Browser Usage

Recommended: uaBrowser.detect()

detect() collects hardware signals on top of UA parsing and is the recommended browser-side entry point.

import uaBrowser from 'ua-browser'

const result = await uaBrowser.detect()

console.log(result.version)   // '149.0.7827.102' — real version, not the frozen UA value
console.log(result.osVersion) // '26.5.1' — real macOS version
console.log(result.device)    // 'Mobile' — correct even in desktop mode
console.log(result.arch)      // 'arm64' — Apple Silicon vs Intel

What detect() collects beyond the UA string:

Signal	Purpose
Client Hints fullVersionList	Real browser full version (not the frozen UA value)
Client Hints platformVersion	Real OS version (macOS 26+, Windows 10/11)
WebGL renderer	GPU model — distinguishes Apple Silicon / Intel / AMD / Qualcomm
CSS safe-area-inset	Detects iPhone notch / Dynamic Island, not spoofable by UA
Vibration / motion APIs	Distinguishes real mobile devices from desktop browsers faking mobile

Note: detect() relies on the Client Hints high-entropy API (getHighEntropyValues), which is only available in HTTPS or localhost contexts. On plain HTTP pages it degrades silently — browser version and OS version fall back to the frozen UA string values (e.g. Chrome reports 149.0.0.0, macOS 26+ reports 10.15.7).

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Sync: uaBrowser()

When you don't need accurate version or device detection, a synchronous call is simpler:

import uaBrowser from 'ua-browser'

const { browser, os, device, language } = uaBrowser()

if (device === 'Mobile') {
  // Note: a phone in desktop mode is detected as 'PC' here.
  // Use uaBrowser.detect() when accurate device detection matters.
}

Differences from detect():

Field	uaBrowser() sync	uaBrowser.detect() async
version	Frozen UA value (149.0.0.0)	Real version (149.0.7827.102)
osVersion	Frozen UA value (10.15.7)	Real version (26.5.1)
device	Phone in desktop mode → 'PC'	Phone in desktop mode → 'Mobile'
arch	'unknown' (no Client Hints)	'arm64' / 'x86_64'

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Named Exports (Tree-shakeable)

Import only what you need — unused code is eliminated by tree-shaking:

import {
  parseUA,           // pure function, ideal for SSR / Node.js
  parseHeaders,      // parse UA and Client Hints from HTTP headers
  ACCEPT_CH,         // response header constant to request Client Hints
  getEnvContext,     // collect all browser signals (Client Hints, WebGL, etc.)
  getNavContext,     // read current browser navigator context
  getWindowsVersion, // async: accurately distinguish Windows 10 / 11
  getLanguage,       // extract browser language from NavContext
  isWebview,         // detect Android Webview / iOS WKWebView
  detectBot,         // standalone bot detection
  detectBrowser,     // standalone browser detection
  detectOS,          // standalone OS detection
  detectEngine,      // standalone rendering engine detection
  detectDevice,      // standalone device type detection
  detectArch,        // standalone CPU architecture detection
  detectHeadless,    // standalone headless browser detection
  satisfies,         // condition-matching helper
  VERSION            // current library version
} from 'ua-browser'