RFC 2616 - Section 3 states: "Servers should be cautious about depending on URI lengths above 255 bytes because some older client or proxy implementations may not properly support these lengths." Different browser agents support different URI length acceptance. In addition, servers too play a role in accepting/denying URI's over certain length which may either truncate the URI or may give lengthy URI message indications. It is always advisable to rely on shorter URI's and to post data when more field sets are to be transferred across web pages. POST data too has its limit. In this case, it is the size of the data which is controlled by the server settings. Some interesting discussions: Limit on query string GET URL parameters

PHP program to pass data as GET parameters

<?php
// PHP 5 how to pass data as a query string
/*
http_build_query is a function in PHP 5 that enables you to URL encode the query string. You can pass an array or an array of array to this function. The default separator is "&"
*/

$data = array("first_name" => "Robert",
                "last_name" => "Brown",
                "address" => "123 Adam St., New York"
            );

// URI formatted with character encoding
$pass_string = "http://localhost/demo.php?".http_build_query($data, '');

echo "<h2>Query URI (using http_build_query)</h2><br />";
echo $pass_string;            
?>

Ouput from the above execution: Query URI (using http_build_query) http://localhost/demo.php?first_name=Robert&last_name=Brown&address=123+Adam+St.%2C+New+York