REST or GraphQL?

Few technical choices get as charged as REST versus GraphQL. People talk about them almost like philosophies of life, but for someone building a product, the question is more sober: which way of building the API causes the least hassle for the need you actually have? Here are the differences in practical consequences, without religion – and a clear recommendation to start from.

What the two actually do

An API is the interface where systems fetch and send data. REST and GraphQL are two different ways of shaping that interface.

With REST, the client calls fixed addresses, endpoints, each of which returns a set amount of data. If the app wants a user, it fetches a user endpoint; if it wants the user’s orders, it fetches another. The server decides what each endpoint returns, and the structure is predictable.

With GraphQL, there’s instead a single entry point where the client sends a query for exactly the fields it wants. If the app only needs a user’s name and email, it asks for just that, in a single call, and gets nothing more. Control over what’s fetched shifts from the server to the client.

When GraphQL shines

GraphQL solves a concrete problem: different clients needing different views of the same data. A mobile app wants a small, trimmed-down data set to save on the connection. A website wants more. A partner integration wants something else entirely. With REST, this tends to lead either to many purpose-built endpoints or to everyone fetching too much or too little.

This is GraphQL at its best. Every client asks for exactly what it needs, and new needs can often be met without the server having to build a new endpoint every time. If you have several different consumers of the same data evolving at different paces, that gives a flexibility REST struggles to match.

What GraphQL costs

That flexibility isn’t free. A GraphQL server is more complex to build and operate, and the complexity concentrates in two areas.

The first is performance. When the client can freely query deeply nested data, a single seemingly innocent query can force the server to do heavy work. Protecting against that requires deliberate effort that REST rarely forces on you.

The second is security. With free-form queries, access has to be governed carefully, often field by field, so a client can’t query its way to data it shouldn’t see. The surface to think through gets bigger. On top of that, caching – saving responses to avoid recomputing them – is simple and well-proven in REST via the web’s own infrastructure, but more involved in GraphQL.

The recommendation: REST as the default

Weigh this together and a clear stance emerges: use REST as the default, and reach for GraphQL only once the need is proven. REST is enough for the vast majority of APIs, costs the least in complexity, and rests on a mature toolchain most developers already know. Simple caching and predictable structure are values you shouldn’t give up without reason.

GraphQL becomes the right choice when you can point to the actual problem it solves – several clients with different data views that would otherwise cause hassle. If you can’t, GraphQL adds server and security complexity without paying it back.

Nor does the choice have to apply to the whole system. Many products run REST for most things and add GraphQL exactly where several clients require flexibility. It can be decided per need rather than as a matter of faith.

At Weapp we build both and help you determine which fits your product – without picking a side in advance. Check out our services or get in touch, and we’ll look at your actual needs and land on the right choice.