User Agent String explained :
 Firefox 3.1 | |
|---|---|
| Mozilla | MozillaProductSlice. Claims to be a Mozilla based user agent, which is only true for Gecko browsers like Firefox and Netscape. For all other user agents it means 'Mozilla-compatible'. In modern browsers, this is only used for historical reasons. It has no real meaning anymore |
| 5.0 | Mozilla version |
| X11 | X Window System a windowing system for bitmap displays |
| U | Security values:
|
| Linux x86_64 | Operating System:  Linuxrunning on a Intel CPU running on a 64 bit processor |
| en-US | Language Tag, indicates the language for which the client had been localized (e.g. menus and buttons in the user interface) en-US =  English - United States |
| rv:1.9.1b3 | CVS Branch Tag The version of Gecko being used in the browser |
| Gecko | Gecko engine inside |
| 20090327 | Build Date: the date the browser was built |
| GNU | Operating System:  GNU |
| Linux | Operating System: Linux |
| x86_64 | Using a 64 bit processor |
| Firefox | Name : Firefox |
| 3.1 | Firefox version |
| First visit: | 2009.04.04 08:20 |
| Last visit: | 2019.04.13 01:29 |
All Firefox user agent strings | |