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UA Parser

Parse any User-Agent string to detect browser, rendering engine, OS, device type and CPU architecture. One click fills in your own browser's UA.

Samples:
Parsed result
Browser
Unknown
Engine
Unknown
Operating system
Unknown
Device type
Unknown
CPU / Arch
Unknown

How to use

Purpose

Online User-Agent parser. Decodes UA strings into readable structure: browser name and version, OS and version, device type (desktop / mobile / tablet / bot), rendering engine (Blink / Gecko / WebKit), CPU architecture. Provides UA templates for common browsers (Chrome / Firefox / Safari / Edge / IE / WeChat / Baiduspider) and a "fake UA generator". Common for server log analysis, traffic statistics, bot detection, cross-browser debugging. All parsing runs locally.

Steps

  1. Paste a User-Agent string (from logs or navigator.userAgent)
  2. Right pane: browser / version / OS / device / engine
  3. Device class: Desktop / Mobile / Tablet / Bot
  4. Bot detection: Googlebot / Baiduspider / Bingbot / facebookexternalhit / WhatsApp Preview
  5. Common UA templates: one-click insert Chrome mobile / Safari iPhone / WeChat
  6. Fake UA generator: combine OS + browser + version to a custom UA
  7. Current browser UA: read navigator.userAgent
  8. Batch: one UA per line

FAQ

Why are Chrome UAs so long, with Mozilla / Safari / KHTML?
Historical baggage. Early websites only served modern features to "Mozilla" UAs (IE without "Mozilla" was excluded), so browsers added "Mozilla/5.0" to fool sniffing. Chrome wanted Safari WebKit rendering, so added "Safari/x"; wanted broader compatibility, so added "KHTML". Every browser UA is a nesting doll. Microsoft Edge UA contains Chrome / Safari / KHTML / Mozilla simultaneously.
What is UA Client Hints? Will it replace User-Agent?
Google-driven new standard: separate HTTP headers Sec-CH-UA / Sec-CH-UA-Mobile / Sec-CH-UA-Platform replace string parsing. Benefits: no regex parsing on the server; better privacy (default low-entropy fields). Status: Chrome supports it; Firefox / Safari partial. Transition: User-Agent strings will stick around for a long time — new code can use Client Hints with UA string fallback.
Can I bypass anti-scraping by faking UA?
UA alone is probably not enough. Anti-scraping typically uses: 1) UA (basic check); 2) behavior fingerprints (mouse trajectories, intervals); 3) IP (proxy detection); 4) Canvas fingerprint; 5) WebGL; 6) fonts; 7) timezone vs IP geolocation match. Single-point UA fakery passes only the most basic. Advanced: puppeteer / playwright + stealth plugin + proxy pool.
How to detect search engine crawlers?
UA features: Googlebot / Baiduspider / Bingbot / Sogou / YandexBot / DuckDuckBot. Authenticity verification: reverse DNS to confirm IP belongs to google.com / baidu.com subdomain (defends against fake UAs). This tool detects by UA only; in production, add reverse DNS verification.
How to detect WeChat in-app browser?
WeChat in-app UA contains MicroMessenger/Version. Example: Mozilla/5.0 (iPhone; CPU iPhone OS 15_0) ... MicroMessenger/8.0.20 ... Use cases: 1) show share buttons in WeChat ecosystem (hidden in normal browsers); 2) certain JSAPIs cannot be called outside WeChat — warn user; 3) WeChat mini-program webview UA also contains miniProgram.

Use cases

  • Server log analysis: parse UA distribution
  • Traffic stats: mobile vs desktop, browser market share
  • Bot detection: identify search engines and malicious crawlers from logs
  • Cross-browser debug: copy target browser UA for development testing
  • A/B testing: serve different versions by browser type

Use cases

Server log analysis, traffic stats, bot detection, cross-browser debug, A/B testing. Backend, SEO, ops, QA. Detailed field parsing, bot detection, UA templates, batch processing are the differentiators.