bowser
Lightweight browser detector
esniff
Low footprint ECMAScript source code parser
url-regex-safe
Regular expression matching for URL's. Maintained, safe, and browser-friendly version of url-regex. Resolves CVE-2020-7661. Works in Node v10.12.0+ and browsers.
mobile-detect
Device detection (phone, tablet, desktop, mobile grade, os, versions)
bowser-ultralight
Lightweight(er) browser detector, basically a trimmed down version of bowser, specfically made for Atlassian