// Get the connection type.
    var type = navigator.connection.type;

    // Get an upper bound on the downlink speed of the first network hop
    var max = navigator.connection.downlinkMax;

    function changeHandler(e) {
      // Handle change to connection here.
    }

    // Register for event changes.
    navigator.connection.onchange = changeHandler;

    // Alternatively.
    navigator.connection.addEventListener('change', changeHandler);
  

bluetooth

A Bluetooth connection.

cellular

A cellular connection (e.g., EDGE, HSPA, LTE, etc.).

ethernet

An Ethernet connection.

none

No network connection. The user agent will not contact the network when the user follows links or when a script requests a remote page (or knows that such an attempt would fail) - i.e., equivalent to `navigator.onLine === false` in HTML.

mixed

The user agent is using multiple connection types.

other

The connection type that is known, but not one of enumerated connection types.

unknown

The user agent has established a network connection, but is unable, or unwilling, to determine the underlying connection technology.

wifi

A Wi-Fi connection.

wimax

A WiMAX connection.

  enum ConnectionType {
    "bluetooth",
    "cellular",
    "ethernet",
    "mixed",
    "none",
    "other",
    "unknown",
    "wifi",
    "wimax"
  };

  enum EffectiveConnectionType {
    "2g",
    "3g",
    "4g",
    "slow-2g"
  };

  [NoInterfaceObject, Exposed=(Window,Worker)]
  interface NavigatorNetworkInformation {
    readonly attribute NetworkInformation connection;
  };

  Navigator implements NavigatorNetworkInformation;
  WorkerNavigator implements NavigatorNetworkInformation;

  [Exposed=(Window,Worker)]
  interface NetworkInformation : EventTarget {
    readonly attribute ConnectionType type;
    readonly attribute EffectiveConnectionType effectiveType;
    readonly attribute Megabit downlinkMax;
    readonly attribute Megabit downlink;
    readonly attribute Millisecond rtt;
    attribute EventHandler onchange;
  };

  typedef unrestricted double Megabit;
  typedef unsigned long long Millisecond;