User Agent Parser

Paste any User-Agent string and get a structured breakdown: browser name and version, operating system and version, device type (desktop / mobile / tablet / bot), and the rendering engine. Handles modern Chrome / Safari / Firefox / Edge UAs plus mobile Chrome / Safari, and detects bots (Googlebot, Bingbot, GPTBot, etc.).

How to use the User Agent Parser

Paste a UA string (from your server logs, an analytics event, or any header capture). The parser breaks it down. Use my browser’s UA auto-fills with the UA your current session is sending — useful for sanity-checking what the world sees from you.

About User Agent Parser

The User-Agent header is browsers’ (very) approximate self-identification. It started as a one-line free-form string in early Mozilla and has grown into a baroque pseudo-syntax that includes the names of every browser the current browser ever wanted to be compatible with (“Mozilla/5.0 (...) AppleWebKit/... (KHTML, like Gecko) Chrome/... Safari/...”). Modern browsers are slowly transitioning to the User-Agent Client Hints API (sec-ch-ua-* headers) for structured data, but UA parsing remains essential for log analysis, server-side rendering decisions, and analytics tools that need to work with older clients.

This parser identifies the dominant signals in a UA: which browser is actually rendering the page (the last token in the long compatibility chain), which OS the user is on, and whether the request is from a bot (search engines, AI scrapers, monitoring services). It’s purposefully simpler than libraries like ua-parser-js: covers the common cases without dragging in a huge regex table.

Common use cases

  • Log analysis — break down traffic by browser / OS for capacity planning.
  • Bot detection — confirm whether a suspicious UA is a known bot.
  • Server-side rendering decisions — different defaults for mobile vs desktop.
  • Debugging cross-browser issues — confirm what browser version reported a bug.

Frequently asked questions

Why does my Edge browser report Chrome?
Edge uses the Chromium engine and includes "Chrome/" in its UA for compatibility. The parser picks the latest browser identifier in the chain, which is "Edg/" \xE2\x80\x94 if both are present, Edge wins.

How accurate is bot detection?
For well-known bots (Googlebot, Bingbot, GPTBot, ClaudeBot, CCBot, Slackbot, Discordbot) it's authoritative. Hostile bots that fake a browser UA can't be caught by string parsing alone \xE2\x80\x94 use rate-based heuristics.

What about Client Hints?
This tool parses the legacy UA string. For Client Hints (sec-ch-ua-*), use the structured headers directly \xE2\x80\x94 they don't need parsing.