Releases

Current Releases

Standard support

Based on Gecko 147

Firefox 147.0.3
Based on Gecko 147

Released on 2026-02-03

SeaMonkey 2.144
Based on Gecko 147

Released on 2014-03-19

Based on Gecko 28

Firefox OS 1.3
Based on Gecko 28

Released on 2014-03-17

Based on Gecko 60

Thunderbird 60.87.0
Based on Gecko 60

Released on 2026-02-03

Extended support

Based on Gecko 60

Firefox 60.87.0esr
Based on Gecko 60

Released on 2026-01-13

Upcoming Releases

NOTE: The dates listed in this section refer to the date of the code merge, not the date of release. See the branch migration calendar for more information.

Based on Gecko 148

Firefox 148
Based on Gecko 148

Currently in BETA channel
Moves to RELEASE week of February 24, 2026

Thunderbird 148
Based on Gecko 148

Currently in BETA channel

SeaMonkey 2.145
Based on Gecko 148

Currently in BETA channel
Moves to RELEASE week of February 24, 2026

Based on Gecko 54

Firefox 54
Based on Gecko 54

Currently in AURORA channel
Moves to BETA week of February 24, 2026

Firefox OS 1.4
Based on Gecko 54

Currently in AURORA channel
Moves to BETA week of February 24, 2026

Thunderbird 54
Based on Gecko 54

Currently in EARLYBIRD channel
Moves to BETA week of February 24, 2026

SeaMonkey 2.51
Based on Gecko 54

Currently in AURORA channel
Moves to BETA week of February 24, 2026

Based on Gecko 149

Firefox 149
Based on Gecko 149

Currently in NIGHTLY channel
Moves to BETA week of February 24, 2026

Firefox OS 2.0
Based on Gecko 32

Currently in NIGHTLY channel
Moves to AURORA week of June 10, 2014

Thunderbird 149
Based on Gecko 149

Currently in DAILY channel
Moves to BETA week of February 24, 2026

SeaMonkey 2.146
Based on Gecko 149

Currently in NIGHTLY channel
Moves to AURORA week of February 24, 2026

Previous Releases

2014

Release	Date	Notes
SeaMonkey 2.25	March 19	Release Notes
Thunderbird 24.4.0	March 18	Release Notes
Firefox 28.0	March 18	Release Notes
Firefox 24.4.0esr	March 18	Release Notes
Firefox 28.0 for Android	March 18	Release Notes
Firefox 27.0.1	February 13	Release Notes
SeaMonkey 2.24	February 6	Release Notes
Thunderbird 24.3.0	February 4	Release Notes
Firefox 27.0	February 4	Release Notes
Firefox 24.3.0esr	February 4	Release Notes
Firefox 27.0 for Android	February 4	Release Notes

2013 and earlier

For releases prior to 2014, see the archive.

Other Links

This is a page for tracking in-progress releases. For maintenance releases, we use a general checklist to ensure we don't miss anything.

• perhaps you'd like to see who release drivers for various releases are?
• or perhaps you'd like to learn more about the priority rankings we assign to releases?
• you might even wonder how we use flags to manage our releases?
• or what branches exist and when they branched?
• perchance you're confused about update terminology?
• maybe you'd like to know about our various branch support levels?
• perhaps you want to see the RapidRelease Calendar for future aurora merges, beta merges, and releases?
• maybe you are interested in checking the Feature Release Tracker for upcoming features?