Available in Chrome 87+ | View on GitHub | Browse Samples
The Web Bluetooth API lets websites discover and communicate with devices over the Bluetooth 4 wireless standard using the Generic Attribute Profile (GATT). It is currently partially implemented in Android M, Chrome OS, Mac, and Windows 10.
This sample illustrates the use of the Web Bluetooth API to check if a permitted Bluetooth device is in range of the system before attempting to connect to the Bluetooth device. You may want to check out the Watch Advertisements sample.
async function onConnectToBluetoothDevicesButtonClick() {
try {
log('Getting existing permitted Bluetooth devices...');
const devices = await navigator.bluetooth.getDevices();
log('> Got ' + devices.length + ' Bluetooth devices.');
// These devices may not be powered on or in range, so scan for
// advertisement packets from them before connecting.
for (const device of devices) {
connectToBluetoothDevice(device);
}
}
catch(error) {
log('Argh! ' + error);
}
}
async function connectToBluetoothDevice(device) {
const abortController = new AbortController();
device.addEventListener('advertisementreceived', async (event) => {
log('> Received advertisement from "' + device.name + '"...');
// Stop watching advertisements to conserve battery life.
abortController.abort();
log('Connecting to GATT Server from "' + device.name + '"...');
try {
await device.gatt.connect()
log('> Bluetooth device "' + device.name + ' connected.');
}
catch(error) {
log('Argh! ' + error);
}
}, { once: true });
try {
log('Watching advertisements from "' + device.name + '"...');
await device.watchAdvertisements({ signal: abortController.signal });
}
catch(error) {
log('Argh! ' + error);
}
}
async function onRequestBluetoothDeviceButtonClick() {
try {
log('Requesting any Bluetooth device...');
const device = await navigator.bluetooth.requestDevice({
// filters: [...] <- Prefer filters to save energy & show relevant devices.
acceptAllDevices: true
});
log('> Requested ' + device.name);
}
catch(error) {
log('Argh! ' + error);
}
}