Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

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

The incomingHighWaterMark property of the WebTransportDatagramDuplexStream interface gets or sets the high water mark for incoming chunks of data — this is the maximum size, in chunks, that the incoming ReadableStream'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 incomingHighWaterMark
  datagrams.incomingHighWaterMark = 20000;

  // get incomingHighWaterMark


# dom-webtransportdatagramduplexstream-incominghighwatermark

Browser compatibility

BCD tables only load in the browser

See also