How do you detect a website visitor’s country?

There are some free services out there in the Internet which let you find country and IP-based geolocalization from the client-side IP data.

wipmania is a free JSONP service which can be used to determine visitor’s country. It’s really simple to use:

<script type="text/javascript">
  // plain JavaScript example
  function jsonpCallback(data) { 
    alert('Latitude: ' + data.latitude + 
          '\nLongitude: ' + data.longitude + 
          '\nCountry: ' + data.address.country); 
 }
</script>

<script src="http://api.wipmania.com/jsonp?callback=jsonpCallback"
        type="text/javascript"></script>

if you use a framework that supports JSONP, like jQuery, you can use:

// jQuery example
$.getJSON('http://api.wipmania.com/jsonp?callback=?',
  function (data) { 
  alert('Latitude: ' + data.latitude + 
        '\nLongitude: ' + data.longitude + 
        '\nCountry: ' + data.address.country); 
});

Check the above snippet running here.

Instead of an alert dialog (as in the above example), if you want to redirect a URL that takes a US visitor to a .COM address and allows a Canadian visitor passes through normally (for a .ca version of a website with a sister .com version site), simply use a “switch” statement in the “onload” event, check the “country” returned from the json function, then call Server.Transfer (asp.net) or similiar.