If you are using Emojis on your website they should be wrapped in a span tag, have role="img", and have an accessible description. This will provide an invisible label to users using devices such as screen reader.
<!-- This is much better --> <h1>Take off! <span role="img" aria-label="Space rocket">🚀</span></h1> <!-- than this --> <h1>Take off! 🚀</h1>