The Ultimate Guide to Safari Websocket

Websockets have revolutionized the way we interact with websites and web applications. They enable real-time, bi-directional communication between clients and servers, allowing for a more seamless and dynamic user experience. While websockets are supported by most modern browsers, Safari has some unique features and considerations to keep in mind when using websockets. In this guide, we’ll explore everything you need to know about Safari websockets, from the basics to advanced usage and troubleshooting.

What are Websockets?

Websockets are a protocol that allows for real-time, bidirectional communication between web clients and servers. Unlike traditional HTTP requests, which are unidirectional and require a new connection to be established for each request, websockets use a single, persistent connection that remains open as long as necessary. This enables a more seamless and efficient exchange of data between the client and server, making it possible to create dynamic, real-time applications such as chat rooms, online gaming, and collaborative editing tools.

How do Websockets Work in Safari?

Safari, like most modern browsers, supports websockets through a JavaScript API called WebSocket. This API provides a simple interface for creating and managing websocket connections, including methods for opening and closing connections, sending and receiving data, and handling errors and events. Safari also supports the WebSocket object in Web Workers, which allows for concurrent connections and offloading of processing tasks to background threads.

How to Use Safari Websockets

Creating a Connection

To create a websocket connection in Safari, you first need to instantiate a WebSocket object and pass in the URL of the server to connect to. For example:

var socket = new WebSocket("ws://");

This will create a new websocket connection to the server at “ws://”. Note that the URL must use the “ws://” or “wss://” scheme to indicate a websocket connection, rather than the traditional “http://” or “https://” scheme used for HTTP requests.

Sending and Receiving Data

Once the connection is established, you can send data to the server using the send() method of the WebSocket object. For example:

socket.send("Hello, server!");

The server can then respond with its own data, which can be received by adding an event listener for the “message” event:

socket.addEventListener("message", function(event) {
   console.log("Received data from server: " +;

This will print any data received from the server to the console.

Closing a Connection

To close a websocket connection in Safari, you can call the close() method of the WebSocket object:


This will cleanly terminate the connection with the server. You can also pass in a status code and reason phrase to indicate the reason for closing the connection:

socket.close(1000, "Goodbye!");

Advanced Usage

Binary Data

Websockets in Safari support both text and binary data. To send binary data, you can pass in an ArrayBuffer, Blob, or TypedArray object to the send() method:

var buffer = new ArrayBuffer(4);
var view = new Int32Array(buffer);
view[0] = 12345;

The server can then decode the binary data as needed, using techniques such as ArrayBufferView, Blob, or FileReader.

Extensions and Protocols

Websockets in Safari support several extensions and protocols that can be negotiated during the initial handshake. Extensions provide additional features such as compression, while protocols define a specific format for the data exchanged between the client and server. To specify an extension or protocol, you can include it as a parameter in the WebSocket constructor:

var socket = new WebSocket("ws://", "my-protocol");

The server can then respond with its own list of supported extensions and protocols, and negotiate the best match with the client.

Error Handling

Websockets in Safari can encounter errors due to various reasons such as network connectivity, server unavailability, or invalid data. To handle errors, you can add event listeners for the “error” and “close” events:

socket.addEventListener("error", function(event) {
   console.log("Error: " + event.message);
socket.addEventListener("close", function(event) {
   console.log("Closed with status " + event.code + " and reason " + event.reason);

This will print any error messages or close events to the console.


Compatibility Issues

While websockets are widely supported across modern browsers, there may be some compatibility issues to keep in mind when using Safari websockets. For example, Safari has a lower maximum message size than some other browsers, which may cause issues with larger data transfers. Additionally, Safari may have stricter security policies that require additional configuration on the server side.

Firewall and Proxy Issues

Websockets in Safari may also encounter issues with firewalls and proxies that block or restrict websocket traffic. To mitigate these issues, you can use techniques such as reverse proxies, load balancing, or tunneling through other protocols such as HTTP.

Debugging Techniques

If you encounter issues with Safari websockets, there are several debugging techniques you can use to diagnose and resolve the issue. These may include using browser developer tools to inspect network traffic, logging server-side errors and events, or using third-party tools such as Wireshark or Fiddler to capture and analyze websocket traffic.


  1. What is the difference between websockets and AJAX?
  2. Websockets and AJAX are both techniques for communicating between web clients and servers, but they have some key differences. AJAX uses traditional HTTP requests and responses, which are unidirectional and require a new connection for each request. Websockets, on the other hand, use a persistent, bidirectional connection that allows for real-time, event-driven communication. This makes websockets more suitable for applications that require frequent updates or real-time interaction, such as chat rooms or collaborative editing tools.

  3. What are some popular applications of websockets?
  4. Websockets are used in a wide range of applications, including chat rooms, online gaming, real-time data visualization, and collaborative editing tools. They are also used in enterprise applications such as financial trading platforms, supply chain management systems, and customer service portals.

  5. Do all browsers support websockets?
  6. Most modern browsers support websockets, including Safari, Chrome, Firefox, and Edge. However, older browsers or devices may not support websockets, or may require additional configuration or polyfills.

  7. Are websockets secure?
  8. Websockets can be secured using TLS encryption, which provides a secure channel for transmitting data between the client and server. However, like any network protocol, websockets can be vulnerable to security issues such as cross-site scripting (XSS), cross-site request forgery (CSRF), and denial-of-service (DoS) attacks.