GraphQL vs. REST: unraveling the differences
Representational State Transfer (REST) and GraphQL are two of the most widely used architectural paradigms for creating Web APIs. While GraphQL is a query language that lets clients specify the format of responses for their queries and modifications, offering a more flexible approach to data interaction, REST APIs operate on data using normal HTTP methods like GET, POST, PUT, and DELETE.
The core difference between GraphQL and REST APIs is that GraphQL is a specification, a query language, while REST is an architectural concept for network-based software.
Both serve the purpose of enabling communication between clients and servers, but they do so in fundamentally different ways. In this blog post, we’ll explore what RESTful APIs and GraphQL APIs are, how they differ, what similarities they share, and ultimately, which one might be the better choice for your project.
Understanding RESTful APIs
REST (Representational State Transfer) is an architectural style that conforms to a set of constraints when developing web services. It was introduced as a successor to SOAP APIs. REST, or RESTful APs, are Web Service APIs that follow the REST standards. Unlike SOAP, a REST API is not constrained to an XML format and can return multiple data formats depending on what is needed. The data formats supported by REST API include JSON, XML, and YAML.
REST is an architectural style for designing networked applications. RESTful APIs are built on top of HTTP, adhering to its principles of statelessness and uniform resource identifiers (URIs). Key characteristics of REST include:
Layered System architecture
REST API requests and responses are routed through many tiers. REST APIs must be designed so neither the client nor the server can tell whether they communicate with the final application or an intermediary.
Client-Server Architecture
RESTful APIs are built with a client-server architecture, meaning that the client sends a request to the server and the server sends back a response. The client can be any device or application that can make HTTP requests, while the server is the application that provides the API and responds to client requests. This characteristic allows for the separation of concerns, making it easier to develop, maintain, and scale both of these components independently.
Statelessness
REST APIs are stateless, meaning that each request needs to include all the information necessary for processing it. In other words, REST APIs do not require any server-side sessions. Server applications aren’t allowed to store any data related to a client request. There is no session state stored on the server between requests.
Caching REST API Response
Caching is the ability to store copies of frequently accessed data in several places along the request-response path. When a consumer requests a resource representation, the request goes through a cache or a series of caches toward the service hosting the resource.
Working with REST APIs:
A REST request is made up of the endpoint, HTTP method, Header, and Body.
An endpoint contains a URI (Uniform Resource Identifier) that helps in identifying the resource online.
An HTTP method describes the type of request that is sent to the server. They are:
- GET reads a representation of a specified source.
- POST creates a new specified source.
- PUT updates/replaces every resource in a collection.
- PATCH modifies a source.
- DELETE deletes a source.
When working with data, a RESTful API uses HTTP methods to perform CRUD (Create, Read, Update and Delete) operations
REST Request:
For the RESTful API, you’d need separate endpoints for different data.
GET Request to /books to get all books.
{
“books”: [
{
“title”: “Book 1”,
“author”: “Author 1”,
“publishedYear”: 2000
},
{
“title”: “Book 2”,
“author”: “Author 2”,
“publishedYear”: 2005
}
]
}
GET Request to /books/Harry%20Potter to get details of the book with the title “Harry Potter”.
/books/Harry%20Potter
// GET /books/Harry%20Potter
{
“title”: “Harry Potter”,
“author”: “J.K. Rowling”,
“publishedYear”: 1997
}
Introducing GraphQL APIs:
GraphQL is an open-source specification that offers an alternative viewpoint on API design. GraphQL retrieves current data using queries and modifies data using mutations utilizing a single endpoint, as opposed to working with numerous, inflexible server-defined endpoints. GraphQL is a straightforward query language that allows the client to specify the information the server should return in response.
Another important feature of GraphQL APIs over traditional RESTful APIs is that they are tightly typed. Before performing queries, modifications, and subscriptions, the GraphQL server verifies and enforces their structure against the GraphQL Schema.Key characteristics of GraphQL include:
1. Flexible Queries
With GraphQL, clients can request exactly the data they need, no more and no less. Clients define their data requirements in the query itself, which reduces over-fetching and under-fetching of data.
2. Single Endpoint
Unlike REST, GraphQL APIs have a single endpoint for all requests, often /graphql. This simplifies the API’s structure and makes it easy for clients to request related data in a single query.
3. Strong Typing
GraphQL APIs are strongly typed. You define a schema for your data, including types, queries, and mutations. This schema serves as documentation and enables auto-completion and validation in GraphQL clients.
4. Real-time Data
GraphQL supports real-time data with subscriptions, allowing clients to subscribe to changes and receive updates when data changes on the server.
GraphQL Schema:
type Book {
title: String
author: String
publishedYear: Int
}
type Query {
books: [Book]
book(title: String!): Book
}
GraphQL Query:
With GraphQL, clients can request only the data they need in a single request.
query {
books {
title
author
}
book(title: “Harry Potter”) {
title
author
publishedYear
}
}
GraphQL Response:
{
“data”: {
“books”: [
{
“title”: “Book 1”,
“author”: “Author 1”
},
{
“title”: “Book 2”,
“author”: “Author 2”
}
],
“book”: {
“title”: “Harry Potter”,
“author”: “J.K. Rowling”,
“publishedYear”: 1997
}
}
}
Key Differences Between REST and GraphQL
Now that we understand the basics, let’s delve into the key differences between REST and GraphQL:
1. Over-fetching and Under-fetching
REST responses are known for either containing too much data(retrieving more data than needed) or not enough of it(not retrieving enough data), creating the need for another request. GraphQL solves this efficiency problem by fetching the exact data in a single request. because clients have no control over the server’s response. GraphQL eliminates these issues by letting clients specify their exact data requirements.
2. Multiple Requests vs. Single Request
In REST, clients typically need to make multiple requests to different endpoints to fetch related data. In GraphQL, clients can get all the related data they need in a single query.
3. Versioning
REST often requires versioning of APIs when changes are made to the structure or behavior. GraphQL’s strongly typed schema and query flexibility make versioning less necessary.
4. Caching
Caching in REST can be complex because resources may have different lifecycles. GraphQL simplifies caching because the shape of the data can be defined by the client.
Common Ground Between REST and GraphQL
Despite their differences, REST and GraphQL do share some similarities:
1. HTTP-Based
Both REST and GraphQL use HTTP as their transport protocol, making them accessible over standard web technologies.
2. Documentation
Both paradigms encourage the creation of clear, well-documented APIs. REST typically uses tools like Swagger, while GraphQL relies on the schema definition.
3. Authentication and Authorization
Authentication and authorization mechanisms can be applied to both RESTful and GraphQL APIs to secure data access.