GraphQL API vs REST API: Understanding the Differences

There are significant differences between GraphQL and REST when it comes to building APIs, and understanding these distinctions can help determine which approach is best for your specific use case.

REST as a Concept

REST (Representational State Transfer) has become the de-facto architecture standard for building APIs. However, REST does not have a formal specification and has multiple unofficial definitions. On the other hand, GraphQL has a comprehensive specification and operates as a Query Language with a well-defined set of tools and a thriving ecosystem.

REST is built on top of existing architectures, typically using HTTP as the foundation. In contrast, GraphQL is designed to establish its own conventions. This can be advantageous or disadvantageous depending on the scenario, as REST inherently benefits from caching at the HTTP layer.

Single Endpoint vs Multiple Endpoints

One of the key distinctions between GraphQL and REST is the number of endpoints. GraphQL relies on a single endpoint for all queries, whereas REST typically involves multiple endpoints with HTTP verbs (GET, POST, PUT, DELETE) used to differentiate between read and write actions. GraphQL, on the other hand, does not use HTTP verbs to determine the request type.

Customized Responses

In REST, the server determines the response returned to the client, and it is challenging to enforce filtering or partial responses unless the server implements sparse fieldsets and clients utilize that feature. This can result in API responses containing more information than necessary, unless the API server is under your control and you tailor responses for each request.

In comparison, GraphQL allows clients to explicitly specify the information they need. Instead of opting out of the full response, clients choose which fields to include. This helps save server resources and reduces network overhead by transmitting smaller payloads.

For example, let’s consider a Pizza endpoint. With REST, you would need separate endpoints for each specific flavor of pizza. However, with GraphQL, you can call a single endpoint (/pizza) and request specific ingredients to build your desired pizza.

Monitoring Field Usage

Determining if a field is needed by the client is often challenging with REST. This makes it difficult to refactor or deprecate certain fields since there is no way to determine their actual usage. GraphQL, on the other hand, enables the tracking of field usage by clients, making it easier to identify and address unused fields.

Accessing Nested Data Resources

GraphQL can significantly reduce the number of network calls required to access nested data. For example, if you need to retrieve the names of a person’s friends, a REST API would typically require multiple requests to obtain both the person’s information and their friends’ names. In contrast, a GraphQL query can retrieve all necessary data with a single request.

Types

While REST APIs rely on JSON, which does not provide type control, GraphQL includes a comprehensive Type System. This enables more precise data validation and control over the structure of API responses.

Choosing the Right Approach

When deciding between GraphQL and REST, it is essential to consider your specific needs. GraphQL excels when it comes to exposing complex data representations and when clients require only a subset of the available data or regularly perform nested queries. However, there is no definitive winner, and the choice ultimately depends on your requirements.

Also, it’s worth noting that you can use both GraphQL and REST together. Depending on the situation, mixing and matching these approaches can provide the best solution.

Tags: GraphQL, REST, API, Query Language, HTTP, Endpoints