That was complete bullshit, of course. Yes, I absolutely branded Mozilla.org that way for the subtext of "these free software people are all a bunch of commies." I was trolling.

Once upon a time, Mozilla was three commies in a trenchcoat.

Quote from Reddit (as it is not an open media anymore):

I genuinely love Firefox, both as a developer and as an everyday user, and I appreciate the work that goes into it. That being said, Firefox dropped the ball on the new profile management system in about as big a way as possible, and I'm curious if there are other users out there who have developed any workarounds for the issues I've been facing.

The core issue is that Firefox now effectively has two profile systems with overlapping goals and zero interoperability. Profiles created via the new toolbar-based manager don't integrate with about:profiles or the -P switcher. Profiles created via the old system do not appear in the new manager. They coexist but do not talk to each other. Most confusing of all is why Firefox removed the ability to use custom profile directories. As I explain below, this in particular significantly impacts developers.

For power users, this new manager is frustrating. The old profile manager allowed custom directories and could be controlled via profiles.ini and command-line flags. Instead of extending the existing system, Firefox introduced a parallel one with fewer configuration options and no supported way to reconcile the two.

Developers, however, are affected the most. A pretty normal dev workflow involves multiple isolated Firefox profiles, each with different extensions, preferences, and devtools settings, stored in predictable custom directories so they can be launched from VS Code or other editors. It is also very common to open dev profiles side by side with a normal browsing profile for instant comparison. The old system supports this. The new one does not.

What makes this especially frustrating is that I can almost make it work, but it feels like Firefox intentionally designed it not to. The new profile manager uses an SQLite database under the Profile Groups directory. By manually inserting rows into the Profiles table, I was able to import profiles created with the old system:

INSERT INTO "Profiles" VALUES (4,'Profiles\qnx7k4eh.test', 'profile',  'briefcase', 'firefox-compact-dark@mozilla.org', 'rgb(251, 251, 254)',  'rgb(43,42,51)');

At first glance, it works. Profiles created with the old system show up in the new manager, it bypasses the issues with profiles.ini, etc. However, it only works if the profile lives under Firefox’s default profile directory. As soon as the profile exists in a custom path, the new manager refuses to recognize it. Absolute paths and relative traversal paths fail. The database even stores external paths in traversal form like ..\..\..\..\custom\path\profile.default, which strongly suggests the path field is validated and constrained to remain inside a managed root.

This is where the design completely loses me. The new system appears to intentionally restrict all profiles to a single directory with no supported override. The single most important feature for many power users and developers, choosing where their data lives, was deliberately removed.

Developer Edition makes this even worse. The new profile manager forces Developer Edition and Stable to share the same default profile root unless you use the old profile manager. Users cannot cleanly separate everyday browsing profiles from development profiles unless they commit to using two different, incompatible profile management systems. Firefox developers, of all people, should have anticipated that users running Developer Edition do not want profiles mixed with daily browsing, expect separate or at least configurable roots, and are more likely to need automation and custom directory layouts.

The only partial workaround I have found in Windows is using a directory junction. This preserves compatibility with the new manager while allowing a custom directory layout, but it only works on NTFS. If you need cross-platform portability, for example a profile on an exFAT drive shared between Windows and Linux, you're still out of luck.

This is not a case where Firefox made a tradeoff to serve one portion of the user base at the expense of another. If there were a fundamental conflict between a simple system for casual users and a flexible system for developers, that would be understandable. But introducing a new profile management system that cannot see profiles created by the existing one, does not interoperate with -P or about:profiles, cannot support custom directories, and actively blocks common developer workflows makes no sense. Users are forced to choose between control and convenience, and developers get neither.

Wondering if anyone with more insight can explain the reasoning behind this design, and whether there are any plans to unify the legacy and new systems or support custom profile paths in the new manager.

Also curious if anyone has developed a good workaround for the issues?

Mozilla is in a tricky position. It contains both a nonprofit organization dedicated to making the internet a better place for everyone, and a for-profit arm dedicated to, you know, making money. In the best of times, these things feed each other: The company makes great products that advance its goals for the web, and the nonprofit gets to both advocate for a better web and show people what it looks like. But these are not the best of times. Mozilla has spent the last couple of years implementing layoffs and restructuring, attempting to explain how it can fight for privacy and openness when Google pays most of its bills, while trying to find its place in an increasingly frothy AI landscape.

Fun times to be the new Mozilla CEO, right? But when I put all that to Anthony Enzor-DeMeo, the company’s just-announced chief executive, he swears he sees opportunity in all the upheaval. “I think what’s actually needed now is a technology company that people can trust,” Enzor-DeMeo says. “What I’ve seen with AI is an erosion of trust.”

Mozilla is not going to train its own giant LLM anytime soon. But there’s still an AI Mode coming to Firefox next year, which Enzor-DeMeo says will offer users their choice of model and product, all in a browser they can understand and from a company they can trust. “We’re not incentivized to push one model or the other,” he says. “So we’re going to try to go to market with multiple models.”

-_-

Just a bit of a different Firefox.

In a Finnish myth, when an arctic fox runs so fast that its bushy tail brushes the mountains, flaming sparks are cast into the heavens creating the northern lights. In fact the Finnish word "revontulet", a name for the aurora borealis or northern lights, can be translated as fire fox. So that evocative myth took on a special significance for the photographer of this northern night skyscape from Finnish Lapland near Kilpisjarvi Lake. The snowy scene is illuminated by moonlight. Saana, an iconic fell or mountain of Lapland, rises at the right in the background. But as the beautiful nothern lights danced overhead, the wild fire fox in the foreground enthusiastically ran around the photographer and his equipment, making it difficult to capture in this lucky single shot.

There weren't any straightforward guides when I looked this up, and I even had to ask myself. But I just needed to put so and so together, get some feedback here, and voila! Hopefully this can work for you too, and could edit userchrome.css in your favorite editor, and see the changes in Firefox immediately. I tested that it works with @import url("folder/file.css");, and nested imports too (if folder/file.css contained @import url("Another folder/file.css");.

1. Install fx-autoconfig (I haven't tested it with other Firefox JS loaders), following the whole install section: https://github.com/MrOtherGuy/fx-autoconfig?tab=readme-ov-file#install
2. In the chrome/JS/ folder, create <any file name>.uc.mjs (I named mine refresh.uc.mjs) and paste the script below (it's slightly modified from this snippet):
   • The part containing @onlyonce is needed so fx-autoconfig loads it just once, rather than spawn a new instance of the script every time a new firefox window is opened.
3. Clear startup cache: https://github.com/MrOtherGuy/fx-autoconfig?tab=readme-ov-file#deleting-startup-cache
4. You may need to toggle the script. You can go to Menu Bar > Tools > userScripts.

Script

// ==UserScript==
// @onlyonce
// ==/UserScript==

// Script from here:  https://gist.github.com/jscher2000/ad268422c3187dbcbc0d15216a3a8060?permalink_comment_id=3259657#gistcomment-3259657
setInterval(() => {
    /*
       Code to paste and run in the Browser Console
       Requires devtools.chrome.enabled => true in about:config
       Tested in Firefox 68.0.1 on Windows
    */

    // Create references to APIs we'll use
    var ss = Cc["@mozilla.org/content/style-sheet-service;1"].getService(Ci.nsIStyleSheetService);
    var io = Cc["@mozilla.org/network/io-service;1"].getService(Ci.nsIIOService);
    var ds = Cc["@mozilla.org/file/directory_service;1"].getService(Ci.nsIProperties);
      
    // Get the chrome directory in the current profile
    var chromepath = ds.get("UChrm", Ci.nsIFile);

    // Specific file: userChrome.css or userContent.css
    chromepath.append("userChrome.css");

    // Morph to a file URI
    var chromefile = io.newFileURI(chromepath);

    // Unregister the sheet
    if(ss.sheetRegistered(chromefile, ss.USER_SHEET)){
      ss.unregisterSheet(chromefile, ss.USER_SHEET);
    }

    // Reload the sheet
    ss.loadAndRegisterSheet(chromefile, ss.USER_SHEET);
}, 1000)

Especially as demand for video grew, the web needed a next-generation codec to make high-quality streaming faster and more reliable. H.265 promised efficiency gains, but there was no guarantee of another OpenH.264-style arrangement. The risk was another fragmented ecosystem where browsers like Firefox couldn’t play large portions of the web’s video.

To solve this, Mozilla joined other technical leaders to form the Alliance for Open Media (AOM) in 2015 and started ambitious work on a next-generation codec built from Google’s VP9, Mozilla’s Daala, and Cisco’s Thor.

Whenever you open Firefox, we want it to feel like it speaks your language and matches your style. This month, our mobile team is rolling out features inspired by community ideas, user requests and the small everyday moments that make browsing more delightful.

In 2025, we rolled out one update after another, all aimed at making your browsing better — with more flow, speed, choice, and control over your information and experience. Your window to the internet, whether on desktop, mobile, or across all your devices, has gotten an upgrade this year.

Last year, the Firefox team set out to test something fans requested: choosing a custom app icon. The experiment was simple. Offer a small set of options and see how people use them.

https://www.xuldev.org/misc/ucjs.php

EDIT: Has been claimed!

I want to get rid of this poster since I never used it. It's a limited edition print/lithograph from around 2015. 24x36in, 61x91.5cm. If you happen to be in Toronto, Canada you can have it for free if you pick it up, or pay to have it shipped elsewhere.

The text in the corner says:

mozilla
The Web.
A public resource open to all.
Ours to shape and keep free.
To balance the profit of a few
With the benefit of the many.
To know more. Do more. Do better.
This is our mission.

Is this behavior expected? I would imagine it would be a privacy violation in a multi-user system. I thought they had some sort of encryption for hiding the sites that I visit.

BTW, FF does not do this on private mode. But still it is concerning, that any program can know about the sites I visit just by looking at ~/.mozilla/profile/storage/default.

Basically, whenever I edit firefox-profile-path/chrome/userChrome.css, I want firefox to automatically apply the file again. The only posts I found on this are old and not straightforward. I'm wondering what currently works.

I have seen folks talk about a pain point for using FF (or forks) being related to YouTube being super slow. The about:config settings the article mentions did seem to lead to YouTube loading faster on both my FF and Zen-Browser installs. So maybe this might help for others that specifically don't like to use FF as their main browser because of YouTube.

For those that just want the settings:

gfx.webrender.compositor.force-enabled (set to true and restart FF)

If on AMD GPU, this extra setting is supposed to help reduce CPU usage:

media.wmf.zero-copy-nv12-textures-force-enabled (set to true and restart FF)

*edit - per Zak in the comments. The AMD setting is Windows specific.

In March 2024, Mozilla said it was winding down its collaboration with Onerep — an identity protection service offered with the Firefox web browser that promises to remove users from hundreds of people-search sites — after KrebsOnSecurity revealed Onerep’s founder had created dozens of people-search services and was continuing to operate at least one of them. Sixteen months later, however, Mozilla is still promoting Onerep. This week, Mozilla announced its partnership with Onerep will officially end next month.

Our initial subscription tier, the Early Bird Plan, priced at $9 per month, will include all three services: Thundermail, Send, and Appointment. Email hosting, file storage, and the security behind all of this come at a cost, and Thunderbird Pro will never be funded by selling user data, showing ads, or compromising its independence. This introductory rate directly supports Thunderbird Pro’s early development and growth, positioning it for long-term sustainability. We will also be actively listening to your feedback and reviewing the pricing and plans we offer. Once the rough edges are smoothed out and we’re ready to open the doors to everyone, we plan to introduce additional tiers to better meet the needs of all our users.

Be sure you sign up for our Early Bird waitlist at tb.pro and help us shape the future of Thunderbird Pro. See you soon!

Huzzah!

To easy understand what i am saying, i will give you this example, you visit domain.com but on this page there are other things from external domains other than domain.com that firefox fetches/connects to - cdn.blabla.com; third-party.socialwebsites.com, etc. What i want, is to simply not connect to any other domain except what i typed in url bar. I understand it can break pages but i dont care.
A while ago, setting permission.default.images to 2 somehow worked and stopped loading of external content. Disabling prefetch/preconnect/predict/predictor does nothing.
p.s. i dont want to use extensions, only about config.

Very simple + sane extension that I found.

Puts an RSS icon into your URL bar when the webpage you're on has an RSS feed. The button is hidden, if it does not.
When you click the button, it copies the feed URL into your clipboard, so you can add it into your RSS reader. If there's multiple RSS feeds on a webpage, it shows a little dropdown and then when you click one of the entries, it copies the feed URL.

When I say "RSS", I do also mean Atom and possibly others.

I set gfx.wayland.hdr to true and tried opening this video. It says HDR around the cogwheel, but the colors are washed out. With this option disabled the video looks great.

I tried enabling other options, like native_srgb and compositor as suggested online, but no difference.