WordPress: How to stop using unnecessary Jetpack CSS file
Since the last update of the popular WordPress plugin Jetpack there is some issue with its CSS file. Jetpack issue a separate CSS file at the frontend which takes extra 53 Kbyte. This is unnecessary for the contact, for the additional gallery styles etc.
If you can get rid of this unnecessary file this will save your page size and speed up load time. Long story short, If you want to suppress the output of the extra Jetpack CSS file simply put this following command at functions.php of the active theme:
// Remove Jetpack CSS
add_filter ('jetpack_implode_frontend_css', '__return_false');