Firefox version history


Market share overview
According to StatCounter data
January 2026
Browser % of Fx % of total
Firefox 1
Firefox 2
Firefox 3
Firefox 4
Firefox 5–9 0.90% 0.02%
Firefox 10–16 3.15% 0.07%
Firefox 17–23
Firefox 24–30
Firefox 31–37
Firefox 38–44 0.45% 0.01%
Firefox 45–51
Firefox 52–59 0.45% 0.01%
Firefox 60–67
Firefox 68–77
Firefox 78–90
Firefox 91–101
Firefox 102–114 0.45% 0.01%
Firefox 115 and 115 ESR 5.86% 0.13%
Firefox 116
Firefox 117
Firefox 118
Firefox 119
Firefox 120
Firefox 121
Firefox 122
Firefox 123
Firefox 124
Firefox 125
Firefox 126
Firefox 127
Firefox 128–139 0.45% 0.01%
Firefox 140 and 140 ESR 5.41% 0.12%
Firefox 141
Firefox 142
Firefox 143 0.90% 0.02%
Firefox 144 0.45% 0.01%
Firefox 145 1.35% 0.03%
Firefox 146 35.14% 0.78%
Firefox 147 33.33% 0.74%
Firefox 148
All variants 100% 2.22%

Firefox was created by Dave Hyatt and Blake Ross as an experimental branch of the Mozilla Application Suite, first released as Firefox 1.0 on November 9, 2004. Starting with version 5.0, a rapid release cycle was put into effect, resulting in a new major version release every six weeks. This was gradually accelerated further in late 2019, so that new major releases occur on four-week cycles starting in 2020.