Introduction

Over the years, web communication protocols have evolved significantly. There was a time when SOAP dominated, then REST emerged — and it came to stay. Later, GraphQL and gRPC appeared and quickly gained adoption.

Today, REST, GraphQL, and gRPC share the spotlight.

So the question is: when should you use each one?

REST

REST is still the standard choice today. If you're unsure which approach to take, start with REST.

It works best when your API:

• will be public
• is a simple CRUD
• needs to be easy to implement
• needs to be widely compatible

This is an example of a typical REST request:

POST /api/customers

Content-Type: application/json

{"email":"john@domain.com","name":"John Doe"}

gRPC

gRPC is a high-performance communication protocol that sends data in a compact binary format instead of JSON.

You should consider gRPC when:

• communication happens between microservices
• low latency is critical
• you need strict contracts (strong typing)
• performance is a top priority

Instead of using URLs and HTTP verbs like REST, gRPC uses typed methods:

Service: CustomerService
Method: CreateCustomer

GraphQL

GraphQL is the most flexible option. It allows clients to request exactly the data they need.

Use GraphQL when:

• your data has many relationships
• you want to avoid multiple requests
• the frontend needs to choose exactly what data it gets
• you want to avoid fetching too much or too little data

Here is an example of a GraphQL query:

query{product{nameprice}}

Conclusion

It's great to have multiple protocols to choose from, each one solving problems that the others don’t.

I hope this post helps you decide which protocol to use the next time you're designing a system.