User-Agent inspector
Decode the string behind a request before you misclassify a browser, bot, device, or rendering engine.
User-agent reference
How a user-agent string is structured
Most user-agent strings combine compatibility tokens, platform details, rendering engine information, and browser brand/version data. The format is historical and often messy, so treat the result as a clue rather than a source of truth.
Example: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36
Common crawler user agents
| Crawler | User-agent signature |
|---|---|
| Googlebot | Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html) |
| Baiduspider | Mozilla/5.0 (compatible; Baiduspider/2.0; +http://www.baidu.com/search/spider.html) |
| Bingbot | Mozilla/5.0 (compatible; bingbot/2.0; +http://www.bing.com/bingbot.htm) |
Frequently asked questions
What is a user agent?
A user-agent string is sent by the browser, crawler, or client with a request. It can help identify browser family, operating system, device class, rendering engine, and sometimes whether the request came from an automated bot.
How can I change my user agent?
Most modern browsers let you override the user agent in developer tools. In Chrome, open DevTools, open More tools, choose Network conditions, disable the default browser user agent, and pick another value.
Can user-agent strings be trusted?
Not completely. Browsers, bots, proxies, privacy tools, and test clients can spoof or reduce user-agent details. Use feature detection and server-side signals when correctness matters.
Why do modern browsers expose less user-agent detail?
Reducing user-agent detail helps limit passive fingerprinting. Some browser information is moving toward Client Hints, where the browser can disclose specific fields in a more controlled way.