Magento 1 : Hide other shipping methods when free shipping is available

To prevent other shipping options to display when Free Shipping is available, add the following code to your template:



Open :
/app/design/frontend/[Your_package]/[Your_theme]/template/checkout/onepage/shipping_method/available.phtml

<?php
if ( array_key_exists('freeshipping', $_shippingRateGroups )) {
unset($_shippingRateGroups["flatrateperproduct"]);
}
?>

Then ,  flatrateperproduct Method will be remove from the shipping method.