User-Agent Parser
Parse and analyze User-Agent strings to extract detailed information about browsers, operating systems, devices, and engines. Perfect for web analytics and debugging.
Input
Sample User-Agents:
Parsed Information
No data parsed yet
Enter a user-agent string and click "Parse User-Agent"
About User-Agent Parsing
User-Agent strings contain information about the browser, operating system, and device. This tool parses these strings to extract structured data useful for web analytics, feature detection, and debugging. Note that User-Agent strings can be spoofed and should not be relied upon for security purposes.
About User-Agent Parser
An advanced User-Agent string parser that extracts detailed information about browsers, operating systems, devices, and rendering engines from HTTP User-Agent headers. This tool decodes complex User-Agent strings into readable, structured data for analysis and debugging purposes.
Why use a User-Agent Parser?
User-Agent strings contain valuable information about visitors' browsers and devices, but they're often cryptic and difficult to interpret manually. This parser saves time by automatically extracting and organizing this data, making it easier to understand traffic patterns, debug browser-specific issues, and optimize user experiences across different platforms.
Who is it for?
Essential for web developers debugging browser compatibility issues, data analysts studying user demographics, QA testers validating cross-platform functionality, and digital marketers understanding their audience's technical preferences. Perfect for anyone working with web analytics or browser detection.
How to use the tool
Paste a User-Agent string into the input field (from browser dev tools or server logs)
The tool automatically parses and displays browser name, version, and engine information
Review the extracted operating system, device type, and platform details
Analyze the rendering engine and version for compatibility testing
Use the parsed data for analytics, debugging, or user experience optimization
Frequently Asked Questions
How do I parse a User-Agent string?
Paste a User-Agent string (the one your browser sends, or one captured from server logs) and the tool decomposes it into: browser name + version, OS name + version, device type (desktop/mobile/tablet), engine (Blink/WebKit/Gecko), and architecture. Useful for: log analysis, debugging user-reported bugs ('what browser were they on?'), feature-detection sanity-checking. Runs entirely in your browser via the ua-parser-js library — no server roundtrip, your UA strings never leave the device.
What is a User-Agent string?
The User-Agent header is sent by browsers and HTTP clients identifying themselves. Format is a tradition-laden mess — modern browsers send strings like `Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36` — a layered history of 'we're compatible with...' claims. Parsing extracts the actual browser + OS. Used by servers for: analytics, feature gating (some older browsers need polyfills), responsive design serving, and bot detection.
Is the parsing done on a server?
No — User-Agent parsing runs entirely in your browser via the ua-parser-js library (or similar). The parsing logic is regex-based pattern matching against the string; no server lookup needed. Zero HTTP requests during parsing (verifiable in DevTools' Network tab). Safe for sensitive UA strings (custom corporate browser builds, security-research UAs).
Why is User-Agent being deprecated?
The UA string has problems. (1) **Privacy**: high entropy (combinations of browser + OS + version create near-unique fingerprints). (2) **Reliability**: easily spoofed (anyone can send any UA). (3) **Compatibility tax**: browsers send misleading legacy strings to avoid being misidentified by old user-agent-sniffing code. Chrome (and other Chromium browsers) is **freezing** the UA string and migrating to **User-Agent Client Hints** — a structured, reduced-entropy replacement (`Sec-CH-UA: ...`, `Sec-CH-UA-Mobile: ?0`, `Sec-CH-UA-Platform: 'Linux'`). Servers opt in to receiving specific hints via the `Accept-CH` header.
Can I trust the User-Agent for security decisions?
**No — UA is trivially spoofable.** Anyone can send any UA string (browser extensions, curl with `-A`, custom HTTP clients). Don't use UA for: authentication, authorization, blocking 'unsupported' browsers in security-sensitive contexts. Do use UA for: analytics (knowing what your users use), feature detection fallback (combined with capability detection), responsive design hints (with media queries as the primary mechanism). For 'this user must be on a real browser' guarantees, use real signals (CAPTCHA, behavioral analysis), not UA.
How accurate is browser/OS detection?
Very accurate for mainstream browsers (Chrome, Firefox, Safari, Edge) and OSes (Windows 10+, macOS, Linux distros, iOS, Android). Less accurate for: niche browsers (some claim to be Chrome for compatibility), embedded WebViews (often masquerade as Chrome/Safari), and bot/crawler UAs (highly variable). Modern phones underreport iOS/Android version for privacy. The library used is well-maintained — most major browsers are parsed correctly. Edge cases: enterprise corporate browsers with custom UAs, headless browsers (Puppeteer, Playwright), in-app webviews.
What are Client Hints?
**User-Agent Client Hints** (RFC 8942) are the modern replacement for UA sniffing. Instead of one big string with everything, the client sends discrete hints — only what the server asks for. Headers: `Sec-CH-UA` (browser brand list), `Sec-CH-UA-Platform`, `Sec-CH-UA-Mobile`, `Sec-CH-UA-Arch`, `Sec-CH-UA-Bitness`, `Sec-CH-UA-Model` (etc., for higher-entropy hints requiring explicit opt-in via `Accept-CH`). Privacy benefit: low-entropy by default (just browser brand + mobile/desktop); high-entropy on request only. JavaScript API: `navigator.userAgentData.getHighEntropyValues(['model', 'platformVersion'])`. Supported in Chromium-based browsers since 2020; Safari, Firefox slower to adopt.
When should I use UA parsing vs feature detection?
**Feature detection** is preferred for most cases. Check if a feature exists (`if (window.IntersectionObserver) { ... }`) instead of inferring it from the browser. UA-based logic is brittle — new browser versions break it. **UA parsing** is useful for: analytics (long-term reporting on browser/OS distribution), bug triage ('this only happens on Safari 14.x'), workarounds for known browser-specific bugs that can't be feature-detected. For shipping features, use feature detection + progressive enhancement. For understanding your audience, parse UAs from logs.
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