To center a popup window on the screen, you can try to run the following code
Example
Live Demo
<!DOCTYPE html> <html> <body> <script> function myPopup(myURL, title, myWidth, myHeight) { var left = (screen.width - myWidth) / 2; var top = (screen.height - myHeight) / 4; var myWindow = window.open(myURL, title, 'toolbar=no, location=no, directories=no, status=no, menubar=no, scrollbars=no, resizable=no, copyhistory=no, width=' + myWidth + ', height=' + myHeight + ', top=' + top + ', left=' + left); } </script> <button onclick=" myPopup ('https://www.qries.com', 'web', 1050, 550);">Open Qries.com</button> </body> </html>