You Don’t Need jQuery is a GitHub repository with a collection of code snippets that show how to do the most common jQuery bits in native JavaScript. The collection covers a whole range of subjects, like:
- Query selector
- CSS and style
- DOM manipulation
- AJAX
- Events
- Promises
- Animations
- … and more.
All examples should work just fine in all modern browsers.
Additionally, have a look at the You Might Not Need jQuery website.