Using emoji on a website, whether necessary or not. Many people argue about something similar for a resource. Let's start with the main thing, Google started blocking emoticons, arrows and the like in search results a long time ago. Although occasionally some characters can still be seen in the headings. 

Where to get and how to use emoji correctly, so as not to go into complexity, go to the site  in the search and write what you need to find. By the way, I advise you to look for different names. Next, we copy the HTML or CSS code, but before that we check how it is displayed on the above site. If the square next to the icon is not filled in, then your resource will not be displayed normally in any browser. 

The use of various kinds of symbols on a website is probably only necessary for certain topics. Sometimes you go to a resource and it hurts your eyes. It’s somehow understandable in the comments, people want to express their emotions, but when there are a million emoticons in the posts, it’s just annoying.

For visual perception of pages one at a time near the header there may be. For example, a company provides services: a wrench on one page, a car on another. But to be honest, there is a lot missing, and the icon font  is much better in this regard. 

You can use emoji on the site, the main thing is to put them a little, and in the subject ;)