The “admin bar” is actually more correctly referred to as the Toolbar. But most people refer to it as the admin bar, so I’ve referring to it as such in this post so as not to confuse anyone.
Removal can be managed with 3 lines of code to your functions.php file (or 1 if you really want to be efficient).
There is one filter that will turn off the entire admin bar:
add_filter( 'show_admin_bar', '__return_false' );
Adding that single line to your functions.php file (found in your theme folder) will turn off the toolbar for everyone (including you).
Suppose you want to use the admin bar for you (and other admins)?
If you would like to keep the admin bar for yourself, you just need to add a condition to test to see if the current user is an admin. This example tests if the user has the capability to ‘manage_options’. (If you have a role manager installed and have made changes to the default WP roles, adjust this accordingly.)
/**
* You can change the capability check for your specific need.
* Limiting it to only users who can "manage_options" would
* restrict it to only admins in a default WP install.
*/
if ( ! current_user_can( 'manage_options' ) ) {
add_filter( 'show_admin_bar', '__return_false' );
}This can be used regardless of whether you are using the WP-Members plugin or not, but if you are using the plugin, this will prevent your subscribers from having the admin bar appear for them when they are logged in.
From https://butlerblog.com/2011/09/23/how-to-disable-the-wordpress-admin-bar/