Configure Firefox

Similarly to Thunderbird: avoid if possible, prefer the UI.

Do not import anything, do not install recommended extensions, and do not use an online account.

As the option says, open previous windows and tabs. I tend to close the programs I am not currently using, and to shut my devices off when I do not use them, instead of putting them in standby.

Not really necessary, but on Windows, it happened more than once that some update reset the default browser. Thus, it should not hurt to enable this setting if you want to use Firefox as your default browser.

Compared to horizontal tabs, they have the advantage that they have a fixed width. So even when you have a lot of tabs, it is still possible to recognize them and read the titles.

And grouping, at least for me, works for me more effectively, for the same reasons.

Unfortunately, not all sites support or respect that setting.

Set Website appearance to "Dark", and Contrast Control to "Automatic (use system settings)".

I currently use the Dark Reader addon to force every website to use dark mode.

I would vastly prefer such a setting to be integrated into Firefox, but as it is not the case, I need something else.

I thought about using a bookmarklet, but I want most sites to be dark by default; having to execute a bookmarklet manually means I get blinded by a white website in too many instances.

By the way, if you want to improve support for dark pages and printing; it can be done easily by querying the media types ^🗄️, like print (@media print), and if the users prefer a light or dark theme, for example with @media (prefers-color-scheme: light):

99% of things I read on the web are in English.

It is possible to set up a list of multiple languages. I’m not sure if that ever had any upside; I suppose that one of the downsides is that it makes me easier to track, as the languages are sent to the server as an HTTP request.

No need to connect somewhere and download some unnecessary data.

In Firefox home content (the default page for new windows and tabs), I also disable everything: web search, recent activity, and shortcuts. The main reason is that I do not use those; there is already the search bar, history, and bookmarks offering the same functionalities on all pages.

Set the default search engine you prefer; unfortunately, it does not seem to be possible (or at least easy) to change the predefined search engines.

I also disable searching from the URL bar, and either use the search bar or use a keyword.

The search bar can be enabled by customizing the toolbar, but there is no graphical setting for disabling the search from the URL bar.

Here is the relevant about:config setting:

The main reason is that I want predictable behavior. I want the browser to tell me that it could not find a website (either because it does not exist anymore, or because I made a typo) instead of sending the URL to a search engine and showing me some results. And sometimes I want to use a valid URL as a search query, and not to open the URL directly.

Using a separate URL and search bar makes the behaviour more predictable, instead of giving the browser the task to guess if I wrote something to search or open.

I leave the settings "Ask to save passwords" enabled, but I prefer to use an external password manager.

The main reason I keep it enabled is that sometimes an external password manager does not integrate well with some websites. For example, pages that use .htaccess for securing the content trigger a Firefox dialog, instead of a dialog in an HTML page, and so cannot inject the desired functionality.

The password manager I’m using is KeePassXC. There is also an addon, on Debian-based systems, I prefer to install the extension as a system package (webext-keepassxc-browser), so that it is available by default for all instances, and is updated together with other programs.

The main advantage of an external password manager is that it makes backups trivial (just copy the KeePassXC database), and that passwords do not need to be synchronized between browsers, mail clients, and other programs.

There are multiple content managers; uBlock Origin, uMatrix, NoScript

What I am currently using is uBlock Origin.

Although the FBI wrote that an "an ad blocking extension when performing internet searches" ^🗄️ should be preferred for avoiding malicious ads, a content blocker (as uBlock Origin describes itself) is much more than that.

I wish that instead of relying on addons with access to all browsed pages, one could use the built-in functionalities of the browser, but as of today, it’s not the case.

Making a local copy of a website is a recurring topic for me.

Firefox offers a couple of ways to download a webpage.

The first is with the print functionality, Ctrl+P, but then the webpage is saved as a PDF, and depending on the website itself, it might look completely different.

A better approach is to use the "save as" functionality, which creates a local HTML file and a directory containing images, JavaScript files, CSS files, and so on. Unfortunately, this is not good enough most of the time. Multiple files are difficult to handle, plus you often want to strip the JavaScript and have a static file, as in the case of the PDF file.

Formats like MHTML ^🗄️, MAFF ^🗄️ and webarchive ^🗄️ are still not supported by all browsers.

The approach I currently use is to create a self-contained HTML file, with inline images, CSS, and no JavaScript, with the help of the SingleFile addon.

There is also a command-line tool, but as of today, I’ve always used the Firefox addon, as I normally want to see what I am storing, especially since I might want to clean up the page.

I do not use bookmarks as intended that often.

One issue is that often pages change or die.

I see that it is possible to use SingleFile to automatically save a page when creating a bookmark; it is something that I should try out.

What I currently use are bookmarklets. For them, I have the bookmarks menu always visible, so that I can access the most used bookmarklets immediately.

They give me the possibility to extract links, get the RSS feed link, enable copy, archive, or view a page on Internet Archive, and trigger other actions with just one click.

Firefox has supported profiles since the beginning. firefox -P starts the profile manager, otherwise type about:profiles in the URL bar of the current instance of Firefox.

I do not use profiles a lot. Normally, I prefer to use a single instance and containers, but there is a group of sites that I do not visit often, and it makes sense for me to open them either way in a separate window.

Containers are, in my opinion, completely undersold and should be used way more often.

They are more lightweight and better integrated than profiles.

A typical example of how to use a container is given by the addon facebook-container:

I use Multi-Account Containers mainly for websites I log into. Sometimes I want to visit the website while I’m logged in, and sometimes not. Instead of logging in and out every time, I simply choose to open the website in its dedicated container, or not.

And sometimes I have more than one account.

It is possible to achieve something similar with profiles, but it has some drawbacks:

This was a high-level overview of what I should configure when setting up Firefox.

Other browsers, mostly Chromium-based, might have similar settings and addons.