Easiest way

<?php 
//-- you can modified it like you want

echo $width = "<script>document.write(screen.width);</script>";
echo $height = "<script>document.write(screen.height);</script>";

?>

This is a very simple process. Yes, you cannot get the width and height in PHP. It is true that JQuery can provide the screen's width and height. First go to https://github.com/carhartl/jquery-cookie and get jquery.cookie.js. Here is example using php to get the screen width and height:

    <!DOCTYPE html>
    <html lang="en">
    <head>
        <meta charset="UTF-8">
        <title>Test</title>
        <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
        <script src="https://ajax.googleapis.com/ajax/libs/jqueryui/1.12.1/jquery-ui.min.js"></script>
        <script src="js/jquery.cookie.js"></script>
        <script type=text/javascript>
            function setScreenHWCookie() {
                $.cookie('sw',screen.width);
                $.cookie('sh',screen.height);
                return true;
            }
            setScreenHWCookie();
        </script>
    </head>
    <body>
        <h1>Using jquery.cookie.js to store screen height and width</h1>
    <?php
         if(isset($_COOKIE['sw'])) { echo "Screen width: ".$_COOKIE['sw']."<br/>";}
         if(isset($_COOKIE['sh'])) { echo "Screen height: ".$_COOKIE['sh']."<br/>";}
    ?>
    </body>
    </html>

I have a test that you can execute: http://rw-wrd.net/test.php

You can check it like below:

if(strstr(strtolower($_SERVER['HTTP_USER_AGENT']), 'mobile') || strstr(strtolower($_SERVER['HTTP_USER_AGENT']), 'android')) {
   echo "mobile web browser!";
} else {
echo "web browser!";
}

Fully Working Example

I couldn't find an actual working PHP example to "invisibly" (without URL parameters) return client screen size, and other properties, to server-side PHP, so I put this example together.

JS populates and submits a hidden form (scripted by PHP from an array of JS properties), POSTing to itself (the data now available in PHP) and returns the data in a table.

_{(Tested in "several" browsers.)}

<!DOCTYPE html>
<html>
<head>
    <title>*Client Info*</title>
    <style>table,tr{border:2px solid gold;border-collapse:collapse;}td{padding:5px;}</style>
</head>

<body>
<?php
  $clientProps=array('screen.width','screen.height','window.innerWidth','window.innerHeight', 
    'window.outerWidth','window.outerHeight','screen.colorDepth','screen.pixelDepth');

  if(! isset($_POST['screenheight'])){

    echo "Loading...<form method='POST' id='data' style='display:none'>";
    foreach($clientProps as $p) {  //create hidden form
      echo "<input type='text' id='".str_replace('.','',$p)."' name='".str_replace('.','',$p)."'>";
    }
    echo "<input type='submit'></form>";

    echo "<script>";
    foreach($clientProps as $p) {  //populate hidden form with screen/window info
      echo "document.getElementById('" . str_replace('.','',$p) . "').value = $p;";
    }
    echo "document.forms.namedItem('data').submit();"; //submit form
    echo "</script>";

  }else{

    echo "<table>";
    foreach($clientProps as $p) {   //create output table
      echo "<tr><td>".ucwords(str_replace('.',' ',$p)).":</td><td>".$_POST[str_replace('.','',$p)]."</td></tr>";
    }
    echo "</table>";
  }
?>
<script>
    window.history.replaceState(null,null); //avoid form warning if user clicks refresh
</script>
</body>
</html>

The returned data is extract'd into variables. For example:

• window.innerWidth is returned in $windowinnerWidth

You can set window width in cookies using JS in front end and you can get it in PHP:

<script type="text/javascript">
   document.cookie = 'window_width='+window.innerWidth+'; expires=Fri, 3 Aug 2901 20:47:11 UTC; path=/';
</script>

<?PHP
    $_COOKIE['window_width'];
?>

Here is the Javascript Code: (index.php)

<script>
    var xhttp = new XMLHttpRequest();  
    xhttp.open("POST", "/sqldb.php", true);
    xhttp.send("screensize=",screen.width,screen.height);
</script>

Here is the PHP Code: (sqldb.php)

$data = $_POST['screensize'];
$pdo = new PDO('mysql:host=localhost;dbname=test', 'username', 'password');
$statement = $pdo->prepare("UPDATE users SET screen= :screen WHERE id = $userid");
$statement->execute(array('screen' => $data));

I hope that you know how to get the $userid from the Session, and for that you need an Database with the Table called users, and an Table inside users called screen ;=) Regards KSP

The quick answer is no, then you are probably asking why can't I do that with php. OK here is a longer answer. PHP is a serverside scripting language and therefor has nothing to do with the type of a specific client. Then you might ask "why can I then get the browser agent from php?", thats because that information is sent with the initial HTTP headers upon request to the server. So if you want client information that's not sent with the HTTP header you must you a client scripting language like javascript.

For get the width screen or the height screen
1- Create a PHP file (getwidthscreen.php) and write the following commands in it
PHP (getwidthscreen.php)

<div id="widthscreenid"></div>
<script>
document.getElementById("widthscreenid").innerHTML=screen.width;
</script>

2- Get the width screen through a cURL session by the following commands
PHP (main.php)

$ch = curl_init( 'http://hostname/getwidthscreen.php' );
curl_setopt( $ch, CURLOPT_RETURNTRANSFER, true );
$result = curl_exec( $ch );
print_r($result);
curl_close( $ch );