Decoding the Web: Unraveling the GraphQL vs. REST Comparison

ByBalogopal Sharma

January 30th . 6 min read

Unraveling the GraphQL vs. REST Comparison

GraphQL and REST are common architectural patterns for building APIs. GraphQL is touted as an alternative to REST APIs. In this article, we will review about GraphQL and REST.

What Is GraphQL?

GraphQL is a query language for APIs that enables declarative data fetching to give the client the power to specify exactly the data that is needed from the API. GraphQL was developed internally by Facebook in 2012 and later, publicly released it as open source. Since then, the software development community has utilized it as one of the favourite technology stacks for developing web services. GraphQL enables you to perform three operation types: queries, mutations, and subscriptions.

Queries: Fetch data with the help of queries. Query is a GraphQL Operation that allows you to fetch specific data from the server.
Mutations: Mutations allow the client to mutate data on the server. It allows you to insert new data or modify the existing data on the server-side.
Subscriptions: Subscriptions are useful for notifying your client in real time about changes such as the creation of a new object or updates to an important field.

What Is RESTful API?

A RESTful (Representational State Transfer) API is an architectural style for designing networked applications. It's based on a set of principles that describe how web standards such as HTTP, URLs, and JSON (or XML) are used for creating, updating, reading, and deleting resources.

Key Principles of a RESTful API:

Client-server architecture: Separation between the client and server, allowing them to evolve independently. Clients interact with the server through standardized requests.
Stateless: Each request from the client to the server must contain all necessary information to fulfill that request. The server doesn't store the client's state between requests.

Resource-Based: Resources (such as users, articles, or products) are identified by unique URIs (Uniform Resource Identifiers), and the API interacts with these resources using various HTTP methods.
Representation of Resources: Resources are represented in a specific format (like JSON or XML), and the server provides these representations to the client based on the client's request headers.
Uniform interface: The API has a uniform and standardized interface, typically using HTTP methods (GET, POST, PUT, DELETE) to perform CRUD operations on resources.

GraphQL vs REST: An Example

If you have an API to fetch a user's profile and their address. In REST, the request/response would look like:

The core of REST API revolves around resources. Resources are identified by URLs and request type (GET, POST, PUT, DELETE etc.).

If your API server was a GraphQL server instead, then your API calls would look like:

The response JSON is different for different "queries" sent by the client.

Request1:         | Response1:
 
query {           |  {
  user (id: 1) {  |    "user": {
    id            |       "id": 1
  }               |     }
}                 |  }
 
----------------------------------------
 
Request2:         |   Response2:
 
query {           |   {
  user (id: 1) {  |     "user": {
    id            |       "id": 1
    name          |       "name": "Elmo"
  }               |     }
}                 |   }

GraphQL benefits

Avoid over-fetching: You avoid fetching more data than you need because you can specify the exact fields that the client requested.
Prevent multiple API calls: If you need more data, you can also avoid making multiple calls to your API. In the case above, you don't need to make two API calls to fetch user and address separately.
Better Handling of Complex Systems and Microservices: GraphQL can unify and hide the complexity of integrated multiple systems. If we want to migrate from a monolithic backend application to a microservice architecture, then GraphQL API helps to handle communication between various microservices by merging them into one GraphQL schema.
Fast and Secure: GraphQL’s ability to avoid over fetching and under fetching, the backend server returns a secure, easy-to-read, and predictable shape which makes your API requests and responses faster.

Schema and Type System

GraphQL schemas are often defined using SDL, a declarative syntax for defining types, queries, mutations, etc. The schema in GraphQL serves as a fundamental agreement or contract between the server and the client to define how a client can access the data. A schema example:

type User {
  name: String!
  age: Int
  posts: [Post!]!
}

type Post {
  title: String!
  subtitle: String!
  body: String!
  date: String!
  author: User!
}

type Query {
  users: [User!]!
  user(name: String!): User!
  posts: [Post!]!
  post(title: String!): Post!
}

type Mutation {
  createUser(name: String!, age: Int): User!
  createPost(title: String!, subtitle: String!, body: String!): Post!
}

Drawbacks of GraphQL

While GraphQL offers several advantages, it's essential to consider its drawbacks and limitations when deciding whether to use it for a project:

Complexity & Learning Curve: GraphQL introduces a different way of fetching data compared to REST, requiring developers to learn a new query language and its nuances. Implementing GraphQL might add complexity to the server-side code, especially in scenarios involving complex data structures or real-time functionalities.
File Uploading: GraphQL does not support native file upload feature. We need to install graphql-upload package for file uploads via queries and mutations.
Web Caching: Caching strategies might be more complex due to the nature of GraphQL responses being tailored to each query. Effective caching requires careful consideration and implementation.
Over-engineering: For simpler applications or scenarios where the flexibility of GraphQL is not necessary, using GraphQL might lead to over-engineering.
Performance Tuning: Optimizing GraphQL queries for performance can be challenging, especially with complex data retrieval scenarios. Improperly constructed queries might put a higher load on the server, impacting performance.

Drawbacks of REST

While REST has been a prevalent architectural style for designing APIs, it also comes with its set of limitations and drawbacks:

Statelessness Limitations: Stateless nature might pose challenges in managing sessions and maintaining context, especially in scenarios requiring server-side state.
Over-fetching and Under-fetching: REST endpoints might return more data than needed for a particular client's requirement, leading to unnecessary data transfer. In scenarios where clients need additional related data, multiple requests or custom endpoints might be required, leading to increased roundtrips.
Discoverability Issues: Discovering available endpoints and their functionalities might be challenging without proper documentation, leading to difficulties for developers integrating with the API.

GraphQL vs REST Showdown Lastly, we are going to explore the major difference between GraphQL and RESTful APIs.

Conclusion

Both GraphQL and REST API development lifecycle approaches are useful depending on the need, and both have their benefits and drawbacks. Both GraphQL and REST have their strengths and are suitable for different use cases. The choice depends on specific project requirements, data structures, client needs, and trade-offs in complexity, efficiency, and ease of implementation. Some projects might even use a combination of both to leverage their respective strengths in different parts of the application.

Happy Coding!