WebTransport: reliability property

Limited availability

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

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.

Note: This feature is available in Web Workers.

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).

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

Report problems with this compatibility data on GitHub
desktopmobileserver
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
Deno
reliability
Experimental

Legend

Tip: you can click/tap on a cell for more information.

Full support
Full support
No support
No support
Experimental. Expect behavior to change in the future.
User must explicitly enable this feature.