WebTransportDatagramDuplexStream: outgoingHighWaterMark property

Limited availability

This feature is not Baseline because it does not work in some of the most widely-used browsers.

Secure context: This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.

The outgoingHighWaterMark property of the WebTransportDatagramDuplexStream interface gets or sets the high water mark for outgoing chunks of data — this is the maximum size, in chunks, that the outgoing WritableStream's internal queue can reach before it is considered full. See Internal queues and queuing strategies for more information.

Note: This feature is available in Web Workers


A number.


const url = "https://example.com:4999/wt";

async function initTransport(url) {
  // Initialize transport connection
  const transport = new WebTransport(url);

  // The connection can be used once ready fulfills
  await transport.ready;

  const datagrams = transport.datagrams;

  // set outgoingHighWaterMark
  datagrams.outgoingHighWaterMark = 20000;

  // get outgoingHighWaterMark


# dom-webtransportdatagramduplexstream-outgoinghighwatermark

Browser compatibility

BCD tables only load in the browser

See also