Something is wrong. But now working fine

cookie1.php

<?php
if (isset($_COOKIE['counter'])) {
    $counter = $_COOKIE['counter'];
    echo $counter;
    $counter++;
    setcookie('counter', $counter, time() + 60*60*24*30, '/', '', false, true);
} else {
    setcookie('counter', 1, time() + 60*60*24*30, '/', '', false, true);
}

cookie2.php

<?php
if (isset($_COOKIE['counter'])) {
    $counter = $_COOKIE['counter'];
    if ($counter%2 == 0) {
        echo "Even";        
    } else {
        echo "Odd";        
    }
    echo $counter;
    $counter++;    
    setcookie('counter', $counter, time() + 60*60*24*30, '/', '', false, true);
} else {
    setcookie('counter', 1, time() + 60*60*24*30, '/', '', false, true);
}

Built in server cookie functionality

php -S localhost:8000 cookie1.php

When the code was cookie1.php I was getting cookie values multiples of 2 on each request. 2, 4, 6 etc.

So I made a check to see whether 2 request are going. But now it is again with the correct value. May be as https://twitter.com/f_u_e_n_t_e/status/466854136647270400 mentioned there may be some hidden request ?

What requests do you see in the console when running the php -S command? They should show up there.. otherwise, also open up the network tab in the debugger of your browser to see what requests are being done.

Keep in mind that all requests are routed to the file you point to as index (cookie1.php).
From the manual:

"If a PHP file is given on the command line when the web server is started it is treated as a "router" script. The script is run at the start of each HTTP request. If this script returns FALSE, then the requested resource is returned as-is. Otherwise the script's output is returned to the browser."

Favicon!

@m6w6 no favicon is here see the php script .

@ramondelafuente Yes the script was started with php -S . Sorry for the delay guyes, I missed to see the comments. I am not sure why gist comments are not mailed by github.