HTTP header File User-agent detailed

What is User-agent

User-agent Chinese name is the user agent, called UA, it is a special string header, so that the server can identify the operating system and version of the client, CPU type, browser and version, browser rendering engine, browser language, browser plug-ins and so on. Some websites often judge the UA to send different pages to different operating systems, different browsers, which may cause some pages to not display properly in a browser, but can bypass detection by disguising the UA.

The UA string of the browser

The standard format is: Browser identification (operating system identity; encryption level identification; browser language) The rendering engine identifies version information (but different browser formats are different and broadly include them)

Browser identity

Since many websites ignore the two-digit version number when they are doing UA detection, it may cause the browser and later versions to receive bad pages, so the browser identifier is pinned to the browser from the version after browser 10, and the actual version information is added at the end of the UA string.

Operating System identity

Freebsd

X11; FreeBSD (version No.) I386 X11; FreeBSD (Version No.) AMD64

Linux

X11; Linux PPC X11; Linux PPC64 X11; Linux i686 X11; Linux x86_64

Mac

Macintosh; PPC Mac OS X Macintosh; Intel Mac OS X

Solaris

X11; SunOS i86pc X11; SunOS sun4u

Windows:

Windows NT 6.1 corresponding operating system Windows 7 Windows NT 6.0 corresponding operating system Windows Vista Windows NT 5.2 corresponding operating system Windows 2003 Windows NT 5.1 pair Should the operating system Windows XP Windows NT 5.0 corresponds to the operating system Windows Windows ME Windows 98

Encryption level identification

N: Indicates no security encryption I: Indicates weak secure encryption U: indicates strong secure encryption