Latest Firefox 31 user agents:

User Agent Platform Device
Mozilla/5.0 (X11; Ubuntu; Linux x8664; rv:31.0) Gecko/20100101 Firefox/31.0 Ubuntu Unknown
Mozilla/5.0 (X11; Ubuntu; Linux i686; rv:31.0) Gecko/20100101 Firefox/31.0,gzip(gfe) Ubuntu Unknown
Mozilla/5.0 (X11; Ubuntu; Linux armv7l; rv:31.0) Gecko/20100101 Firefox/31.0 Ubuntu Unknown
Mozilla/5.0 (X11; SunOS i86pc; rv:31.0) Gecko/20100101 Firefox/31.0 Solaris Unknown
Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Firefox/31.0 GNU/Linux Unknown
Mozilla/5.0 (X11; Linux x8664; rv:31.0) Gecko/20100101 Firefox/31.0 GNU/Linux Unknown
Mozilla/5.0 (X11; Linux i686; rv:31.0) Gecko/20100101 Firefox/31.0 SCREENRES/1024x768 PLC/PLC_3_3_0_LR5 HW/Zotac_AD04 PLCMODE/FOOTWALL GNU/Linux Unknown
Mozilla/5.0 (X11; Linux i686 on x86_64; rv:31.0) Gecko/20100101 Firefox/31.0 GNU/Linux Unknown
Mozilla/5.0 (X11; Linux i686 on x8664; rv:31.0) Gecko/20100101 Firefox/31.0 GNU/Linux Unknown
Mozilla/5.0 (X11; Linux i586; rv:31.0) Gecko/20100101 Firefox/31.0) GNU/Linux Unknown
Mozilla/5.0 (X11; FreeBSD amd64; rv:31.0) Gecko/20100101 Firefox/31.0 FreeBSD Unknown
Mozilla/5.0 (Windows NT 8.1; Win64; rv:31.0) Gecko/20100101 Firefox/31.0 Windows NT Unknown
Mozilla/5.0 (Windows NT 6.3; x64; rv:31.0) Gecko/20100101 Firefox/31.0 Windows 8 Unknown
Mozilla/5.0 (Windows NT 6.3; x64; rv:31.0) Gecko/20100101 Firefox/31 Windows 8 Unknown
Mozilla/5.0 (Windows NT 6.3; WOW64; rv:31.0; Neustar WPM) Gecko/20100101 Firefox/31.0 Windows 8 Unknown
Mozilla/5.0 (Windows NT 6.3; Win64; x64; rv:31.0) Gecko/20100101 Firefox/31.0 Windows 8 Unknown
Mozilla/5.0 (Windows NT 6.3; rv:31.0) Gecko/20100101 Firefox/31.0 AlexaToolbar/psai366f-2.1 Windows 8 Unknown
Mozilla/5.0 (Windows NT 6.3; rv:31.0) Gecko/20100101 Firefox/31.0 Windows 8 Unknown
Mozilla/5.0 (Windows NT 6.3; de; rv:31.0) Gecko/20100101 Firefox/31.0 Windows 8 Unknown
Mozilla/5.0 (Windows NT 6.2; WOW64; rv:31.0) Gecko/20100101 Firefox/31.0 K-Meleon/75.0 Windows 8 Unknown