These new profiles that can be accessed through menu are not exactly sub-profiles, but I think more like sibling-profiles forming a profile group. Profiles in the same group know about each other, so in the UI you can switch between them and I think there are some settings that can be shared between the profiles in the same group.

I don’t know of any plans to deprecate the old profile system, nor about:profiles for managing them.

I would seriously suggest to at least check the last modified time of the file instead of constantly re-computing all the style rules every second. So at the very least:

// store last known modified time
var previousModified = 0;

setInterval(() => {
// ...
chromepath.append("userChrome.css");

// check last modified time before proceeding
var modified = chromepath.lastModifiedTime;
if(modified <= previousModified){ return }
previousModified = modified;

var chromefile = io.newFileURI(chromepath);
// ... 

That Clear cookies and site data... button is only visible if there is data to clear. These screenshots indicate that searx.drgnz.club is not storing any data currently in Firefox, but startpage.com is storing some data in Librewolf - that is assuming that Librewolf also hides the item when there is no data.

I run nightly, not exclusively but pretty close, and I must say Firefox’ nightly builds are pretty damn stable in my experience. For sure, there are situations where some feature y is clearly unfinished, but it’s super rare to face a situation where I would even need to think about working around some issue - such game breaking issues just don’t happen too much at all. Usually, if a build is found to be truly broken (like crashes very often etc.) then nightly updates get paused. I can remember maybe two times that I’ve had to revert to previous build in over ten years because the I had received an update before updates were halted.

I don’t think there a way to open the library to history section via address. Library window history and bookmarks section are the same document, and the buttons that open open library window to history view do it by opening the window with extra window arguments - which you cannot do by simply changing the url.

A possible other option to show history would be to open Firefox view to history section. about:firefoxview#history

There’s also another thing that I don’t think is mentioned yet. The options available in Settings are supported features. If the feature is only available via about:config then there’s a good chance that it is not supported or tested configuration. It might work or it might not, at least not in all scenarios

A subset of “advanced” users might have turned telemetry off so it certainly is skewed somewhat, but I don’t think there a good reason for me to believe that the subset is necessarily that large.

You can hide them with userContent.css - most of the devtools window stuff is styled via userContent.css not userChrome.css.

But there’s a catch.

Browser toolbox is essentially a separate instance of Firefox, running in separate profile so your “normal” user css files don’t apply to it. Thus, you need to first enable the toolbox profile to load it’s own user css files and create them just like you do normally (toggle toolkit.legacyUserProfileCustomizations.stylesheets, create files in chrome/ folder etc.). The toolbox profile is stored inside the regular profile - in a directory chrome_debugger_profile.

To get to about:config of the toolbox profile you need to first open a new main-window for it - one way that works is to click the meatball menu at the top-right of the toolbox window, and select “Documentation…” - that will launch a new window using using the toolbox profile and then you can just open about:config and proceed as usual. Or you can just modify prefs.js of the toolbox profile directly while the toolbox is not running.

Anyway, after you have set up the toolbox window to load user css files, then just slap this to its userContent.css and restart the toolbox:

header.chrome-debug-toolbar{
  display: none !important;
}

But if you’re using the built-in auto-updater (like people tend to do on Windows and macOS), then it happens automatically in the background, unless you tell the auto-updater to not update automatically.

Definitely does not work that way on my Windows 10 installation. When update is available, Firefox will have a “Restart to install updates” in menu button notification - but the files are not replaced on disk until you actually close (or restart) Firefox and thus Firefox continues to work normally.

What can happen though is that if you run another instance (ie. another profile) of Firefox while the first one has “staged” the update then that another instance can trigger the files to actually be replaced on disk but you would very deliberately do that.

Firefox shouldn’t force you to restart and update like that unless something else, such as your package manager, has already replaced the executable files on your disk. In such a scenario Firefox doesn’t have any option except to inform you to restart it (well I guess it could choose to crash). But the mechanism that forced the update is the package manager.

Reader mode can show images as well though. I mean, it isn’t always successful in doing so - probably because there’s about a million different ways a random website could show an image - but reader mode can show images that it thinks are part of the actual content.

Indeed. Also, the auto-open PiP is super nice feature I’ve been using a lot.

I don’t think Firefox Color can do that. At best you could test and set colors using Color, and then export the settings for both as a theme .zip or .xpi files, and then combine the two to a single manifest.json file. Inside the manifest, a "theme" key would be color properties for “normal” theme and "dark_theme" would be for dark-theme. After that you would submit the theme package to get it signed after which it can be installed as a real theme.

I’m not sure if resistFingerprinting does anything to stop websites from uploading whatever data they can get though, I don’t think it does that. And I don’t think it could really do that in the first place since the website could just obfuscate the data and browser wouldn’t know what is sent.

That’s not necessarily a good solution either, because a service could figure out that the source of random fingerprint data likely comes from the same user. Especially if your ip is not changing. It might perhaps be effective if a substantial amount of people were doing it though.

But to generate such random fingerprint is difficult because it consists of many parts and services don’t all build fingerprints the aame way. You could easily randomize e.g. canvas data, but the issue is that if you only randomize one data point then that one random data point pretty uniquely identifies you if your other datapoints are stable. So to be effective you would really need to randomize several different datapoints and that may not be such an easy task since websites could build them in all sorts of ways.

Yeah, regular http cache is indeed a thing. However it’s more complicated because the web server can tell the browser how the returned content should be cached - if at all. So if, say, reddit servers ask the browser to not cache particular resource (for whatever reason) then it won’t be cached. I mean, the browser is free to do as it pleases, but I think in general browsers would do as the server asked and indeed not cache it.

Yup, YT has only shown me a nice “Sign in to confirm you’re not a bot” message for the past week or so. Not because of Firefox or adblockers though, because the same happens on all other browsers and clients as well.

Maybe because of VPN, or who knows what, maybe they are just idiots.

Indeed. I mean, I’m blocking ads as much the next guy and that’s not going to change in any foreseeable future, but I cannot see how introduction of privacy preserving advertising platform could possibly be seen as anything other than an improvement over the current, completely perverse, situation. It would be better for people who don’t block ads, so if this acquisition would advance uses of privacy-respecting advertising systems and simultaneously get some revenue to Mozilla then this sounds quite like a win-win to me.

I don’t. Pretty much everything just goes to other bookmarks. When I want to use them I’ll just type * to urlbar , type something about it and Firefox usually finds the bookmark I wanted.

Yes. I want to have access to both history and bookmarks on all my devices and send specific tabs to other devices. Sync makes these super convenient.