WebSocket API and protocol explained: How they work, are used and more

Should be used when closing the connection and there is no expectation that a follow-up connection will be attempted (e.g., server shutting down, or browser navigating away from the page). Optional header field, initially sent from the client to the server, and then subsequently sent from the server to the client. The server needs to include this field together with one of the selected subprotocol values (the first one it supports from the list) in the response. For example, WhatsApp uses WebSocket with the Extensible Messaging and Presence Protocol (XMPP) for user communication. Let’s explore some use cases for which WebSocket is particularly suitable.

what is websocket used for

In the case of transparent proxy servers, the browser is unaware of the proxy server, so no HTTP CONNECT is sent. Using encryption is not free of resource cost, but often provides the highest success rate, since it would be travelling through a secure tunnel. Whenever the client makes a new HTTP server request, the default behavior is to open a new HTTP connection. This is inefficient because it uses bandwidth on recurring non-payload data and increases latency between the data transfers. Basic HTTP requests work well for many use cases, such as when someone needs to search on a web page and receive relevant, non-time-sensitive information.

How do WebSockets work (and their connections)

WebSockets have gained popularity in recent years due to their ability to provide low-latency, real-time communication in web applications. In this article, we’ll explore what WebSockets are, how they work, and some common use cases. The first realtime web apps started to appear in the 2000s, attempting to deliver responsive, dynamic, and interactive end-user experiences. Similarly, a Zoom user sends a server request by clicking on a Zoom link, requesting to join a meeting.

  • Organizations in the transport and delivery industries, such as Uber and Lift, leverage WebSocket to      build their ordering and dispatch apps.
  • Low latency means that there is very little delay between the time you request something and the time you get a response.
  • The protocol is designed to allow clients and servers to communicate in realtime, allowing for efficient and responsive data transfer in web applications.
  • When using HTTP, clients—such as web browsers—send requests to servers, and then the servers send messages back, known as responses.
  • This means that both parties can send data to each other simultaneously, rather than sending data one way at a time using HTTP protocols, as has been done before.

To understand more, we have to look at the parties involved in web communication and contrast how WebSockets work compared to HTTP. Discover the most common WebSocket security vulnerabilities and how to prevent them through a combination of modern security approaches and testing tools. Note that older versions of these browsers either don’t support WebSockets, or have limited support.

Establishing WebSocket Connections

In particular, it’s essential to ensure that the WebSocket connection is authenticated correctly and that all data sent over the connection is encrypted to prevent eavesdropping or tampering. WebSocket is a communication protocol that enables real-time data exchange between a web server and a client, such as a web browser. Unlike the traditional HTTP method of loading web pages, where each piece of data requires a separate request and response, WebSocket keeps a single connection open for as long as the application is running. Now that you have an idea about what WebSockets are, you must be wondering how it’s different from HTTP (a request-response protocol) and what protocol WebSocket is used for. A WebSocket differs from HTTP as its connection is kept open, and data is transferable between the client and server at any time. This makes it well-suited for real-time web applications like online gaming, chat applications, and stock tickers.

what is websocket used for

The process of closing a WebSocket connection is known as the closing handshake. In addition to the opcode, the close frame may contain a body that indicates the reason for closing. This body consists of a status code (integer) and a UTF-8 encoded string (the reason). Each WebSocket frame sent by the client to the server needs to be masked with the help of a random masking-key (32-bit value). This key is contained within the frame, and it’s used to obfuscate the payload data.

Live chat and instant messaging

WebSockets initiate continuous, full-duplex communication between a client and WebSocket server. This reduces unnecessary network traffic, as data can immediately travel both ways through a single open connection. Websockets also enable servers to keep track of clients and “push” data to them as needed, what is websocket which was not possible using only HTTP. When long polling, the client polls the server, and that connection remains open until the server has new data. The server sends the response with the relevant information, and then the client immediately opens another request, holding again until the next update.

what is websocket used for

In this article, we have explored what a WebSocket connection is and what is a WebSocket protocol. WebSockets are an essential technology that enables two-way communication between a client and a server over a single, long-lived connection. They are designed to provide real-time, low-latency communication between a web application and a server, allowing for a more interactive and dynamic user experience.

Long polling vs. Web Sockets

Each time a request is sent from the client and the response is sent from the server, a new connection is made between the two. The handshake involves sending an HTTP upgrade request header from the client to the server, requesting a protocol switch from HTTP to WebSocket. The server then responds with an upgrade response, acknowledging the switch.

what is websocket used for

To learn more about the distinction between websockets and HTTP, you can check out some of the best Software Development courses online. On the other hand, WebSockets establish a persistent connection between the client and the server. This means that once the connection is established, the client and the server can send data to each other at any time without continuous polling requests. This allows realtime communication, where updates can be sent and received instantly. WebSockets allow two-way communication between client and server, meaning that both sides can send messages back and forth at any time. This allows applications to have real-time features such as chat rooms, multiplayer games, live weather reports, and stock quotes without constantly polling for server updates (which would be very inefficient).

WebSocket are an essential client-server communication tool and one needs to be fully aware of its utility and avoid scenarios to benefit from its utmost potential. Web application and API protection (WAAP) in any customer environment — all via one integrated platform. Full duplex means that data can be sent either way on the connection at any time. A web application (e.g. web browser) may use the WebSocket interface to connect to a WebSocket server. After the protocol was shipped and enabled by default in multiple browsers, the RFC 6455 was finalized under Ian Fette in December 2011. Google Chrome was the first browser to include standard support for WebSockets in 2009.

It allows you to build realtime web applications by providing a simple API for creating WebSockets connections. SignalR supports server-side and client-side implementations and can be used with .NET, JavaScript, and other languages. It also offers automatic connection management, broadcasting messages, and scaling across multiple servers. WebSockets also allow for bidirectional communication, which means that chat servers can push new messages to clients in real-time rather than waiting for the client to request updates.

The client is terminating the connection because the server failed to negotiate an extension during the opening handshake. The endpoint is terminating the connection due to receiving a data frame that is too large to process. The connection is being terminated because the endpoint received data of a type it cannot handle (e.g., a text-only endpoint receiving binary data). In direct relation to Sec-WebSocket-Key, the server response includes a Sec-WebSocket-Accept header.