Firefox 148 adds master switch for browser bot bother

While Thunderbird 148 improves MS Exchange support and sign-on security

It's not the only new feature in Firefox 148 yet one thing is very definitely the big news: the global off switch for its AI features that the company announced earlier this month is now included.

Firefox 148 is out, alongside its counterpart Thunderbird 148 from the Mozilla Foundation's for-profit subsidiary MZLA. Both have improved accessibility support and increased security, however, the big news applies only to Firefox – because happily, Thunderbird still eschews LLM-based "enhancements."

The saga of Mozilla's inclusion of artificial idiocy into its browser has trundled along since Firefox 141 in July 2025. That version introduced an embedded LLM bot to invent names for tab groups, thus demonstrating both the desperation of Silicon Valley tech bros to embed plagiarism bots anywhere they possibly can, and also their complete lack of awareness of the resources the things burn. Within weeks, users started complaining about Firefox scoffing CPU power.

Mozilla management didn't get the hint. The next version added bot-powered link summaries. A little later, an "AI window" was promised, to a chorus of user disapproval and calls for a single universal off switch. Now it's here:

Block AI enhancements

Blocking means you won't see new or current AI enhancements in Firefox, or pop-ups about them. Get more details about what's included and how to control traditional machine learning features, like search suggestions and recommendations.

In the humble opinion of this profoundly AI-skeptical vulture, the best bit is that below the global off switch are five more subsidiary ones:

   •  
On-device AI
        •  
Translations
        •  
Image alt text in Firefox PDF viewer
        •  
Tab group suggestions
        •  
Key points in link previews
        •  
Chatbot in sidebar

These switches let you individually toggle specific LLM-based features back on again even if the global AI button is turned off. We've chosen to re-enable the local language translation feature, which debuted in Firefox 139 in May 2025 – we do find that useful from time to time.

To be honest, it's not quite as good as the big remote translation engine of Google Translate. As far as we can tell, The Register first mentioned that in 2008, and it's only improved since. It switched to a new neural net model in 2016, got a newer one in 2022, another upgrade in 2023, lots more languages in 2024, and it's a legitimately useful tool. For us, automated translation is the single best application of LLMs – and we have no problem with the inclusion of a local one for that. It's the rest of it we don't want.

There are some other new features too. There's improved HTML sanitization to better block cross-site scripting attacks. You can now disable Mozilla's telemetry and still get what Mozilla terms Remote Improvements – which means you'll still get told about new versions of the browser. Mozilla has its own page of information on its telemetry, and various third-party sites offer guidance on how to turn it off, some of them extremely detailed.

Or, of course, you can switch to a Firefox fork such as Reg FOSS desk favorite Waterfox, whose lack of telemetry protected its users from the Foxstuck bug in 2022.

If you're still using Windows 10 – perhaps via the handy Windows 10 LTSC edition, the IoT edition of which still has a six years of support ahead of it – then Firefox Backup can now save your session details even if you don't use Firefox Sync. And, as ever, there are some changes for developers that will be invisible to most of us.

Thunderbird 148

As usual, the Thunderbird messaging client has been updated as well with some new features and improvements.

Thunderbird 148 changes the supported authentication methods for several types of email account. For those who must work with Microsoft Exchange servers, Thunderbird now supports NTLM authentication as well as other login methods. NTLM is an old Microsoft authentication protocol, and although the company's page about it does not spell this out, the initialism stands for New Technology LAN Manager – in other words, it dates all the way back to the 1990s. It is on its way out but for now it still works, and this may make login simpler for those using Thunderbird on a Windows-based network.

Thunderbird 148 also switches the authentication method for Yahoo, AT&T, and AOL accounts to use PKCE authentication, or Proof Key for Code Exchange, to give its full name. Apparently it's pronounced "pixie," presumably to provide potential for amusing confusion with the Preboot Execution Environment. This vulture has accounts on two of those international services, and had to log into both again once we upgraded.

There's also improved accessibility, better handling of the folder tree, improved handling of favorite destinations, and some 50 or so security fixes. ®