JS获取IP

搜狐接口

<script src="http://pv.sohu.com/cityjson?ie=utf-8"></script>
<script type="text/javascript">
  document.write(returnCitySN["cip"] + ',' + returnCitySN["cname"])
</script>

内网IP

原文地址：https://ourcodeworld.com/articles/read/257/how-to-get-the-client-ip-address-with-javascript-only

<script type="text/javascript">
  /**
   * Get the user IP throught the webkitRTCPeerConnection
   * @param onNewIP {Function} listener function to expose the IP locally
   * @return undefined
   */
  function getUserIP(onNewIP) { //  onNewIp - your listener function for new IPs
    //compatibility for firefox and chrome
    var myPeerConnection = window.RTCPeerConnection || window.mozRTCPeerConnection || window.webkitRTCPeerConnection;
    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 iterateIP(ip) {
      if (!localIPs[ip]) onNewIP(ip);
      localIPs[ip] = true;
    }

    //create a bogus data channel
    pc.createDataChannel("");

    // create offer and set local description
    pc.createOffer().then(function (sdp) {
      sdp.sdp.split('
').forEach(function (line) {
        if (line.indexOf('candidate') < 0) return;
        line.match(ipRegex).forEach(iterateIP);
      });

      pc.setLocalDescription(sdp, noop, noop);
    }).catch(function (reason) {
      // An error occurred, so handle the failure to connect
    });

    //listen for candidate events
    pc.onicecandidate = function (ice) {
      if (!ice || !ice.candidate || !ice.candidate.candidate || !ice.candidate.candidate.match(ipRegex)) return;
      ice.candidate.candidate.match(ipRegex).forEach(iterateIP);
    };
  }

  // Usage

  getUserIP(function (ip) {
    alert("Got IP! :" + ip);
  });
</script>