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User Agent Parser

Parse a User-Agent string into browser, engine, operating system, device and CPU, and spot crawlers, AI bots and HTTP clients.

Runs locally, never uploaded

User-Agent string

0 chars · 0 B

Result

Result appears here

What this tool does

The User Agent Parser reads the User-Agent header that browsers, apps and bots send with every HTTP request, and turns it into plain facts: the browser and its version, the rendering engine, the operating system, the device type (desktop, phone, tablet, TV, console…), the device vendor and model when the string names them, and the CPU architecture.

It also tells you when the string does not belong to a person at all. Search engine crawlers, AI training crawlers and AI assistants fetching pages, link-preview bots from chat and social apps, SEO tools, uptime monitors and command-line HTTP clients are recognized and labelled, which helps when reading server logs or deciding what to put in robots.txt.

How to use it

  1. Open the page: your own User-Agent is already parsed.
  2. Paste any other User-Agent string, for example a line from an access log. A leading User-Agent: header name is removed automatically.
  3. Read the result table and copy any value with its button. Press Sample to see a mobile Safari string, or My browser to return to yours.

Example

Mozilla/5.0 (iPhone; CPU iPhone OS 17_5 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.5 Mobile/15E148 Safari/604.1

This string is Mobile Safari 17.5 on iOS 17.5, using the WebKit engine, on an Apple iPhone. A string such as Mozilla/5.0 (compatible; GPTBot/1.2; +https://openai.com/gptbot) is reported as GPTBot 1.2, an AI crawler.

Tips

  • Do not rely on the User-Agent for security decisions; anyone can send any string. Verify important crawlers with a reverse DNS lookup.
  • For feature support, test the feature in JavaScript instead of sniffing the browser version.
  • Headless Chrome and automation tools are flagged separately, which is useful when you investigate scraping.

FAQ

› What is my user agent?

When you open this page, the input is filled with your own browser's User-Agent string and parsed right away. Press My browser to bring it back after trying other strings.

› How accurate is User-Agent parsing?

It is good for browser, engine and operating system families, but a User-Agent can be changed by the user, extensions or privacy settings. Modern Chrome also freezes parts of the string (for example Windows 11 still reports Windows NT 10.0), so treat device and version details as hints.

› Which bots does it recognize?

Search engine crawlers (Googlebot, Bingbot, Baiduspider, YandexBot…), AI crawlers and agents (GPTBot, ChatGPT-User, ClaudeBot, PerplexityBot, CCBot…), social link-preview fetchers, SEO crawlers, uptime monitors and common HTTP clients such as curl, python-requests and Postman. Other strings containing bot, crawler or spider are flagged as other bots.

› Is the User-Agent sent anywhere?

No. Parsing runs entirely in your browser with the open-source ua-parser-js library and a built-in bot list.