BackWebsockets vs REST

WebSocket Vs. REST

23 June 2021

We get asked daily, “what is the difference between WebSockets and the REST API?", with this article, we attempt to declutter the jargon surrounding these technologies and provide a simple explanation for their use. The article is mainly to make the reader understand whether WebSockets or REST is more appropriate for their data needs. Before we get into WebSocket and REST API uses, let's understand what they are.

What is a WebSocket?

Websocket is a computer communication protocol, or in simple terms "a set of rules" for two computer machines to communicate with each other. It establishes bidirectional communication between two computers over a TCP Socket. Let's understand how the WebSocket helps in providing data seamlessly. A WebSocket in essence establishes a two-way connection between the client (requesting data) and the server (sending data), which is continuous. One example is a phone call where once you connect a call, it enables two-way communication seamlessly. You can read a more detailed explanation of the Websockets here.

What is a REST API?

REST is a set of constraint or design principles to create web services that use the HTTP protocol to communicate between the client and the server, however, the communication is unidirectional at any given time. hence the REST API only provides data on request. It is akin to a vending machine: you will need to ask for the right resource to get one.

What purposes is Websocket used for?

Websocket is used largely where data delivery is continuous and duplex, for example, for low latency and high-frequency forex data feed. It will be resource-heavy for the client to request 100s of rates every second using REST, whereas the Websocket client can receive 100s of rates a second without being too resource-intensive.

What purposes is REST API used for?

REST API is used where data demands are not continuous and stateless. For example, requesting live data when your application needs it or requesting historical timeseries data to display a chart. REST is a resource-based concept akin to our example of the vending machine, however, is a more apt extension of that analogy where you can online request your resource and have it delivered anywhere.

When to use Websocket and when to use REST?

Websockets vs REST is not really a "what is the best?" question but rather a "what is more appropriate?" question. REST is more versatile and can deliver almost all the available resources provided by us. It works great when data needs are ad-hoc, however, it is not useful when data delivery needs to be super fast (like more than 10 requests a second) and continuous where every tick rate matter. WebSocket is ideal when no rates need to be missed in delivery (like when tick data analysis is required) and speed is of the essence. Websockets are ideal in scenarios with higher loads.


WebSockets and REST are both technically brilliant in their own right, hence their recent popularity. The appropriate choice is dependent on user data needs. We hope this has helped improve your understanding of both delivery methods, however, if you would still like to know more please chat with one of our experts now.