ua-parser-lite

A lightweight, pure TypeScript utility to parse browser User-Agent strings and detect browser, operating system, CPU, device, and engine information.

Features

• Detect browser name and version
• Detect operating system name and version
• Detect CPU architecture
• Detect device type (mobile, tablet, desktop, smart TV, console, wearable)
• Detect rendering engine name and version
• Works in Node.js and browser environments
• Pure TypeScript, no external dependencies

Installation

pnpm add ua-parser-lite
# or
npm install ua-parser-lite
yarn add ua-parser-lite

Usage

Parse default User-Agent (browser environment)

import { parseUserAgent } from "ua-parser-lite";

const info = parseUserAgent();
console.log(info);

Parse a custom User-Agent string

const ua = "Mozilla/5.0 (iPhone; CPU iPhone OS 17_1 like Mac OS X) Version/17.0 Mobile/15E148 Safari/604.1";
const info = parseUserAgent(ua);

console.log(info.browser.name);       // Safari
console.log(info.browser.version);    // 17.0
console.log(info.os.name);            // iOS (iPhone)
console.log(info.os.version);         // 17.1
console.log(info.device.type);        // mobile
console.log(info.cpu.architecture);   // undefined
console.log(info.engine.name);        // WebKit

API

parseUserAgent(userAgent?: string): UserAgentInfo

| Property | Type | Description | |----------|------|-------------| | userAgent | string | Original User-Agent string | | browser | { name: string; version: string } | Browser name and version | | os | { name: string; version: string } | Operating system name and version | | cpu | { architecture?: string } | CPU architecture (if detected) | | device | { type?: string } | Device type: mobile, tablet, desktop, smarttv, console, wearable, unknown | | engine | { name: string; version: string } | Rendering engine name and version |

Example Output

{
  userAgent: "Mozilla/5.0 (iPhone; CPU iPhone OS 17_1 like Mac OS X)...",
  browser: { name: "Safari", version: "17.0" },
  os: { name: "iOS (iPhone)", version: "17.1" },
  cpu: { architecture: undefined },
  device: { type: "mobile" },
  engine: { name: "WebKit", version: "605.1.15" }
}

Testing

We use Jest for unit testing.

pnpm test           # Run all tests
pnpm test:coverage  # Run tests with coverage and open HTML report

Contributing

1. Fork the repository
2. Install dependencies: pnpm install
3. Run tests: pnpm test
4. Generate coverage report: pnpm test:coverage

License

MIT