ua-parser-js
Detect Browser, Engine, OS, CPU, and Device type/model from User-Agent data. Supports browser & node.js environment
fiftyone.devicedetection
Parse HTTP headers to detect the device type, model, operating system, browser, and crawler information
uadetect
The dead-simple way of interacting with the navigator API
isbot-fast
JavaScript module detecting bots/crawlers/spiders via user-agent
ua2os
Detect the OS from a User-Agent string.