WordPress.org

Codex

Plugin API/Filter Reference/login head

The login_head filter can be used to filter the logo image on the WordPress login page. By default this logo is of WordPress.

Note: this is not the only possible use of this filter. It can be used to add anything to the <head> section on the login page.

Usage

<?php add_filter( 'login_head', 'custom_function_name' ); ?> Where "custom_function_name" is the function to be called when the content is being retrieved.

Example

In the below example the default logo is changed to custom logo, using CSS. 

<?php

function my_custom_login_logo() {
    echo '<style type="text/css">
	h1 a {background-image:url(http://example.com/your-logo.png) !important; margin:0 auto;}
	</style>';
}
add_filter( 'login_head', 'my_custom_login_logo' );

?>
This page is marked as incomplete. You can help Codex by expanding it.
Retrieved from "http://codex.wordpress.org/Plugin_API/Filter_Reference/login_head"

Codex Resources