UA-Parser is a multi-language library that parses User Agent strings to extract information about the browser, operating system, and device. It provides a unified way to parse and analyze User Agent data across various programming languages, making it useful for web analytics, device detection, and browser compatibility checks.

Pros

• Multi-language support (JavaScript, PHP, Python, Java, and more)
• Regular updates to keep up with new browser and device releases
• Extensive test suite for accuracy and reliability
• Community-driven project with active maintenance

Cons

• Parsing accuracy may vary for less common or newer User Agents
• Performance can be a concern for high-volume processing
• Requires periodic updates to maintain accuracy as new devices and browsers emerge
• Limited information extraction compared to some commercial alternatives

Code Examples

1. JavaScript example (using Node.js):

const uaParser = require('ua-parser-js');

const ua = 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.124 Safari/537.36';
const result = uaParser(ua);

console.log(result.browser);  // { name: 'Chrome', version: '91.0.4472.124' }
console.log(result.os);       // { name: 'Windows', version: '10' }
console.log(result.device);   // { vendor: undefined, model: undefined, type: undefined }

2. Python example:

from ua_parser import user_agent_parser

ua_string = 'Mozilla/5.0 (iPhone; CPU iPhone OS 14_6 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/14.1.1 Mobile/15E148 Safari/604.1'
parsed_string = user_agent_parser.Parse(ua_string)

print(parsed_string['user_agent'])  # {'family': 'Mobile Safari', 'major': '14', 'minor': '1', 'patch': '1'}
print(parsed_string['os'])          # {'family': 'iOS', 'major': '14', 'minor': '6', 'patch': None, 'patch_minor': None}
print(parsed_string['device'])      # {'family': 'iPhone', 'brand': 'Apple', 'model': 'iPhone'}

3. PHP example:

<?php
require_once 'vendor/autoload.php';
use UAParser\Parser;

$ua = 'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.114 Safari/537.36';
$parser = Parser::create();
$result = $parser->parse($ua);

echo $result->ua->family;    // "Chrome"
echo $result->os->toString(); // "Linux"
echo $result->device->family; // "Other"
?>

Getting Started

To use UA-Parser in your project, follow these steps:

1. Install the library for your preferred language:

   • JavaScript: npm install ua-parser-js
   • Python: pip install ua-parser
   • PHP: composer require ua-parser/uap-php

2. Import the library in your code (see examples above).

3. Parse User Agent strings using the provided functions or methods.

4. Access the parsed information (browser, OS, device) from the returned object.

Refer to the language-specific documentation in the GitHub repository for more detailed usage instructions and advanced features.