Which API Should You Use? A Simple Guide to REST, GraphQL, WebSocket, gRPC & SOAP

Hey!

So, you’re building something cool, maybe a website, a mobile app, or a backend service, and you keep hearing about all these different types of APIs. REST, GraphQL, WebSockets, gRPC, SOAP… it can feel like alphabet soup, right?

Don't worry, you're not alone. In this post, I'm going to walk you through the 5 main types of APIs in plain English. I’ll explain what they are, when to use them, and what makes each one special. Let’s jump in!

1. REST API (Representational State Transfer)

REST is the most popular type of API out there. You’ve probably already used it, even if you didn’t realize it. It works over HTTP, which means it uses the same basic system your browser uses to visit websites.

In REST, everything is treated like a "resource". For example, users, posts, or products, each one has its own URL. You use standard HTTP methods to talk to these resources:

• GET to read data
• POST to add new data
• PUT or PATCH to update
• DELETE to remove

Why people love REST:

It’s easy to understand, works with pretty much any language, and plays nicely with tools like Postman or fetch in JavaScript.

Example:

If you want a list of users, you just call: GET https://api.example.com/users

And it returns something like:

[
  { "id": 1, "name": "Alice" },
  { "id": 2, "name": "Bob" }
]

But here’s the catch:

Sometimes you end up getting too much data or not enough. Maybe you only want names, but the API gives you the whole user profile. That’s where GraphQL can help.

2. GraphQL (Graph Query Language)

GraphQL is like REST’s smarter cousin. It was made by Facebook, and it gives you more control over the data you get.

Instead of hitting different endpoints for different things, GraphQL uses just one. You send a query and say exactly what you want. The server replies with only that.

Why GraphQL is cool:

• You don’t get extra data you don’t need
• You can fetch related data in a single request
• It’s great for frontend apps like React or Vue

Example:

Let’s say you want a user’s name and their post titles. You’d write:

{
  user(id: 1) {
    name
    posts {
      title
    }
  }
}

That’s all you get back, just the name and titles.

Downsides?

It can be a bit harder to set up and cache. Also, if your team is used to REST, switching to GraphQL might take some time to learn.

3. WebSocket API

Now let’s talk about something totally different: real-time communication.

REST and GraphQL both work by asking the server for stuff. But what if you want the server to push updates to you automatically, like in a chat app or a live stock ticker?

That’s where WebSockets come in.

A WebSocket API lets you open a connection that stays open. Both sides, client and server, can send messages to each other any time.

Perfect for things like:

• Chat apps
• Multiplayer games
• Live dashboards
• Notifications

How it works:

Once the connection is open, the server can send data whenever something changes. No need to keep asking "is there anything new?"

The tricky parts:

WebSockets are harder to scale, and you’ll need to handle stuff like reconnecting if the connection drops. But if you need real-time updates, they’re worth it.

4. gRPC (gRPC Remote Procedure Call)

gRPC is a modern API framework developed by Google. It's designed for high-performance communication between services, especially in microservice systems.

It doesn’t use JSON like REST. Instead, it uses a compact and fast format called Protocol Buffers (protobuf), which saves both time and bandwidth.

With gRPC, you define your API in a .proto file, and the system generates code for your programming language. No need to manually write HTTP logic.

Why use gRPC:

• It’s much faster than REST
• Great for microservices talking to each other
• Supports real-time streaming

Use cases:

If you’re building a system where different backend services need to talk quickly, like an e-commerce platform with separate services for users, orders, and payments - gRPC is a great fit.

Not ideal for:

Web browsers or public APIs. It’s mostly used behind the scenes.

5. SOAP (Simple Object Access Protocol)

SOAP is one of the oldest API styles still in use today. It stands for Simple Object Access Protocol, and it's known for being very strict and structured.

It uses XML to send and receive data and often includes built-in security and error handling features. While it feels a bit heavy compared to REST or GraphQL, SOAP is still widely used in industries like banking, insurance, and healthcare.

Why SOAP is still around:

• It has strong built-in security
• It’s good for complex transactions
• It follows strict standards, which some companies require

Example:

A SOAP request might look like this:

<soap:Envelope>
  <soap:Body>
    <GetUser>
      <UserId>123</UserId>
    </GetUser>
  </soap:Body>
</soap:Envelope>

Downsides:

It’s harder to read, very verbose, and slower to work with. But if your job involves big enterprise systems, you’ll probably see it around.

Quick Comparison

Here’s a simple chart to help you remember the differences:

Final Thoughts

So, which API should you choose? It depends on what you're building.

• Just want something simple? Go with REST.
• Need more control in the frontend? Try GraphQL.
• Building real-time features? WebSockets are your friend.
• Need performance and speed for backend systems? gRPC is perfect.
• Working with banks or government systems? You might need to deal with SOAP.

Hope this helped make things clearer! APIs don’t have to be scary, once you know what each one does, choosing the right one becomes a lot easier.

Let me know if you’ve used any of these before, or if you have questions. I’d be happy to chat more!