Just have found a good way to remove unnecessary css and js links on your website header. If you aren't familiar with a good page load auditor, you might visit Gtmetrix.com , Pingdom.com , and Google Page Speed to check your site's performance. Unused CSS and JS scripts makes your site's page load so heavy and sometimes it turns over 10 to 30 seconds to display your frontend on the browser. Thus, this way could also give you more idea on how do you manage your site's performance. I have tried several times the use of wp_dequeue_style() functions both in my child and parent theme but didn't worked. However, I never liked contact form 7 to run out in my front-end since before I get into Wordpress platform so I often removed it by adding code define( 'WPCF7_LOAD_CSS', false ) into wp-config.php just below define( 'WP_DEBUG', false ) . So let's get started. You must first check the running css on your front-end on browser element inspector. On