redir.html

<!DOCTYPE html>
<html lang="en-US">
    <head>
        <meta charset="UTF-8" />
        <meta
            http-equiv="refresh"
            content="0;
                       url=%(new)s.html"
            />
        <script type="text/javascript">
            window.location.href = '%(new)s';
        </script>
        <title>Your Site Title Here</title>
    </head>
    <body>
        If you are not redirected automatically, follow this
        <a href="%(new)s">link</a>.
    </body>
</html>