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Websocket Tutorial Javascript: Javascript Explained

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Websockets are a powerful and secure way to communicate over the Internet. They provide fast, real-time communication for web applications, enabling web developers to create applications with real-time updates without having to reload the page. This has wide applicability, from online poker games, to collaborative editing tools, or even using a website as a remote control for an Internet of Things device. In this tutorial, we will be explaining the basics of Websockets, setting up and connecting to a Websocket server, understanding the basics of JavaScript, utilizing Websockets for real-time communication, using examples to illustrate Websockets in action, security considerations, as well as alternatives to Websockets in JavaScript.

What is Websocket and How Does it Work?

Websocket is an advanced technology that enables a persistent, bidirectional communication between a client and a web server over a single TCP connection. This allows for an ongoing exchange of data in real-time, without having to send multiple requests and responses back-and-forth. This is especially valuable when creating highly interactive web applications, as it provides an efficient and effective means of obtaining structured data updates quickly and easily.

To initiate a Websocket connection, the client must send an opening handshake to the server on startup. The handshake is sent using the Hypertext Transfer Protocol (HTTP) and is formatted like any standard HTTP request. After the handshake has been validated by the web server, the connection is then established, and the client and the server can exchange data without the need for further handshakes.

Once the Websocket connection is established, the client and server can send messages back and forth in real-time. The messages are sent in a binary format, which is more efficient than the text-based format used in traditional HTTP requests. This allows for faster data transfer and more efficient communication between the client and server. Additionally, Websocket connections are persistent, meaning that the connection remains open until it is closed by either the client or the server.

Setting Up and Connecting to a Websocket Server

Creating a Websocket connection begins with initializing your server. Typically, this consists of having to install a Websockets library or package such as ws for Node.js applications. After installation, you will then need to set up your server code. Depending on your framework and the library chosen, this will vary. However, a basic example looks something like this:

const WebSocket = require('ws'); const wss = new WebSocket.Server({port: 8080});

Once set up, you can open a new connection by simply sending an HTTP request with JavaScript code to the server. Use the following code to do this:

var ws = new WebSocket('ws://localhost:8080');

Replacing the hostname and port in ws://localhost:8080 with your server address or IP address will be necessary if you are using an external or hosted server.

Once the connection is established, you can start sending and receiving data. To send data, use the send() method, which takes a string as an argument. To receive data, use the onmessage event handler, which will be triggered when data is received from the server.

Understanding the Basics of Javascript

It’s important to understand some of the basic concepts of JavaScript if you want to effectively use Websockets together. JavaScript is an object-oriented programming language that is used mainly to create interactive web pages. It is a loosely-typed language that has its own built-in libraries and functions for writing efficient code.

To use Websockets with JavaScript, you must create an instance of a WebSocket object by calling the WebSocket constructor with a valid URL parameter. Once the instance is created, you must open the connection by calling the open() method on the instance. After the connection is open, you’ll be able to issue messages from either side.

In addition to the open() method, there are several other methods available for working with Websockets. These include the send() method, which is used to send data to the server, and the close() method, which is used to close the connection. You can also use the onmessage() method to listen for incoming messages from the server.

Utilizing Websocket for Real-Time Communication

Websockets provide for fast and reliable real-time communication between two points on the internet. This means that any application that requires a constant stream of data can benefit from implementing Websockets into their workflow. By utilizing them, developers can make sure they are receiving constant updates from the server-side applications and respond to events quickly and accurately.

One example of this type of application is a chat system where messages are sent between two users in real-time. The user sends their message to the server via a Websocket connection, then the message is broadcast back to all connected users on the same Websocket channel. This allows users to communicate with one another in real-time without having to wait for data from the server.

Websockets also provide a secure connection between the two points, as all data is encrypted before being sent. This ensures that any sensitive information is kept safe and secure, and that the data is not tampered with in transit. Additionally, Websockets are able to handle large amounts of data, making them ideal for applications that require a lot of data to be transferred quickly and reliably.

Examples of Websockets in Action

Websockets can be used for many different types of web applications and services. Some examples include collaborative editing tools, multiplayer online games, real-time monitoring applications, and even peer-to-peer communication structures. With Websockets, developers can create custom solutions for specific needs without needing to reinvent the wheel with every project.

For example, if you wanted to create an online game that allowed users to play against each other in real-time, you could use Websockets to send updates between the two players over the internet. This would allow both players to stay up-to-date on each other’s movements in the game and respond accordingly.

Websockets can also be used to create real-time chat applications, allowing users to communicate with each other in real-time. This can be used for customer service applications, online gaming, or even just for fun. Websockets can also be used to create real-time data visualizations, allowing users to view data in real-time and make decisions based on the data they are seeing.

Client-Side Libraries for Websockets in Javascript

Websockets can also be used with JavaScript libraries such as, Primus, and Faye that help simplify the process of setting up and managing websocket connections in a browser environment. These libraries can help developers quickly set up their websocket connections and provide useful features like fallback support or message broadcasting.

Security Considerations with Websockets

As with any type of communication over an open network, it is important to keep security in mind when implementing websockets for any application. Setup should start with TLS (Transport Layer Security) encryption for increased security. Additional steps might include additional authentication measures such as OAuth for additional layers of security.

Alternatives to Websockets in JavaScript

Websockets are not the only way to create real-time applications and services in JavaScript. Other alternatives such as AJAX requests, Server Sent Events (SSE), and Long Polling can provide similar results in certain scenarios. However, these technologies cannot provide fast data transfers in comparison to websockets.


Websockets make it possible to create powerful applications with real-time data streams and rapid updates. By understanding the basics of JavaScript in combination with how websockets work, developers can quickly create applications with seamless communication between clients and servers.

Nisha Kumari

Nisha Kumari

Nisha Kumari, a Founding Engineer at Bito, brings a comprehensive background in software engineering, specializing in Java/J2EE, PHP, HTML, CSS, JavaScript, and web development. Her career highlights include significant roles at Accenture, where she led end-to-end project deliveries and application maintenance, and at PubMatic, where she honed her skills in online advertising and optimization. Nisha's expertise spans across SAP HANA development, project management, and technical specification, making her a versatile and skilled contributor to the tech industry.

Written by developers for developers

This article was handcrafted with by the Bito team.

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