Waterfox, a popular fork of Firefox, is saying nay to AI. Considering how unpopular Mozilla's plan to botify its browser has become, this could win the alternative some converts.

The [1]latest post on the Waterfox blog even says right in its URL that it is a "response to Mozilla." In it, lead developer Alex Kontos says:

Waterfox will not include LLMs. Full stop. At least and most definitely not in their current form or for the foreseeable future.

This is, as the URL says, in response to [2]new Mozilla head honcho Anthony Enzor-DeMeo , whose [3]first blog from the role says:

Firefox will grow from a browser into a broader ecosystem of trusted software. Firefox will remain our anchor. It will evolve into a modern AI browser and support a portfolio of new and trusted software additions.

In the words of the late great Douglas Adams, "this has made a lot of people very angry and been widely regarded as a bad move." Many are quoting a [4]Mastodon post from "TheZeldaZone":

"Hello, We're Firefox, The Only Browser That Hasn't Hit Itself In The Dick With A Hammer. For years now, folks use us because of our un-hammered dick. Now, you may be wondering why today we've brought this hammer and pulled out our dick. Well I'm glad you asked–"

Mozilla is not totally oblivious – just [5]dyslexic when it comes to reading the room – and has responded to reactions to the "modern AI browser" statement with a [6]toot of its own from the [7]Firefox for Web Developers account :

Something that hasn't been made clear: Firefox will have an option to completely disable all AI features.

We've been calling it the AI kill switch internally. I'm sure it'll ship with a less murderous name, but that's how seriously and absolutely we're taking this.

It [8]continues :

All AI features will also be opt-in. I think there are some grey areas in what 'opt-in' means to different people (e.g. is a new toolbar button opt-in?), but the kill switch will absolutely remove all that stuff, and never show it in future. That's unambiguous.

As we have [9]described before , Waterfox is one of the Reg FOSS desk's favorite Firefox-based browsers. It originated as a 64-bit rebuild, back when the Mozilla original was 32-bit only. Over time, it evolved. This correspondent has been using it since 2017, which was when the [10]Firefox Quantum project bore fruit in the form of [11]Firefox 57 . Thanks to the then-new Electrolysis architecture, Firefox Quantum was multi-threaded, and thus better able to take advantage of multi-core CPUs.

The problem was encapsulated by the description of the [12]Classic Add-ons Archive :

This catalog contains 93,598 versions of 19,450 Firefox add-ons created by 14,274 developers over the past 15 years using XUL/XPCOM technology before Mozilla decided to ruin the classic extensions ecosystem and go exclusively to WebExtensions.

At the time Firefox 57 came out, this vulture had a carefully assembled collection of nearly 30 extensions, giving Firefox 56 a combined vertical tab bar and bookmarks bar, syncing our bookmarks automatically between machines, doing multi-threaded downloads that could be resumed if they failed, automatically logging in to vexatious sites with [13]shared fake credentials and much more. After Firefox 57, all but two or three trivial ones were gone. So, we switched to Waterfox and got them all back.

[14]Mozilla Corporation installs Firefox driver in CEO reboot

[15]Firefox is fine. The people running it are not

[16]Firefox is dead to me – and I'm not the only one who is fed up

[17]Mozilla's Firefox 145 is heeeeeere: Buffs up privacy, bloats AI

Since Firefox is now 64-bit native, that's no longer a selling point for Waterfox, but there are others. It's based on Mozilla's ESR versions, so it has a more leisurely update schedule than [18]Firefox's decade-old monthly releases . For a long time, it maintained compatibility with XUL addons, which is still available via [19]Waterfox Classic . Now, the mainstream release has had to drop that, but both the main branch and Classic turn off all of Mozilla's telemetry – which made it immune to the [20]Foxstuck bug in 2022 . It has its own integrated vertical tab bar, which it implemented long before Firefox.

For Linux folks using desktops with a global menu bar, such as Xfce, KDE Plasma, and Unity, then Waterfox still works with it – unlike Firefox itself.

There are other Firefox-derived browsers out there, including [21]LibreWolf , [22]Floorp , and the [23]Zen Browser with its [24]impressive browser window tiling . Waterfox remains our go-to, though – and with Mozilla's enthusiasm for automated plagiarism as a service, we suspect more of its fans may start to look elsewhere. ®

[25]

Get our [26]Tech Resources



[1] https://www.waterfox.com/blog/no-ai-here-response-to-mozilla/

[2] https://www.theregister.com/2025/12/16/mozilla_corporation_new_ceo/

[3] https://blog.mozilla.org/en/mozilla/leadership/mozillas-next-chapter-anthony-enzor-demeo-new-ceo/

[4] https://mastodon.social/@TheZeldaZone/114082180124431864

[5] https://www.theregister.com/2025/07/08/firefox_isnt_dead/

[6] https://mastodon.social/@firefoxwebdevs/115740500373677782

[7] https://mastodon.social/@firefoxwebdevs

[8] https://mastodon.social/@firefoxwebdevs/115740500918701463

[9] https://www.theregister.com/2021/11/04/waterfox_firefox_fork/

[10] https://www.theregister.com/2017/03/28/open_source_insider_firefox_upheaval/

[11] https://www.theregister.com/2017/11/10/open_source_insider_firefox_57/

[12] https://github.com/JustOff/ca-archive

[13] https://bugmenot.com/

[14] https://www.theregister.com/2025/12/16/mozilla_corporation_new_ceo/

[15] https://www.theregister.com/2025/07/08/firefox_isnt_dead/

[16] https://www.theregister.com/2025/06/17/opinion_column_firefox/

[17] https://www.theregister.com/2025/11/12/firefox_145_arrives/

[18] https://www.theregister.com/2015/07/07/firefox_development_changes/

[19] https://classic.waterfox.net/

[20] https://www.theregister.com/2022/01/18/foxstuck_firefox_browser_bug_boots/

[21] https://librewolf.net/

[22] https://floorp.app/

[23] https://zen-browser.app/

[24] https://www.theregister.com/2024/09/02/zen_firefox_fork_alpha/

[25] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_software/front&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=2&c=2aUSHh8naMCe6Qb6YOSkkbQAAAUg&t=ct%3Dns%26unitnum%3D2%26raptor%3Dcondor%26pos%3Dtop%26test%3D0

[26] https://whitepapers.theregister.com/