Browser
CPU
Device
Browser Engine
Operating System
User Agent Syntax
The syntax of a user agent string is:
User-Agent: <product> / <product-version> <comment>
The common format for a browser user agent string is:
User-Agent: Mozilla/5.0 (<system-information>) <platform> (<platform-details>) <extensions>
For example, the user agent string for Firefox is:
Mozilla/5.0 (platform; rv:geckoversion) Gecko/geckotrail Firefox/firefoxversion
Mozilla/5.0
is the token for the browser
platform
is the platform that the browser is running on (e.g. Windows, Max, Linux, etc.)
rv:geckoversion
is the version of the Gecko browser engine.
Gecko/geckotrail
means the browser is based on the Gecko browser engine.
Firefox/firefoxversion
is the Firefox version number.