User-Agent parser: browser, OS and bots

How it works

The User-Agent is the string every browser or HTTP client uses to introduce itself to a server. It is long and confusing because it carries decades of compatibility baggage: almost every browser claims to be «Mozilla» and many mention «Safari» without being Safari. This parser breaks it down.

Paste a string from your logs, your analytics or the dev tools, or press Use my browser’s to see your own. You get the browser and its version, the rendering engine (Blink, Gecko, WebKit or Trident), the operating system and the device type: desktop, mobile, tablet, TV or console.

It also recognizes bots and automated clients: search and AI crawlers, social media link previews, testing tools and clients such as curl or python-requests. That helps when filtering traffic in logs or figuring out why a site answers a client differently.

Many browsers now send a reduced User-Agent, with the minor version set to 0.0.0 and a frozen OS. The tool points that out so you do not read too much into it. Everything is processed in your browser.

Examples

Safari on iPhone

Input

Mozilla/5.0 (iPhone; CPU iPhone OS 18_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/18.1 Mobile/15E148 Safari/604.1

Output

Browser           Safari 18.1
Engine            WebKit 605.1.15
Operating system  iOS 18.1
Device            Mobile

Google crawler

Input

Mozilla/5.0 (Linux; Android 6.0.1; Nexus 5X Build/MMB29P) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.6778.69 Mobile Safari/537.36 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)

Output

Browser        Chrome 131.0.6778.69
Device         Bot or automated client
Bot or client  Googlebot

Frequently asked questions

Why does Windows 11 show as «10 / 11»?

Browsers send Windows NT 10.0 on both Windows 10 and 11, so the User-Agent cannot tell them apart. To know, request the Sec-CH-UA-Platform-Version header (Client Hints).

Can I trust the User-Agent?

Not entirely: any client can send whatever text it likes, and modern browsers freeze part of the information. Use it for statistics or debugging, not for security decisions.

Which bots does it recognize?

Google, Bing, DuckDuckGo, Apple, Yandex and Baidu crawlers, AI crawlers such as GPTBot, ClaudeBot and PerplexityBot, social network previews, Lighthouse, headless Chrome and clients like curl, Wget, Postman or python-requests.