Firefox

Firefox is a graphical web browser developed by Mozilla.

Installation

Set programs.firefox.enable to true in your system or Home Manager configuration. Keep in mind that the NixOS and Home Manager modules have different options, so choose accordingly.

Firefox Variants

There are several Firefox variants that you can choose to install. To choose a variant, set programs.firefox.package accordingly. Note: The packages for the variants listed below are installed instead of the normal firefox package. Thus, you'll have to choose one among these options.

Variant: Official Binaries

Mozilla provides official pre-built Firefox binaries. This is the firefox-bin package and will be downloaded directly from the Mozilla servers.

Variant: Extended Support Release (ESR)

firefox-esr is a variant of Firefox provided by Mozilla, which receives security updates for a longer period of time and a more relaxed cadence of feature implementation. It also allows users to change otherwise untouchable behavior with Firefox using policies.

Variant: Nightly

Nightly builds are daily builds of Firefox from the central Mozilla repository.

Method #1: Using nix-community/flake-firefox-nightly

This method is reproducible but may lag behind the upstream version of Firefox Nightly. It uses flakes.

First, add the following inputs to your flake:

inputs = {
  firefox.url = "github:nix-community/flake-firefox-nightly";
  firefox.inputs.nixpkgs.follows = "nixpkgs";
};

Then, using the specialArgs attribute to pass flake inputs to external configuration files, add the nightly package to your system:

{ pkgs, inputs, config, ... }:
{
  environment.systemPackages = [
    inputs.firefox.packages.${pkgs.system}.firefox-nightly-bin
  ];
}

Method #2: Using mozilla/nixpkgs-mozilla

</translate> This method is not necessarily reproducible without a Flake-like system because it fetches resources from non-pinned URLs, but it will always be the latest Nightly version.

nixpkgs.overlays =
  let
    # Change this to a rev sha to pin
    moz-rev = "master";
    moz-url = builtins.fetchTarball { url = "https://github.com/mozilla/nixpkgs-mozilla/archive/${moz-rev}.tar.gz";};
    nightlyOverlay = (import "${moz-url}/firefox-overlay.nix");
  in [
    nightlyOverlay
  ];
programs.firefox.package = pkgs.latest.firefox-nightly-bin;

It is also needed to pass the --impure option to nix commands. For example,

$ nixos-rebuild switch --impure

Customizing with Home Manager

Home manager allows more customization for firefox. Such as extensions, search engines, bookmarks, userChrome and user.js. The example below shows a basic config defining Nix packages & options as a search engine. More options are available on Home Manager's site

home-manager.users.username = {
  programs.firefox = {
    enable = true;
    profiles = {
      "user" = {
        id = 0;
        isDefault = true;

        search.engines = {
          "Nix Packages" = {
            urls = [{
              template = "https://search.nixos.org/packages";
              params = [
                { name = "query"; value = "{searchTerms}"; }
              ];
            }];
            icon = "${pkgs.nixos-icons}/share/icons/hicolor/scalable/apps/nix-snowflake.svg";
            definedAliases = [ "@np" ];
          };
          "Nix Options" = {
            definedAliases = [ "@no" ];
            urls = [{
              template = "https://search.nixos.org/options";
              params = [
                { name = "query"; value = "{searchTerms}"; }
              ];
            }];
          };
        };
      };
    };
  };

FAQ

How do I use ALSA with Firefox instead of PulseAudio?

programs.firefox.package = (pkgs.wrapFirefox.override { libpulseaudio = pkgs.libpressureaudio; }) pkgs.firefox-unwrapped { };

Tips

=== Enabling Plasma Browser Integration === 1. Add the following line to your configuration.nix (note that enabling Plasma automatically does this):

programs.firefox.nativeMessagingHosts.packages = [ pkgs.plasma5Packages.plasma-browser-integration ];

2. Install KDE's Firefox extension.

Use KDE file picker

You must instruct Firefox to use the file picker offered by the XDG Desktop Portal framework. This setting can be found in Firefox's about:config as widget.use-xdg-desktop-portal.file-picker. The value 1 means "always". To set it using NixOS, add to 'configuration.nix'

  # Make Firefox use the KDE file picker.
  # Preferences source: https://wiki.archlinux.org/title/firefox#KDE_integration
  programs.firefox = {
    enable = true;
    preferences = {
      "widget.use-xdg-desktop-portal.file-picker" = 1;
    };
  };

Use xinput2

You can make Firefox use xinput2 by setting the MOZ_USE_XINPUT2 environment variable. This improves touchscreen support and enables additional touchpad gestures. It also enables smooth scrolling as opposed to the stepped scrolling that Firefox has by default. To do this, put the following in your config:

environment.sessionVariables = {
  MOZ_USE_XINPUT2 = "1";
};

Troubleshooting

nativeMessagingHosts doesn't work

These options, for example enablePlasmaBrowserIntegration, orenableGnomeExtensions, do not work with the bin variants of the Firefox packages or with Firefox installed vianix-env.

---

Screen Sharing under Wayland

When using Firefox with Wayland, screen sharing options might be limited and require additional configuration (exact capabilities vary with different compositors).

• Enable PipeWire

services.pipewire.enable = true;

• Add PipeWire support to Firefox:

programs.firefox.enable = true
programs.firefox.wrapperConfig = {
  pipewireSupport = true;
};

Alternatively, it is possible to override the Firefox derivation with PipeWire support to it:

environment.systemPackages = [
-  pkgs.firefox
+  pkgs.wrapFirefox (pkgs.firefox-unwrapped.override { pipewireSupport = true;}) {})
];

• Enable xdg desktop integration:

xdg = {
  portal = {
    enable = true;
    extraPortals = with pkgs; [
      xdg-desktop-portal-wlr
      xdg-desktop-portal-gtk
    ];
  };
};

• Set environment variables to hint Firefox to use Wayland features. E.g.:

# NixOS setup
environment.sessionVariables = {
  # only needed for Sway
  XDG_CURRENT_DESKTOP = "sway"; 
};

# Home Manager setup
home.sessionVariables = {
  # only needed for Sway
  XDG_CURRENT_DESKTOP = "sway"; 
};

• Ensure that the environment variables are correctly set for the user systemd units, e.g.

1. Sway users might achieve this by adding the following to their Sway config file
2. This ensures all user units started after the command (not those already running) set the variables

exec systemctl --user import-environment