WebSocket: send() method

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.

The WebSocket.send() method enqueues the specified data to be transmitted to the server over the WebSocket connection, increasing the value of bufferedAmount by the number of bytes needed to contain the data. If the data can't be sent (for example, because it needs to be buffered but the buffer is full), the socket is closed automatically. The browser will throw an exception if you call send() when the connection is in the CONNECTING state. If you call send() when the connection is in the CLOSING or CLOSED states, the browser will silently discard the data.

Syntax

js
send(data)

Parameters

data

The data to send to the server. It may be one of the following types:

string

A text string. The string is added to the buffer in UTF-8 format, and the value of bufferedAmount is increased by the number of bytes required to represent the UTF-8 string.

ArrayBuffer

You can send the underlying binary data used by a typed array object; its binary data contents are queued in the buffer, increasing the value of bufferedAmount by the requisite number of bytes.

Blob

Specifying a Blob enqueues the blob's raw data to be transmitted in a binary frame (the Blob.type is ignored). The value of bufferedAmount is increased by the byte size of that raw data.

TypedArray or a DataView

You can send any JavaScript typed array object as a binary frame; its binary data contents are queued in the buffer, increasing the value of bufferedAmount by the requisite number of bytes.

Return value

None (undefined).

Exceptions

Specifications

Specification
WebSockets Standard
# ref-for-dom-websocket-send①

Browser compatibility

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