Are WordPress Plugins JavaScript?

WordPress plugins are written in JavaScript. This makes them able to interact with the WordPress core and other plugins, as well as with the WordPress site itself.

This can give plugins a lot of power and flexibility.

However, JavaScript is not the only language that WordPress plugins can be written in. There are also PHP and Ruby plugins available, as well as a few written in other languages.

Ultimately, the language a plugin is written in is up to the author.