Webcam in the browser example - https://codepen.io/zachberry/pen/gjyajp

webcam.js

// Copy this code and paste it in a dev tools console - Must be on an HTTPS site (or localhost)

document.write("<video></video>");

navigator.getUserMedia(
	{ video: true }, // Ask for video
	onGetUserMediaSuccess,
	onError
);

function onError(e) { console.error(e) }

function onGetUserMediaSuccess() {
	navigator.mediaDevices.enumerateDevices().then(devices => {
		devices.forEach(device => {
			if (device.kind === "videoinput") {
				console.log(device); // InputDeviceInfo { deviceId, label, ...}
				getStream(device.deviceId);
			}
		});
	});
}

function getStream(id) {
	if (!id) return;

	let constraints = { deviceId: { exact: id } };
	navigator.getUserMedia(
		{ video: constraints },
		onGetDeviceSuccess,
		onError
	);
}

function onGetDeviceSuccess(stream) {
	console.log(stream); //MediaStream
	let videoEl = document.getElementsByTagName('video')[0]
	videoEl.srcObject = stream;
	videoEl.play();
}