that combines both RESTful and GraphQL APIs for different parts of your application.