WordPress automatically loads this file wp-emoji-release.min.js on the front-end to help loading emojis that are part of the blogging feature of WordPress.While this is great for the users who need it, most developers and professional websites have no need for emojis on their site. This ofcourse can be easily ignored, as it is a small file. However, it is a script that is being loaded into your WordPress site, and does factor into the loading speed of your site, no matter how little is impact can be.

Quelle: Stop loading wp-emoji-release.min.js in your WordPress site