Change WordPress Logo on Admin Signup or Login Page

You can easily change the WordPress logo on the Login page with the help of  following PHP function. Copy the following code & place it in functions.php file of your active theme. Replace the url field with the file-name of your logo having appropriate path, and store your logo accordingly :

function admin_login_logo() { 
?> 
<style type="text/css"> 
body.login div#login h1 a {
 background-image: url(http://wesbsite.com/one.png);  
 //Add your own logo image in this url 
 padding-bottom: 10px; 
 height: auto !important;
 background-size:130px;
 width: 100%; 
} 
</style>
 <?php 
} 
add_action( 'login_enqueue_scripts', 'admin_login_logo' );