Look at this question link . One of the responses recommends using WebRTC. Chrome on iOS, Internet Explorer and Safari have not implemented WebRTC yet.
WebRTC has a bug that makes it possible for you to obtain a user's IP even if you are using a VPN (virtual private network). In other words, this failure can be corrected someday and once corrected this method will no longer work. It is also possible to disable the WebRTC in Firefox, so you will not be able to obtain the IP of those users. Here you can try your browser link
The simplified code in that answer that only gives you an IP is:
var findIP = new Promise(r=>{var w=window,a=new (w.RTCPeerConnection||w.mozRTCPeerConnection||w.webkitRTCPeerConnection)({iceServers:[]}),b=()=>{};a.createDataChannel("");a.createOffer(c=>a.setLocalDescription(c,b,b),b);a.onicecandidate=c=>{try{c.candidate.candidate.match(/([0-9]{1,3}(\.[0-9]{1,3}){3}|[a-f0-9]{1,4}(:[a-f0-9]{1,4}){7})/g).forEach(r)}catch(e){}}})
/*Ejemplo de uso*/
findIP.then(ip => document.write('Tu IP: ', ip)).catch(e => console.error(e))
The code that can give you several IP of the user depending on your network is:
function findIP(onNewIP) { // onNewIp - your listener function for new IPs
var myPeerConnection = window.RTCPeerConnection || window.mozRTCPeerConnection || window.webkitRTCPeerConnection; //compatibility for firefox and chrome
var pc = new myPeerConnection({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 ipIterate(ip) {
if (!localIPs[ip]) onNewIP(ip);
localIPs[ip] = true;
}
pc.createDataChannel(""); //create a bogus data channel
pc.createOffer(function(sdp) {
sdp.sdp.split('\n').forEach(function(line) {
if (line.indexOf('candidate') < 0) return;
line.match(ipRegex).forEach(ipIterate);
});
pc.setLocalDescription(sdp, noop, noop);
}, noop); // create offer and set local description
pc.onicecandidate = function(ice) { //listen for candidate events
if (!ice || !ice.candidate || !ice.candidate.candidate || !ice.candidate.candidate.match(ipRegex)) return;
ice.candidate.candidate.match(ipRegex).forEach(ipIterate);
};
}
var ul = document.createElement('ul');
ul.textContent = 'Your IPs are: '
document.body.appendChild(ul);
function addIP(ip) {
console.log('got ip: ', ip);
var li = document.createElement('li');
li.textContent = ip;
ul.appendChild(li);
}
findIP(addIP);
The original code is from link