A core support for Emoji appeared in WordPress 4.2 release. It’s based on a Twemoji library, and the emoji typefaces are downloaded from WordPress.org server.
Why do users want to remove Emoji support in WordPress?
Mainly it happens when outer sources are forbidden (for instance, if a website is a part of intranet, or there are other high security requirements).
How can you remove emojis?
Use a Disable Emojis plugin. It was released at the same time when WordPress 4.2 was. The plugin doesn’t have any settings and it removes all scripts and styles of Twemoji library.
Disable Emojis plugin doesn’t change the database schema which, starting from version 4.2, supports utf8mb4 encoding, that’s why you still can save Emoji signs in posts and pages of WordPress, regardless of using this plugin or not. Keep in mind, not all browsers support Emoji.
You can get Disable Emojis for free on WordPress.org under GPL license.
How do you install the plugin?
Go to Dashboard → Plugins → Add new.