你可以使用ipstack地理API获取访问者国家和城市。你需要获得自己的ipstack API，然后使用下面的代码:

<?php
 $ip = $_SERVER['REMOTE_ADDR']; 
 $api_key = "YOUR_API_KEY";
 $freegeoipjson = file_get_contents("http://api.ipstack.com/".$ip."?access_key=".$api_key."");
 $jsondata = json_decode($freegeoipjson);
 $countryfromip = $jsondata->country_name;
 echo "Country: ". $countryfromip ."";
?>

来源:使用ipstack API在PHP中获取访问者国家和城市

由CPAN的Perl社区维护的ip->国家数据库有一个维护良好的平面文件版本

访问这些文件不需要数据服务器，数据本身大约是515k

Higemaru编写了一个PHP包装器来处理这些数据:PHP -ip-country-fast

试试这个简单的PHP函数。

<?php

function ip_info($ip = NULL, $purpose = "location", $deep_detect = TRUE) {
    $output = NULL;
    if (filter_var($ip, FILTER_VALIDATE_IP) === FALSE) {
        $ip = $_SERVER["REMOTE_ADDR"];
        if ($deep_detect) {
            if (filter_var(@$_SERVER['HTTP_X_FORWARDED_FOR'], FILTER_VALIDATE_IP))
                $ip = $_SERVER['HTTP_X_FORWARDED_FOR'];
            if (filter_var(@$_SERVER['HTTP_CLIENT_IP'], FILTER_VALIDATE_IP))
                $ip = $_SERVER['HTTP_CLIENT_IP'];
        }
    }
    $purpose    = str_replace(array("name", "\n", "\t", " ", "-", "_"), NULL, strtolower(trim($purpose)));
    $support    = array("country", "countrycode", "state", "region", "city", "location", "address");
    $continents = array(
        "AF" => "Africa",
        "AN" => "Antarctica",
        "AS" => "Asia",
        "EU" => "Europe",
        "OC" => "Australia (Oceania)",
        "NA" => "North America",
        "SA" => "South America"
    );
    if (filter_var($ip, FILTER_VALIDATE_IP) && in_array($purpose, $support)) {
        $ipdat = @json_decode(file_get_contents("http://www.geoplugin.net/json.gp?ip=" . $ip));
        if (@strlen(trim($ipdat->geoplugin_countryCode)) == 2) {
            switch ($purpose) {
                case "location":
                    $output = array(
                        "city"           => @$ipdat->geoplugin_city,
                        "state"          => @$ipdat->geoplugin_regionName,
                        "country"        => @$ipdat->geoplugin_countryName,
                        "country_code"   => @$ipdat->geoplugin_countryCode,
                        "continent"      => @$continents[strtoupper($ipdat->geoplugin_continentCode)],
                        "continent_code" => @$ipdat->geoplugin_continentCode
                    );
                    break;
                case "address":
                    $address = array($ipdat->geoplugin_countryName);
                    if (@strlen($ipdat->geoplugin_regionName) >= 1)
                        $address[] = $ipdat->geoplugin_regionName;
                    if (@strlen($ipdat->geoplugin_city) >= 1)
                        $address[] = $ipdat->geoplugin_city;
                    $output = implode(", ", array_reverse($address));
                    break;
                case "city":
                    $output = @$ipdat->geoplugin_city;
                    break;
                case "state":
                    $output = @$ipdat->geoplugin_regionName;
                    break;
                case "region":
                    $output = @$ipdat->geoplugin_regionName;
                    break;
                case "country":
                    $output = @$ipdat->geoplugin_countryName;
                    break;
                case "countrycode":
                    $output = @$ipdat->geoplugin_countryCode;
                    break;
            }
        }
    }
    return $output;
}

?>

使用方法:

Example1:获取访问者IP地址的详细信息

<?php

echo ip_info("Visitor", "Country"); // India
echo ip_info("Visitor", "Country Code"); // IN
echo ip_info("Visitor", "State"); // Andhra Pradesh
echo ip_info("Visitor", "City"); // Proddatur
echo ip_info("Visitor", "Address"); // Proddatur, Andhra Pradesh, India

print_r(ip_info("Visitor", "Location")); // Array ( [city] => Proddatur [state] => Andhra Pradesh [country] => India [country_code] => IN [continent] => Asia [continent_code] => AS )

?>

例2:获取任意IP地址的详细信息。[支持IPV4和IPV6]

<?php

echo ip_info("173.252.110.27", "Country"); // United States
echo ip_info("173.252.110.27", "Country Code"); // US
echo ip_info("173.252.110.27", "State"); // California
echo ip_info("173.252.110.27", "City"); // Menlo Park
echo ip_info("173.252.110.27", "Address"); // Menlo Park, California, United States

print_r(ip_info("173.252.110.27", "Location")); // Array ( [city] => Menlo Park [state] => California [country] => United States [country_code] => US [continent] => North America [continent_code] => NA )

?>

PHP代码获取国家，城市， 大陆等使用IP地址

    $ip = $_SERVER["REMOTE_ADDR"];
      
    // Use JSON encoded string and converts 
    // it into a PHP variable 
    $ipdat = @json_decode(file_get_contents( 
        "http://www.geoplugin.net/json.gp?ip=" . $ip)); 
       
    $country = $ipdat->geoplugin_countryName; 
    $city = $ipdat->geoplugin_city; 
    $continent_name = $ipdat->geoplugin_continentName; 
    $latitude = $ipdat->geoplugin_latitude; 
    $longitude = $ipdat->geoplugin_longitude; 
    $currency_symbol = $ipdat->geoplugin_currencySymbol; 
    $currency_code = $ipdat->geoplugin_currencyCode; 
    $timezone = $ipdat->geoplugin_timezone; 

不确定这是否是一个新的服务，但现在(2016)在php中最简单的方法是使用geoplugin的php web服务:http://www.geoplugin.net/php.gp:

基本用法:

// GET IP ADDRESS
if (!empty($_SERVER['HTTP_CLIENT_IP'])) {
    $ip = $_SERVER['HTTP_CLIENT_IP'];
} else if (!empty($_SERVER['HTTP_X_FORWARDED_FOR'])) {
    $ip = $_SERVER['HTTP_X_FORWARDED_FOR'];
} else if (!empty($_SERVER['REMOTE_ADDR'])) {
    $ip = $_SERVER['REMOTE_ADDR'];
} else {
    $ip = false;
}

// CALL THE WEBSERVICE
$ip_info = unserialize(file_get_contents('http://www.geoplugin.net/php.gp?ip='.$ip));

它们还提供了一个现成的类:http://www.geoplugin.com/_media/webservices/geoplugin.class.php.tgz?id=webservices%3Aphp&cache=cache

使用以下服务

1) http://api.hostip.info/get_html.php?ip=12.215.42.19

2)

$json = file_get_contents('http://freegeoip.appspot.com/json/66.102.13.106');
$expression = json_decode($json);
print_r($expression);

3) http://ipinfodb.com/ip_location_api.php