MediaWiki:Common.js

function CustomizeModificationsOfSidebar() {
    var toolbar = document.getElementById('p-tb');
    toolbar.parentNode.removeChild(toolbar);
    var accueil = document.getElementById('p-Menu_de_navigation');
    accueil.parentNode.removeChild(accueil);
}

if ( mw.config.get( 'wgUserId') == null ) {
    jQuery( CustomizeModificationsOfSidebar );
}