The web Google Maps API doesn't seem to offer an IP address geolocation service (the provided example suggests using the W3C Geolocation standard, which typically requires an action from the user).
However! Google's Maps Geolocation API, typically used on mobile clients, can be used from the web and does return a latitude & longitude based on the requesting client's IP address.
Here's a quick jQuery example that demonstrates its use:
$.ajax({
url: 'https://www.googleapis.com/geolocation/v1/geolocate?key=YOUR-API-KEY',
data: JSON.stringify({ "considerIp": "true" }),
type: 'POST',
contentType: 'application/json',
success: function(data) {
if(data.location) {
alert(data.location.lat + ', ' + data.location.lng);
} else {
alert('not found');
}
}
});
Here's the curl
equivalent:
curl -H "Content-Type: application/json" -X POST -d '{"considerIp": true}' https://www.googleapis.com/geolocation/v1/geolocate?key=YOUR-API-KEY
Don't forget to swap in a real API key in the examples above AND to enable the Geolocation API for your Google API project.