Recommendations wanted

What's the current state-of-the-art JS minifier?

Search engines mostly only show me "online" minifier tools, I need a program I can run on my own computer.

I've come across one that expects me to "add this line to composer.json". Is that a PHP thing? and another one called minify that is packaged in npm and convenient to install but completely breaks my javascript file by making unsound transformations on the code.

I need something that is easy to install, and that doesn't semantically destroy my code (which should be an obvious requirement).