ua-parser-js
Detect Browser, Engine, OS, CPU, and Device type/model from User-Agent & Client Hints data. Supports browser & node.js environment
environment
Check which JavaScript environment your code is running in at runtime: browser, Node.js, Bun, etc
bowser
Lightweight browser detector
modernizr
Modernizr is a JavaScript library that detects HTML5 and CSS3 features in the user’s browser.