What are the javascript libraries that add step-by-step animation to the site?

Question

css

There was a need to add a small animation to the site. For example, a visitor enters the site, a picture appears smoothly, a site header appears with navigation, and some more animation.
Are there libraries that do without timeouts, but on promises, for example? If you do it yourself on promises, then how to catch Resolve during CSS animation? Count seconds?

Answer 1

wow.js and its analogues

Answer 2

how to catch Resolve on css animation?

The transitionend event on an element with animation.