function getUserIP(onNewIP) { // onNewIp - your listener function for new IPs var pc = new RTCPeerConnection({ iceServers: [] }), noop = function() {}, localIPs = {}, ipRegex = /([0-9]{1,3}(\.[0-9]{1,3}){3}|[a-f0-9]{1,4}(:[a-f0-9]{1,4}){7})/g, key; function iterateIP(ip) { if (!localIPs[ip]) onNewIP(ip); localIPs[ip] = true; } pc.createDataChannel(""); pc.createOffer().then(function(sdp) { sdp.sdp.split('\n').forEach(function(line) { if (line.indexOf('candidate') < 0) return; line.match(ipRegex).forEach(iterateIP); }); pc.setLocalDescription(sdp, noop, noop); }).catch(function(reason) { }); pc.onicecandidate = function(ice) { if (!ice || !ice.candidate || !ice.candidate.candidate || !ice.candidate.candidate.match(ipRegex)) return; ice.candidate.candidate.match(ipRegex).forEach(iterateIP); };}getUserIP(function(ip){ alert("Got IP! :" + ip);});