免費介面如下：

$.getScript('http://int.dpool.sina.com.cn/iplookup/iplookup.php?format=js', function() {
    $("#depcity").val(getCity(remote_ip_info.city));
  
});

var remote_ip_info = {"ret":1,"start":-1,"end":-1,"country":"\u4e2d\u56fd","province":"\u6c5f\u82cf","city":"\u5f90\u5dde","district":"","isp":"","type":"","desc":""};
 

百度免費介面：

http://api.map.baidu.com/location/ip?ak=F454f8a5efe5e577997931cc01de3974&ip=180.124.234.248

ip：ip地址

響應結果：

{
    "address":"CN|江蘇|徐州|None|CHINANET|0|0",
    "content":{
        "address_detail":{
            "province":"江蘇省",
            "city":"徐州市",
            "district":"",
            "street":"",
            "street_number":"",
            "city_code":316
        },
        "address":"江蘇省徐州市",
        "point":{
            "y":"4041039.6",
            "x":"13045462.3"
        }
    },
    "status":0
}