demo · v130

RFCOMM Device Explorer

Chrome 130 adds SerialPort.connected (whether a previously-paired Bluetooth RFCOMM device is in range) and new connect/disconnect events on navigator.serial for Bluetooth RFCOMM ports. This explorer lists real granted serial ports and reports the browser's live connected state.

Checking Web Serial API availability…
Paired serial devices 0 devices
No devices paired yet. Click "Request serial port" or "List paired ports".
Event log — connect / disconnect / rfcomm events
—Waiting for events…

Chrome 130 additions

SerialPort.connected
Read-only boolean: true if the port is a Bluetooth RFCOMM port and the device is currently connected/in range — without opening the port.
New in Chrome 130 ✓
navigator.serial "connect" event
Fires when a previously-paired Bluetooth RFCOMM device comes into range. Allows proactive reconnection logic without polling.
New in Chrome 130 ✓
navigator.serial "disconnect" event
Fires when an RFCOMM device goes out of range. Allows graceful cleanup before the next open() attempt fails.
New in Chrome 130 ✓
Wired USB/CDC serial
connect/disconnect events already existed for wired USB serial devices in earlier Chrome versions via USBDevice tracking.
Pre-existing
// Chrome 130: SerialPort.connected + RFCOMM events

// Check if a paired Bluetooth device is in range
const ports = await navigator.serial.getPorts();
for (const port of ports) {
  if (port.connected) {
    console.log('Device in range:', port);  // ← Chrome 130
  }
}

// Listen for RFCOMM devices coming/going
navigator.serial.addEventListener('connect', event => {
  console.log('RFCOMM device appeared:', event.port);
  // event.port.connected === true
});

navigator.serial.addEventListener('disconnect', event => {
  console.log('RFCOMM device went away:', event.port);
  // event.port.connected === false
  cleanupPort(event.port);
});

// Open only when connected
if (port.connected) {
  await port.open({ baudRate: 9600 });
} else {
  // Wait for the 'connect' event instead of polling
}

see also