GraphQL vs REST

We can only compare GraphQL with REST by talking about APIs first. The Application Programming Interface (API) is the building block of modern network-based apps. Whether you build web or native apps, microservices, or IoT solutions, in all cases, we need to exchange data between software systems through APIs. On top of that, the rising adoption of hybrid cloud has resulted in data stored in warehouses, lakes, and lakehouses, sometimes across different clouds and on-premises environments. APIs serve as the essential connector between data sources and applications.

When designing an API for the web, terms like GraphQL, REST, SOAP, and rPC come up. So, how can teams decide which architectural style or protocol they should use in their API development? While all named approaches have their place, in this article, we only focus on GraphQL vs. REST. Let's dive in!

GraphQL vs. REST: An introduction to REST

REST (Representational State Transfer) is a popular architectural style for building web services or APIs. It was first introduced in a dissertation by Roy Fielding, in which he writes that REST emphasizes the scalability of component interactions and the generality of interfaces.

Principles and constraints a RESTful API must satisfy:

• Decoupling: Service requesters, called clients (frontend), and service providers, called servers (backend), can only communicate through endpoints.
• Uniformity: Endpoints should have the same interface across devices to foster reusability and encourage independent evolvability of components.
• Statelessness: No session state is allowed on the server component to improve reliability and scalability. Each client-side request must contain all information necessary to serve it.
• Idempotency: A request can be performed multiple times without changing the result beyond the initial application.

RESTful APIs are typically lightweight, scalable, and fast, making them ideal for creating a wide range of web and mobile applications. REST APIs use HTTP methods such as GET, POST, PUT, and DELETE to perform operations on resources that typically return a fixed data structure.

As REST is not a standard, thousands of developers have different interpretations of what REST means. And that is part of the problem. There are lots of differently structured REST APIs out there.

Working with REST APIs

In REST, a request consists of an HTTP request method performed on a resource, represented by a Uniform Resource Identifier (URI). The four primary functions, Create, Read, Update, and Delete (CRUD), are performed using the following HTTP verbs:

• HTTP POST (Create): Submit an entity through the POST request body primarily to create a resource on the server.
• HTTP GET (Read): Request a representation of a resource through its specific endpoint.
• HTTP PATCH (Update): Apply partial modifications to a resource through a resource-specific endpoint.
• HTTP DELETE (Delete): Delete a resource through a resource-specific endpoint.

Many API developers use the HTTP PUT method to partially update resources, although the recommended use is to replace an existing resource with the request payload.

As part of the request, the client and the server can pass additional information with API requests or responses through so-called HTTP Headers. Check out Mozilla's developer documentation for more information on HTTP Headers

GraphQL vs. REST: An introduction to GraphQL

GraphQL, an open source specification, is a new approach to thinking about APIs. Instead of working with multiple and very rigid server-defined endpoints, GraphQL works with a single endpoint to retrieve existing data using queries and modify data using mutations. With GraphQL, the client side defines which fields the server should respond with through its intuitive query language.

Being strongly typed is another critical advantage GraphQL APIs have over classical RESTful APIs. The GraphQL server validates and enforces the structure of queries, mutations, and subscriptions against the GraphQL Schema before executing them.

The type system to define a GraphQL schema consists of the following:

• Object types
• Object fields
• The query, mutation, and subscription root types
• Enumeration types
• Interfaces
• Input types
• Union types

GraphQL queries are the equivalent of HTTP GET requests in a REST API. GraphQL mutations are the equivalent of HTTP POST, PUT, PATCH, and DELETE requests in a REST API. Like REST APIs, the clients and servers can pass additional information through the HTTP headers. Additionally, a GraphQL API developer can use subscriptions to get real-time updates from the server.

To get into the details of GraphQL, head over to our post What is GraphQL?

GraphQL vs. REST comparison

First, GraphQL and REST APIs both involve sending HTTP requests and receiving results, typically formatted in JSON, and GraphQL has many built-in elements of the REST model. However, the core difference between GraphQL and REST APIs is that GraphQL (Graph Query Language) allows sending queries or mutations through a single endpoint compared to resource-specific endpoints in REST APIs.

In REST, the endpoints (resources) define the structure of the API, and the validation of data inputs depends on the diligence of the developers implementing the server-side functionality. Also, what the REST API responds with is entirely up to the creativity of the API developer. Therefore, when consumers of a RESTful API call an endpoint that returns a resource, they rely on complete documentation or a lot of trial and error. The OpenAPI initiative helps to remove the guesswork in calling RESTful web services with its OpenAPI specification.

In contrast, being strongly typed, GraphQL can be validated against a schema defined in the language-agnostic GraphQL schema language. Furthermore, it allows the client to request the data it needs, and the server returns only that data. Therefore there is a lot less over- or under-fetching going on, which enables more flexibility and a more efficient data transfer.

GraphQL hides the complexity of hybrid cloud systems with multiple data sources or 3rd party APIs by decoupling the declaration of an API from its implementation. This powerful concept allows developers to attach so-called resolvers to object-type fields to retrieve data from various sources simultaneously. On top of that, clients can batch queries to retrieve results for multiple object types in a single API request.

A summary of a few critical differences developers should know about can be found in the following table.

Topic	GraphQL	REST
General	Specification and query language	Architectural style
Resource identity	Separated from fetching method	Same as fetching method
Content type(s)	JSON	JSON, XML, HTML, plain text, image
Discoverability	Built-in introspection query	Can be implemented, e.g. with OpenAPI
Endpoints	Single endpoint usually /graphql	Multiple endpoints per resource
HTTP Caching	No	Yes
HTTP methods	POST, GET	POST, GET, PATCH, PUT, DELETE
Response structure	Client defines which fields are returned	Server defines which fields are returned
Typesystem	Strongly typed	Weakly typed
Versioning	Built-in field deprecation	Versioned endpoints

GraphQL vs. REST: Summary

GraphQL has rapidly grown in popularity, and tech companies such as Github, Shopify, Stripe, and Twitter have adopted it in recent years. Gartner® predicted that by 2025, more than 50 percent of enterprises would use GraphQL in production, up from less than 10 percent in 2021.

GraphQL provides a strong type system, only requires integrating a single endpoint, and significantly reduces over- and under-fetching, making it easier for application developers to use. On top of that, it simplifies fetching data from different sources in a single query. With all these advantages, GraphQL is the better alternative to REST APIs.

However, while GraphQL APIs are easier to integrate for application developers, they can be challenging for the teams tasked with creating them. Our mission is to empower teams to build faster with our no-code backend builder that is optimized for developer productivity and instant collaboration. Whether you are a frontend-, backend-, or citizen developer, you can get a fully managed GraphQL server, including a highly scalable database ready in minutes.

Join the GraphQL movement and build powerful apps minus the complexity.

Useful References

• What is GraphQL?
• GraphQL Query
• GraphQL Server
• GraphQL Playground
• GraphQL Tools
• Dissertation about REST by Roy Fielding
• GraphQL specification
• OpenAPI specification
• GraphQL Type Generation