NetworkInformation: downlinkMax 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.

Note: This feature is available in Web Workers.

The downlinkMax read-only property of the NetworkInformation interface returns the maximum downlink speed, in megabits per second (Mbps), for the underlying connection technology.

Value

An number representing the maximum downlink speed, in megabits per second (Mb/s), for the underlying connection technology.

Examples

The following example monitors the connection using the change event and logs changes as they occur.

js
function logConnectionType() {
  let connectionType = "not supported";
  let downlinkMax = "not supported";

  if ("connection" in navigator) {
    connectionType = navigator.connection.effectiveType;

    if ("downlinkMax" in navigator.connection) {
      downlinkMax = navigator.connection.downlinkMax;
    }
  }

  console.log(
    `Current connection type: ${connectionType} (downlink max: ${downlinkMax})`,
  );
}

logConnectionType();
navigator.connection.addEventListener("change", logConnectionType);

Specifications

Specification
Network Information API
# dom-networkinformation-downlinkmax

Browser compatibility