PHP URL Encoding / Decoding

Question

I used the solution accepted for this question for encrypting by id for example in /index.php?id=3 . The problem is I cannot send the encrypted value as an

Answer 1

If you use Base64 to encode the binary value for the URL, there is also a variant with URL and filename safe alphabet.

You can use the strtr function to translate one from alphabet to the other:

$base64url = strtr($base64, '+/', '-_');
$base64 = strtr($base64url, '-_', '+/');

So you can use these functions to encode and decode base64url:

function base64url_encode($str) {
    return strtr(base64_encode($str), '+/', '-_'));
}
function base64url_decode($base64url) {
    return base64_decode(strtr($base64url, '-_', '+/'));
}

See also my answer on What is a good way to produce an short alphanumeric string from a long md5 hash?