What’s the difference between RESTful APIs and GraphQL APIs?

 1. Data Fetching

• RESTful API:
  You get data at many locations (e.g. /users, /users/1/posts). All the endpoints present a predetermined data structure.
  – In many cases, this leads to over-fetching (too much data) or under-fetching (too little data).
• GraphQL API:
  A single endpoint (typically /graphql) is used to access all the data. In the query, you give the precise data that you require.
  – Avoids under-fishing and over-fishing.

 2. Structure & Querying

• REST:
  Supports the HTTP methods (GET, POST, PUT, delete) of various operations.

Every resource (user, product, and so on) is described as a particular endpoint.

• GraphQL:
  A query language is used to request data and mutate (write data).

The query structure is the same as the response is and hence more predictable.

 3. Performance

• REST:
  May require multiple requests to gather related data.
  Example: To get user info + their posts + comments, you might call 3 endpoints.

• GraphQL:
  Is capable of retrieving all associated data on a single request minimizing network requests.

 4. Versioning

• REST:
  Often needs new versions (e.g., /api/v1/, /api/v2/) when data changes.

• GraphQL:
  The no versioning meant that the clients simply asked whether there were new or old fields as required.

5. Tooling & Flexibility

• REST:
  Simpler to set up; widely supported by browsers and frameworks.
  Best for simple, well-defined resources.

• GraphQL:
  More flexible but requires a GraphQL server setup.
  Great for complex systems and microservices where clients need control over the data shape.

Example

REST:
GET /user/1

{

  “id”: 1,

  “name”: “John”,

  “email”: “[email protected]”,

  “posts”: […]

}

GraphQL:

query {

  user(id: 1) {

    name

    email

  }

}

Response:

{

  “data”: {

    “user”: {

      “name”: “John”,

      “email”: “[email protected]”

    }

  }

}