REST API vs GraphQL: A performance comparison

Whichever application you use, APIs (application programming interfaces) are responsible for everything to interact between components. APIs specify how software components should interact and link together with a defined set of routines, communication protocols, and tools.

Basically, APIs act as a bridge between server and client. On one end the server that serves the API, and on the other end the client that consumes the API. Thus, APIs integrate different systems together by allowing the backends of various apps to communicate with one another.

For example, when you upload your travel photos to Instagram, APIs come into effect in two major contexts: while transferring the photo from your phone to the server and then while making it viewable across your network feeds. This advanced integration that is powered by API provides all the building blocks for communication adhering to specific standards and specifications.

REST vs GraphQL: API Design Patterns

In general, there are two API standards now followed by developers for designing a web API – REST and GraphQL. Introduced in 2000, REST is still considered to be a de facto way for building APIs. However, after GraphQL was open-sourced by Facebook in 2015, it now seems like an alternative to REST since it fixes many problems that developers found with RESTful architecture.

Is the new API standard, GraphQL really better? Or should you stick to good old-fashioned REST? Let’s take a deep dive into the pros and cons of each, similarities and differences between them and figure out which one makes sense for your next application development.

What is REST API?

REST is a design pattern for building distributed systems based on hypermedia. It is independent of any underlying protocol and is not necessarily tied to HTTP. However, most standard REST implementations use HTTP as the application protocol.  

Pros and cons of REST API

REST offers great concepts such as stateless servers and structured access to resources. It provides a great deal of flexibility. Data is not tied to resources or methods, so REST can handle multiple types of calls, return different data formats and even change structurally with the correct implementation of hypermedia. This flexibility allows developers to build an API that meets your application needs while also meeting the diverse clients’ requirements.

Nevertheless, REST APIs have shown to be too inflexible to keep up with the rapidly changing requirements of the clients that access them. With REST, you have to make multiple requests to different endpoints to fetch the required data. You are also over-fetching since the endpoints return additional information that’s not needed.

What is GraphQL?

GraphQL is an open-source data query language for APIs. It was developed to cope with the need for more flexibility and efficiency. Especially, it is designed to build client applications by providing an intuitive and flexible syntax for describing their data requirements and interactions precisely.

Pros and cons of GraphQL

GraphQL also offers some interesting concepts – specifically fragments: On the client-side, you can use GraphQL fragments to split a large query into smaller parts. The smaller parts can be used to define the query of the respective use case such as data requirements per UI component. Finally, a (large) query can then be assembled from the fragments, which contains all data requirements of all components and the required data can then be loaded from the server using a single request. Thus, GraphQL merges all the RESTful endpoints into one and uses less network traffic.

Having said that, the downside of GraphQL is that special attention must be given to performance on the server-side. Since more freedom is gained at the client-side with flexible data requirements, you have to invest more thought in avoid running into server performance issues.  

How REST performance is different from GraphQL?

A major difference between the two standards is who defines the response – whether the client or server. In REST, the server defines the state of the response and in GraphQL, the client defines the shape of the response. Apart from this factor, there are many other notable differences that are summarized below:   

1. REST uses mostly HTTP protocol for data transfer. In GraphQL, it’s up to you as an implementer to decide the protocol for transmitter. Therefore, you can have HTTP, web sockets, MQTT, etc.
2. REST needs one endpoint URL per resource, whereas GrahpQL usually requires only one endpoint per application.
3. REST uses HTTP verb (GET, POST, DELETE, etc) for semantics and GraphQL uses queries and mutations for semantics
4. REST maintains separate documentation for your endpoints and GraphQL is self-documented via schema introspection

Which one is right for your project?

REST and GraphQL can complement each other well, and they are used for specific purposes. There will be some cases that might be an overkill for GraphQL but are perfect for REST services and vice versa. For instance, if there is only going to be one application on a single platform, then REST is preferred, given that developers are already experienced in REST and they don’t need to learn an additional technology.  

When building REST-based applications, you have to work backward keeping in mind the customer experience. But in the case of GraphQL, the client and the server can be worked upon independently. As such, choosing the right API standard depends on your project requirements. If you are beginning a new project, you can consider working solely with GraphQL, but it’s not the right approach to blindly trust GraphQL that will solve every problem.  

Designing a great API spec will save you time and money in the long run. At Infinijith Technologies, we follow several conventions for designing a web API. So, to discover whether REST or GraphQL is the right one for your project, you can connect with our experts for a free consultation.