REST vs SOAP: Two Ways APIs Talk, but Not the Same Way

When building an API, you've probably heard of REST and SOAP.

Both allow applications to communicate with each other, but they take very different approaches.

The simplest way to think about it is this:

REST is flexible and lightweight. SOAP is strict and structured.

What is REST?

REST is an architectural style commonly used for web APIs.

It usually works with standard HTTP methods:

• GET — retrieve data
• POST — create data
• PUT — update data
• DELETE — remove data

For example:

GET /api/users/47

A typical response might look like:

{
  "id": 47,
  "name": "John",
  "email": "[e-mail]"
}

REST commonly uses JSON because it is lightweight and easy for both humans and applications to work with.

What is SOAP?

SOAP is a protocol with strict rules for how messages are structured and exchanged.

SOAP messages are typically written in XML.

A request might look more like this:

<soap:Envelope>
  <soap:Body>
    <GetUser>
      <UserId>47</UserId>
    </GetUser>
  </soap:Body>
</soap:Envelope>

Compared to REST, SOAP can feel more verbose.

But that strict structure is intentional.

SOAP supports standardized features around security, reliability, and transactions, which is one reason it is still used in some enterprise and financial systems.

REST vs SOAP at a Glance

REST	SOAP
Architectural style	Protocol
Commonly uses JSON	Uses XML
Lightweight	More structured and verbose
Flexible	Strict standards
Usually uses HTTP	Can work with different transport protocols
Popular for modern web APIs	Common in enterprise and legacy integrations

So, Which One Should You Use?

For most modern web applications, REST is usually the simpler choice.

Building a frontend with React that communicates with a .NET API?

REST will likely feel natural:

GET /api/products
POST /api/products
DELETE /api/products/10

But if you're integrating with an enterprise system that requires strict contracts, advanced messaging standards, or SOAP-based security, then SOAP may be the requirement.

The important thing is that this is not really about choosing the “new” technology over the “old” one.

It's about choosing the communication style that fits the system.

Key Takeaway

REST focuses on simplicity, flexibility, and resource-based APIs.

SOAP focuses on strict contracts and standardized messaging.

Use REST when you want a lightweight and flexible API. Use SOAP when your system requires the strict standards and enterprise-level features SOAP is designed for.