For more information, please visit the following pages:

• Firefox
• Mozilla Foundation
• Gecko

Latest user agents (if you are looking for complete list, download it here):

• Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_2; rv:51.0) Gecko/20100101 Firefox/51.0
• Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_1; rv:51.0.1) Gecko/20100101 Firefox/51.0.1
• Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:51.0) Gecko/20100101 Firefox/51.0 [ip:151.90.4.193]
• Mozilla/5.0 (Android 8.1.0; Tablet; rv:51.0) Gecko/51.0 Firefox/51.0
• Mozilla/5.0 (Windows NT 6.1; rv:47.0) Gecko/20100101 Firefox/51.0
• Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:83.0) Gecko/20100101 Firefox/51.0
• Mozilla/5.0 (Macintosh; Intel Mac OS X 10_9_5) Gecko/20100101 Firefox/51.0
• Mozilla/5.0 (X11; U; Linux ppc64; en-US; rv:1.8.1.14) Gecko/20080418 Ubuntu/7.10 (gutsy) Firefox/51.0
• Mozilla/5.0 (Android 4.0.3; Mobile; rv:51.0) Gecko/51.0 Firefox/51.0
• Mozilla/5.0 (X11; U; Linux x86_64; zh-TW; rv:1.8.1.11) Gecko/20071204 Ubuntu/7.10 (gutsy) Firefox/51.0
• Mozilla/5.0 (X11; U; Linux i686; es-ES; rv:1.8.1.12) Gecko/20080213 Firefox/51.0
• Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.9.1b3) Gecko/20090405 Firefox/51.0.1
• Mozilla/5.0 (X11; U; SunOS sun4u; de-DE; rv:1.8.1.6) Gecko/20070805 Firefox/51.0
• Mozilla/5.0 (X11; Linux i686 on x86_64; rv:51.0) Gecko/20100101 Firefox/51.0,gzip(gfe)
• Mozilla/5.0 (Windows; U; Windows NT 5.1; en; rv:1.7.10) Gecko/20050716 Firefox/51.0
• Mozilla/5.0 (X11; U; Linux i686; pt-BR; rv:1.9.0.2) Gecko/2008092313 Ubuntu/8.04 (hardy) Firefox/51.0.1
• Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9b3pre) Gecko/2008020507 Firefox/51.0
• Mozilla/5.0 (Android 4.4.2; Tablet; rv:51.0.2) Gecko/51.0.2 Firefox/51.0.2
• Mozilla/5.0 (Windows NT 10.0; Win64; rv:51.0) Gecko/20100101 Firefox/51.0
• Mozilla/5.0 (Windows NT 10.0; WOW64; rv:51.0; .NET CLR 4.0.30319; ffco7) Gecko/20100101 Firefox/51.0
• Mozilla/5.0 (Windows NT 6.2; rv:51) Gecko/20100101 Firefox/51.0
• Mozilla/5.0 (X11; U; Linux i686; sv-SE; rv:1.8.1.2) Gecko/20061023 SUSE/2.0.0.2-1.1 Firefox/51.0.1
• Mozilla/5.0 (Windows; U; Windows NT 5.1; ja; rv:1.9.2a1pre) Gecko/20090402 Firefox/51.0.1
• Mozilla/5.0 (Windows; U; Windows NT 5.1; rv:1.7.3) Gecko/20041001 Firefox/51.0.1
• Mozilla/5.0 (Windows NT 5.1; rv:51.0; .NET CLR 4.0.30319; ffco7) Gecko/20100101 Firefox/51.0
• Mozilla/5.0 (Macintosh; Intel Mac OS X 11_5_6; rv:51.0) Gecko/20100101 Firefox/51.0
• Mozilla/5.0 (Macintosh; U; PPC Mac OS X Mach-O; en-US; rv:1.7.9) Gecko/20050711 Firefox/51.0
• Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8.1.19) Gecko/20081230 Firefox/51.0
• Mozilla/5.0 (X11; U; NetBSD alpha; en-US; rv:1.8.1.6) Gecko/20080115 Firefox/51.0
• Mozilla/5.0 (Macintosh; Intel Mac OS X 6_4_6; rv:51.0) Gecko/20100101 Firefox/51.0
• Mozilla/5.0 (Macintosh; U; PPC Mac OS X Mach-O; en-US; rv:1.8.1.4) Gecko/20070515 Firefox/51.0
• Mozilla/5.0 (X11; U; Linux i686; de; rv:1.9.0.12) Gecko/2009070812 Ubuntu/8.04 (hardy) Firefox/51.0.1
• Mozilla/5.0 (Windows; U; Windows NT 6.0; de; rv:1.9.1.2) Gecko/20090729 Firefox/51.0.1
• Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.6) Gecko/20100117 Gentoo Firefox/51.0
• Mozilla/5.0 (X11; U; Linux i686; pl-PL; rv:1.7.12) Gecko/20051010 Firefox/51.0
• Mozilla/5.0 (Android 4.0.4; Tablet; rv:51.0) Gecko/51.0 Firefox/51.0
• Mozilla/5.0 (Windows NT 10.0; WOW64; rv:51.0) Gecko/20100101 Firefox/51.0|20170125094131
• Mozilla/5.0 (X11; U; Linux x86_64; zh-TW; rv:1.9.0.13) Gecko/2009080315 Ubuntu/9.04 (jaunty) Firefox/51.0
• Mozilla/5.0 (Windows NT 6.3; WOW64; rv:43.0) Gecko/20100101 Firefox/51.0
• Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.0.7) Gecko/2009030516 Ubuntu/9.04 (jaunty) Firefox/51.0
• Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.8.1.3) Gecko/20070322 Firefox/51.0
• Mozilla/5.0 (X11; U; Linux i686; es-AR; rv:1.8.0.7) Gecko/20060909 Firefox/51.0
• Mozilla/5.0 (Windows NT 6.3; Win64; x64; rv:51.0.3) Gecko/20100101 Firefox/51.0.3
• Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:51.0.1) Gecko/20100101 Firefox/51.0.1
• Mozilla/5.0 (Windows NT 6.2; Win64; x64; rv:51.0.2) Gecko/20100101 Firefox/51.0.2
• Mozilla/5.0 (Windows NT 10.0; rv:51.0.1) Gecko/20100101 Firefox/51.0.1
• Mozilla/5.0 (Windows NT 6.0; rv:51.0.1) Gecko/20100101 Firefox/51.0.1
• Mozilla/5.0 (Windows NT 6.0; Win64; x64; rv:51.0.1) Gecko/20100101 Firefox/51.0.1
• Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.6) Gecko/20050317 Firefox/51.0.1
• Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:51.0.2) Gecko/20100101 Firefox/51.0.2
• Mozilla/5.0 (Windows NT 6.0; Win64; x64; rv:51.0.2) Gecko/20100101 Firefox/51.0.2
• Mozilla/5.0 (X11; U; Linux x86_64; es-ES; rv:1.9.0.12) Gecko/2009070811 Ubuntu/9.04 (jaunty) Firefox/51.0
• Mozilla/5.0 (Windows NT 6.0; Win64; x64; rv:51.0.3) Gecko/20100101 Firefox/51.0.3
• Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9b2) Gecko/2007121016 Firefox/51.0.1
• Mozilla/5.0 (Windows; U; Windows NT 6.0; nl; rv:1.9.0.12) Gecko/2009070611 Firefox/51.0.1
• Mozilla/5.0 (Android 7.0; Tablet; rv:51.0.3) Gecko/51.0.3 Firefox/51.0.3
• Mozilla/5.0 (X11; U; Linux i686; fr-FR; rv:1.9.2.10) Gecko/20100914 Firefox/51.0
• Mozilla/5.0 (Windows NT 5.2; U; de; rv:1.8.0) Gecko/20060728 Firefox/51.0.1
• Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.0.2) Gecko/2008092313 Ubuntu/8.04 (hardy) Firefox/51.0
• Mozilla/5.0 (Windows NT 6.3; rv:51.0.3) Gecko/20100101 Firefox/51.0.3
• Mozilla/5.0 (Windows NT 10.0; WOW64; rv:51.0.2) Gecko/20100101 Firefox/51.0.2
• Mozilla/5.0 (X11; U; Linux i686 (x86_64); en-US; rv:1.9a1) Gecko/20060127 Firefox/51.0.1
• Mozilla/5.0 (Windows NT 6.2; Win64; x64; rv:51.0.1) Gecko/20100101 Firefox/51.0.1
• Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8.1.1) Gecko/20061205 Firefox/51.0
• Mozilla/5.0 (X11; U; Linux x86-64; en-US; rv:1.8.1) Gecko/20061010 Firefox/51.0
• Mozilla/5.0 (Windows NT 6.2; rv:51.0.3) Gecko/20100101 Firefox/51.0.3
• Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.6) Gecko/20050225 Firefox/51.0.1
• Mozilla/5.0 (Windows NT 6.3; rv:51.0.1) Gecko/20100101 Firefox/51.0.1
• Mozilla/5.0 (Windows NT 10.0; rv:51.0) Gecko/20100101 Firefox/51.0 anonymized by Abelssoft 708832980
• Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8.0.12) Gecko/20070530 Fedora/1.5.0.12-1.fc6 Firefox/51.0.1
• Mozilla/5.0 (Windows; U; Windows NT 6.0; de; rv:1.9.0.13) Gecko/2009073022 Firefox/51.0
• Mozilla/5.0 (Windows NT 6.1; rv:51.0.3) Gecko/20100101 Firefox/51.0.3
• Mozilla/5.0 (Windows NT 6.3; Win64; x64; rv:51.0.1) Gecko/20100101 Firefox/51.0.1
• Mozilla/5.0 (Windows NT 6.2; rv:51.0.2) Gecko/20100101 Firefox/51.0.2
• Mozilla/5.0 (Windows NT 6.1; WOW64; rv:51.0.3) Gecko/20100101 Firefox/51.0.3
• Mozilla/5.0 (Windows NT 6.2; Win64; x64; rv:51.0.3) Gecko/20100101 Firefox/51.0.3
• Mozilla/5.0 (Windows NT 10.0; rv:51.0.3) Gecko/20100101 Firefox/51.0.3
• Mozilla/5.0 (Windows NT 5.1; U; zh-cn; rv:1.8.1) Gecko/20091102 Firefox/51.0.1
• Mozilla/5.0 (Windows NT 6.3; rv:51.0.2) Gecko/20100101 Firefox/51.0.2
• Mozilla/5.0 (Windows NT 6.1; WOW64) Gecko/20100101 Firefox/51.0.2
• Mozilla/5.0 (Windows NT 10.0; Win64; x64) Gecko/ Firefox/51.0.2
• Mozilla/5.0 (X11; U; Linux i686; pl; rv:1.8.1b1) Gecko/20060710 Firefox/51.0.1
• Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8.1.5) Gecko/20070719 Firefox/51.0
• Mozilla/5.0 (Windows; U; Windows NT 6.0; it; rv:1.8.1.9) Gecko/20071025 Firefox/51.0.1
• Mozilla/5.0 (X11; U; Linux i686; rv:1.7.3) Gecko/20040914 Firefox/51.0.1
• Mozilla/5.0 (Android; Mobile; rv:51.0) Gecko/51.0 Firefox/51.0
• Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8.0.6) Gecko/20060728 Firefox/51.0.1
• Mozilla/5.0 (X11; U; Linux i686; en-GB; rv:1.8.1.6) Gecko/20070914 Firefox/51.0.1
• Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.0.6) Gecko/2009020410 Fedora/3.0.6-1.fc9 Firefox/51.0
• Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.0.1) Gecko/2008072610 Firefox/51.0
• Mozilla/5.0 (Windows NT 10.0; rv:51.0) Gecko/20100101 Firefox/51.0 anonymized by Abelssoft 905094394
• Mozilla/5.0 (Windows; U; Windows NT 5.1; fa; rv:1.9.1.7) Gecko/20091221 Firefox/51.0.1
• Mozilla/5.0 (Windows NT 10.0; Win64; x64; WOW64; rv:41.0) Gecko/20100101 Firefox/51.0.1 (x64 de) Anonymisiert durch AlMiSoft Browser-Anonymisierer 71618530
• Mozilla/5.0 (Windows; U; Windows NT 5.1; es-ES; rv:1.8.0.2) Gecko/20060308 Firefox/51.0
• Mozilla/5.0 (X11; U; OpenBSD sparc64; en-AU; rv:1.8.1.6) Gecko/20071225 Firefox/51.0
• Mozilla/5.0 (Android 4.1.1; Tablet; rv:51.0) Gecko/51.0 Firefox/51.0
• Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.0.13) Gecko/2009080315 Ubuntu/9.04 (jaunty) Firefox/51.0
• Mozilla/5.0 (Android 7.0; Mobile; rv:53.0) Gecko/51.0 Firefox/51.0
• Mozilla/5.0 (Android 5.0; Mobile; rv:51.0) Gecko/51.0 Firefox/51.0
• Mozilla/5.0 (X11; U; Linux i686; en-GB; rv:1.8.1b1) Gecko/20060710 Firefox/51.0