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SocketIO Vs. WebSocket

10 March 2021

User expectations have changed a lot over the last couple of years, we now live in an age where it is expected that content is instant and data is real-time. Web technology has improved and using WebSockets or SocketIO can now offer two-way (or full-duplex) data transfer between client and server.

What is a WebSocket:

WebSocket is a pre-defined Protocol that provides (TCP) bi-directional communication between a server and a client, in the case of real-time data solutions we provide a market data server to which a client connects to.

What is SocketIO:

SocketIO is a JavaScript implementation of the WebSocket protocol, the library originally written by Guillermo Rauch and released under the MIT License. Again this is a bi-directional communication system that facilitates communication between a client and server.

What do we mean by Client Side and Server Side:

Client-Side :

A client-side could be browser-based or an application running on a consumer machine. In the context of real-time data streaming, this is the consumer of the data, a program on a client machine or a browser.


Server Side accepts connections from the client and then streams data while the connection is still alive. In the context of TraderMade, this is forex data, the client connects to the server and sends login details and symbol requests. The server processes this information and adds the client to the pool of clients listening for that data, when new data even is received it is broadcasted to the connected clients.

Let's talk about technologies:


What are the key features of WebSocket?

  • Simplifies Client-Server Communication: The WebSocket protocol simplifies the communication between the client and the web server and adheres to a pre-defined standard that any developer can write to.
  • Full-Duplex Communication: This means that the client and server can send data at the same time. As appose to Half-Duplex systems that work on a send and receive basis where data can only travel in one direction at a time.
  • Platform and Language Independence: The protocol is language independent. So, it's possible to send data from a Java client on a Linux server to a Python client on a Windows machine.

WebSocket URL structure

The WebSocket URL structure adheres to the same principle as a standard website URL structure that you are probably familiar with but has a few subtle changes.



or SSL


So what is the purpose of the WebSocket and how can it be useful?

  • Persistent Communication: The connection between client and server is simple, robust, and persistent. In the context of our API, it means we can have clients establish a connection to our data server and we can stream them fast a reliable Forex, Metals, and CFD rates in real-time.
  • Reliable Standard: The protocol is established and defined and many reliable libraries are available in multiple programming languages, such as Java, C#, Golang, and Python to name a few.
  • Fast and Easy Integration: WebSockets are simple and fast and help reduce development time.

For the implementation of the WebSocket please refer to our tutorials page.

But before you rush off a start build there is another option!!


SocketIO is an implementation of the WebSocket protocol so all the things that are great about WebSocket are also great about SocketIO, but it has some advantages and some disadvantages.

What are the key advantages of SocketIO?

  • Event-based WebSocket wrapper between client and server.
  • Handles Proxy and Load Balancers: SocketIO has the ability to handle connections routed via proxy servers and load balancers.
  • Client and Server: Both client and Server need to have implemented SocketIO libraries for it to work.
  • Fallback Options

What are the key disadvantages of SocketIO?

  • It's a library: Where WebSocket is a protocol, SocketIO is a library, and so have a dependency on those libraries doing what you need and working as expected.
  • Client and Server: Both client and Server need to have implemented SocketIO libraries for it to work.
  • Fewer Implementations: Platform and language coverage is much greater for WebSockets.

WebSocket vs SocketIO Comparison


WebSocket is a protocol while SocketIO is a library that mimics a WebSocket connection. SocketIO is feature rich and versatile but is limited by language coverage.

Before we roll our sleeves up and get coding - Conclusion

WebSocket vs Socket.IO, not really much to say WebSockets are the protocol and SocketIO is a decent attempt at improving the standard. For the majority of projects, standard WebSocket will fill all requirements.