User Agent String explained :
 Firefox 21.0 | |
|---|---|
| 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 |
| Windows NT 6.2 | Operating System:  Windows 8 |
| rv:21.0 | CVS Branch Tag The version of Gecko being used in the browser |
| Gecko | Gecko engine inside |
| 20130326 | Build Date: the date the browser was built |
| Firefox | Name : Firefox |
| 21.0 | Firefox version |
| First visit: | 2013.04.01 10:33 |
| Last visit: | 2025.10.09 12:57 |
All Firefox user agent strings | |