User-Agent 解析器
粘贴一个 user-agent 字符串，或从你自己的开始。在浏览器中解析：你粘贴的内容不会被发送到任何地方。
user-agent 字符串只是客户端选择发送的内容，很容易修改，而且常常故意含糊，因此请把结果视为声明而非事实。
此内容尚无中文版本。在发布译文之前以英语显示。
Every request a browser makes carries a User-Agent header: a line of text that names the browser, its rendering engine and the operating system it runs on. Websites use it to serve compatible code and to count visitors by platform; this site shows yours on the homepage.
The string is a historical patchwork. Almost every browser still begins with Mozilla/5.0, Chrome claims to be Safari, and Edge claims to be Chrome. The parser reads past that and reports the browser, engine, operating system, device type and CPU architecture the string claims.
Since 2022, Chromium-based browsers send a reduced user-agent: the operating system version and device model are frozen to fixed values, and the real details are only available as User-Agent Client Hints, which a page has to ask for. Where your browser offers them, they are shown next to the parsed result. Everything runs in your browser.
常见问题
Can a website identify me from my user-agent?
Not on its own: millions of people share the same string. Combined with many other browser details it contributes to fingerprinting, which is why browsers now reduce it.
Why does my Windows 11 PC show Windows 10?
Reduced user-agent strings report "Windows NT 10.0" for both. The platform-version client hint tells them apart; it is shown when your browser supports it.
Is a bot always honest about being a bot?
No. Well-behaved crawlers such as Googlebot identify themselves, but anyone can send any user-agent. Verify crawlers by reverse DNS, not by the string.