WebTransport: reliability property

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

The reliability read-only property of the WebTransport interface indicates whether the connection supports reliable transports only, or whether it also supports unreliable transports (such as UDP).

Note: This feature is available in Web Workers

Value

A string with one of the following values:

pending

The connection has not yet been established. The reliability is not yet known.

reliable-only

The connection only supports reliable transports.

supports-unreliable

The connection supports both unreliable and reliable transports.

Examples

js

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

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

  // Once ready fulfils the connection can be used
  // Prior to this the reliability is "pending"
  await transport.ready;

  if (transport.reliability == "reliable-only") {
    // Use connection only with reliable transports
  } else {
    // Use connection with either reliable or unreliable transports.
  }
  // ...
}

Specifications

Specification
WebTransport
# dom-webtransport-reliability

Browser compatibility

BCD tables only load in the browser