截至2022年，MaxMind国家数据库可如下使用:

<?php
require_once 'vendor/autoload.php';
use MaxMind\Db\Reader;
$databaseFile = 'GeoIP2-Country.mmdb';
$reader = new Reader($databaseFile);
$cc = $reader->get($_SERVER['REMOTE_ADDR'])['country']['iso_code'] # US/GB...
$reader->close();

来源: https://github.com/maxmind/MaxMind-DB-Reader-php

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

我尝试了Chandra的答案，但我的服务器配置不允许file_get_contents()

PHP警告:file_get_contents() URL文件访问在服务器配置中被禁用

我修改了Chandra的代码，使它也适用于使用cURL的服务器:

function ip_visitor_country()
{

    $client  = @$_SERVER['HTTP_CLIENT_IP'];
    $forward = @$_SERVER['HTTP_X_FORWARDED_FOR'];
    $remote  = $_SERVER['REMOTE_ADDR'];
    $country  = "Unknown";

    if(filter_var($client, FILTER_VALIDATE_IP))
    {
        $ip = $client;
    }
    elseif(filter_var($forward, FILTER_VALIDATE_IP))
    {
        $ip = $forward;
    }
    else
    {
        $ip = $remote;
    }
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, "http://www.geoplugin.net/json.gp?ip=".$ip);
    curl_setopt($ch, CURLOPT_HEADER, 0);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);
    $ip_data_in = curl_exec($ch); // string
    curl_close($ch);

    $ip_data = json_decode($ip_data_in,true);
    $ip_data = str_replace('"', '"', $ip_data); // for PHP 5.2 see stackoverflow.com/questions/3110487/

    if($ip_data && $ip_data['geoplugin_countryName'] != null) {
        $country = $ip_data['geoplugin_countryName'];
    }

    return 'IP: '.$ip.' # Country: '.$country;
}

echo ip_visitor_country(); // output Coutry name

?>

希望能有所帮助;-)

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

实际上，您可以调用http://api.hostip.info/?ip=123.125.114.144来获取以XML形式显示的信息。

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 )

?>