REST vs GraphQL

REST and GraphQL are technologies used to consume APIS. However, each one has their own particularity. This text aims to compare each one of them and provide a short introduction to GraphQL.

GraphQL
It is a query language for API, according to your specification. It was developed by Facebook Team to fix problems found in the REST API.

The principles of GraphQL are:

• You receive what you ask for.

Data is returned from the same fields that you request by the GraphQL query, for example:

Query example:

query {
  city{
    name
  }
}

Query return:

{
  "data": {
    "city": [
      {
        "name": "jundiaí"
      },
      {
        "name": "campinas"
      }
    ]
  }
}

Data is returned from the same fields that you request by the GraphQL query, for example:

const data = {
    city: [
      { id: '1', name: 'jundiaí', state: 'SP' },
      { id: '2', name: 'campinas', state: 'SP' },
    ],
  }

The objects have the fields "state" and "id", but if we don't request them in our query, the API will not return them

• You need only one request.

Unlike REST where we need to request with numerous endpoints, in GraphQL only have to do one request.

REST vs GraphQL

Over-fetching: it's very common to request using the REST API and getting too much unnecessary data and fields returned to us. As we saw, this doesn't happen with a GraphQL query.

Under-fetching: we can request from the REST API, but your response may not return the data you need, and because of that, another request to a different endpoint must be made.

Finally, GraphQL has one endpoint. This is a big advantage because REST uses too many endpoints which may be confusing.