- 1 Installing
- 2 Add-ons
- 3 Plugins
- 4 Configuration
- 5 Tips and tricks
- 6 Troubleshooting
- 6.1 Extension X does not work on some Mozilla owned domains
- 6.2 Firefox startup takes very long
- 6.3 Font troubleshooting
- 6.4 Setting an email client
- 6.5 File association
- 6.6 Firefox keeps creating ~/Desktop even when this is not desired
- 6.7 Make plugins respect blocked pop-ups
- 6.8 Changes to userChrome.css and userContent.css are ignored
- 6.9 Middle-click behavior
- 6.10 Backspace does not work as the 'Back' button
- 6.11 Firefox does not remember login information
- 6.12 Cannot enter/leave fullscreen
- 6.13 Firefox detects the wrong version of my plugin
- 6.15 Firefox does not remember default spell check language
- 6.16 Some MathML symbols are missing
- 6.17 Tearing video in fullscreen mode
- 6.18 Tearing when scrolling
- 6.19 Firefox WebRTC module cannot detect a microphone
- 6.20 Cannot login with my Chinese account
- 6.21 No audio on certain videos when using JACK and PulseAudio
- 6.22 Geolocation does not work
- 6.23 Right mouse button instantly clicks the first option in window managers
- 7 See also
Firefox can be installed with the package.
Other alternatives include:
- Firefox Developer Edition — for developers
- Firefox Extended Support Release — long-term supported version
- https://www.mozilla.org/firefox/organizations/ || AUR or AUR
- Firefox Beta — cutting-edge version
- https://www.mozilla.org/firefox/channel/desktop/#beta || AUR or AUR
- Firefox Nightly — nightly builds for testing (experimental features)
- Firefox KDE — Version of Firefox that incorporates an OpenSUSE patch for better KDE integration than is possible through simple Firefox plugins.
- On top of the different Mozilla build channels, a number of forks exist with more or less special features; see List of applications#Gecko-based.
A number of language packs are available for Firefox, other than the standard English. Language packs are usually named as
languagecode can be any language code, such as de, ja, fr, etc.). For a list of available language packs see firefox-i18n for ,firefox-developer-edition-i18n for and firefox-nightly- for AUR.
Firefox is well known for its large library of add-ons which can be used to add new features or modify the behavior of existing features. Firefox's "Add-ons Manager" is used to manage installed add-ons or find new ones.
For instructions on how to install add-ons and a list of add-ons, see Browser extensions.
Adding search engines
Search engines may be added to Firefox by creating bookmarks with the
Location field using search URLs completed with %s in place of the query and the
Keyword field completed with user-defined characters:
Location: https://duckduckgo.com/html/?q=%s Keyword: d
Searches are performed by pre-pending the search term with the keyword of the specified search engine:
d archwiki will query DuckDuckGo using the search term
Search engines may also be added to Firefox through add-on extensions, see this page for a list of available search tools and engines.
A very extensive list of search engines can be found at the Mycroft Project.
Also, you can use the add-to-searchbar extension to add a search to your search bar from any web site, by simply right clicking on the site's search field and selecting Add to Search Bar...
Install the AUR package to add Arch-specific searches (AUR, wiki, forum, packages, etc) to the Firefox search toolbar.
To find out what plugins are installed/enabled, enter:
in the Firefox address bar or go to the Add-ons entry in the Firefox Menu and select the Plugins tab.
Firefox exposes a number of configuration options. To examine them, enter in the Firefox address bar:
Once set, these affect the user's current profile, and may be synchronized across all devices via Firefox Sync. Please note that only a subset of the
about:config entries are synchronized by this method, and the exact subset may be found by searching for
about:config. Additional preferences and third party preferences may be synchronized by creating new boolean entries prepending the config value with
services.sync.prefs.sync (documentation is still applicable.) To synchronize the whitelist for the extension NoScript:
noscript.sync.enabled must be set to
true to synchronize the remainder of NoScript's preferences via Firefox Sync.
Firefox also allows configuration for a profile via a
user.js file: user.js kept in the profile folder, usually
~/.mozilla/firefox/xxxxxxxx.default/. For a useful starting point, see e.g custom user.js which is targeted at privacy/security conscious users.
One drawback of the above approach is that it is not applied system-wide. Furthermore, this is not useful as a "pre-configuration", since the profile directory is created after first launch of the browser. You can, however, let firefox create a new profile and, after closing it again, copy the contents of an already created profile folder into it.
Sometimes it may be desired to lock certain settings, a feature useful in widespread deployments of customized Firefox. In order to create a system-wide configuration, follow the steps outlined in Locking preferences:
pref("general.config.obscure_value", 0); pref("general.config.filename", "mozilla.cfg");
/usr/lib/firefox/mozilla.cfg (this stores the actual configuration):
// //...your settings... // e.g to disable Pocket, uncomment the following line // lockPref("browser.pocket.enabled", false);
Please note that the first line must contain exactly
//. The syntax of the file is similar to that of
Firefox uses PulseAudio for audio playback and capture. For sound to work, you need to install the package.
In case, for whatever reason, PulseAudio is not an option for you, you can use apulse instead. To make this work, it is necessary to exclude
/dev/snd/ from Firefox' sandboxing by adding it to the comma-separated list in
/dev/snd/is important, otherwise apulse will report "Permission denied" errors.
If you have no audio even when using apulse, try adding
Widevine is a digital rights management tool that Netflix, Amazon Prime Video, and others use to protect their video content. It can be enabled in Preferences > General > Digital Rights Management (DRM) Content. If you visit a Widevine-enabled page when this setting is disabled, Firefox will display a prompt below the address bar asking for permission to install DRM. Approve this and then wait for the "Downloading" bar to disappear, you are now able to watch videos from Widevine protected sites.
It is also required that the private mode browsing is disabled, for the window and in the preferences.
Open With extension
- Install Open With add-on.
- Go to Add-ons > Open With > Preferences.
- Proceed with instructions to install a file in your system and test the installation.
- Click Add browser.
- In the dialog write a name for this menu entry and command to start a video streaming capable player (e.g. /usr/bin/mpv).
- (Optional step) Add needed arguments to the player (e.g. you may want
--force-window --ytdlfor mpv)
- Right click on links or visit pages containing videos. Select newly created entry from Open With's menu and if the site is supported, the player will open as expected.
The same procedure can be used to associate video downloaders such as youtube-dl.
Hardware video acceleration
Before trying VA-API support in Firefox be sure to:
- Install correct VA-API driver for your video card and verify VA-API has been enabled and working correctly, see Hardware video acceleration;
- For Intel graphics, use the i965 driver if your hardware supports it.
- The iHD driver see Bugzilla 1619585). This can be worked around by setting the
0, at the risk of losing sandbox protection. (needed by Broadwell or newer) is currently broken due to sandbox violations caused by the driver (
- Use a compositor that supports hardware acceleration, either:
- Set the following flags in
truein order to enable the use of VA-API with FFmpeg;
falseto disable the internal decoders for VP8/VP9.
- If your hardware doesn't support AV1, you can set
falseto force sites like YouTube provide other formats.
- Run Firefox with the following environment variable enabled:
- In Wayland, with
MOZ_ENABLE_WAYLAND=1, see #Wayland.
- In X.org, with
- In Wayland, with
- You can verify that VA-API is enabled by running Firefox with
MOZ_LOG="PlatformDecoderModule:5"environment variable and check in the log output that VA-API is enabled and used (search for the "VA-API" string) when playing a video for example. Pay attention to these logs as they might indicate that only one of the two possible compositors described before (OpenGL or WebRender) works with VA-API on your particular setup.
- For Intel GPU, the
intel_gpu_toputility from package can be used to monitor the GPU activity during video playback for example.
- To allow hardware decoding in YouTube, the video codec used must be supported by the hardware. The profiles supported by your GPU can be checked with Hardware video acceleration#Verifying VA-API and the YouTube codecs used can be controlled with the h264ify or enhanced-h264ify extensions. Alternatively, you can install AUR.
Firefox can use system-wide installed Hunspell dictionaries as well as dictionaries installed through its own extension system.
To enable spell checking for a specific language right click on any text field and check the Check Spelling box. To select a language for spell checking to you have right click again and select your language from the Languages sub-menu.
When your default language choice does not stick, see #Firefox does not remember default spell check language.
System-wide Hunspell dictionaries
Install Hunspell and its dictionaries for the languages you require.
Dictionaries as extensions
To get more languages right click on any text field and just click Add Dictionaries... and select the dictionary you want to install from the Dictionaries and Language Packs list.
- To bring the KDE look to GTK apps (including Firefox), install and . Afterwards, go to System Settings > Application Style > Configure GNOME/GTK Application Style…. Choose 'Breeze' or 'Breeze-Dark' in 'GTK2 Theme' and 'GTK3 Theme'.
- To use the KDE file selection and print dialogs in Firefox 64 or newer, install
GTK_USE_PORTAL=1to the application startup command.
and , then add
- For integration with KDE MIME type system and file dialog, one can use AUR variant from AUR with OpenSUSE’s patches applied. Alternatively, integration with MIME types can be achieved by creating a symbolic link to the MIME database
~/.config/mimeapps.listfrom the deprecated
~/.local/share/applications/mimeapps.listthat is used by Firefox. See XDG MIME Applications#mimeapps.list.
- Extensions/add-ons may provide additional integration, such as:
- Browser integration in Plasma: requires and the Plasma Integration add-on.
about:config. Note the lowercase 'l' despite the the keychain name having an uppercase 'L' in Seahorse. AUR[
Tips and tricks
If a dark GTK theme is in use (e.g. Arc Dark), it is recommended to start Firefox with a brighter one (e.g. Adwaita). See GTK#Themes and Firefox/Tweaks#Unreadable input fields with dark GTK themes for more information.
Alternatively, starting with Firefox 68 you can make the all Firefox interfaces and even other websites respect dark themes, irrespective of the system GTK theme and Firefox theme. To do this, set
If Firefox is unable to automatically detect the right value, it will default to 60 fps. To manually correct this, set
layout.frame_rate to the refresh rate of your monitor (e.g. 144 for 144 Hz).
New tabs position
To control where new tabs appears (relative or absolute), use
browser.tabs.insertRelatedAfterCurrent. See  for more informations.
Screenshot of webpage
You can Take a Screenshot by either clicking the Page actions button (the three horizontal dots) in the address bar or by right-clicking on the webpage. See  for more information.
As an alternative you can use the screenshot button in the Developer Tools.
More recent versions of Firefox support opting into Wayland via an environment variable.
$ MOZ_ENABLE_WAYLAND=1 firefox
To make this permanent, see Environment variables#Graphical environment and start Firefox via the desktop launcher like you normally would. To verify it worked check the Window Protocol again.
You may enter
about:support in the URL bar to check the Window Protocol. It should say wayland/drm instead of x11 nor xwayland.
Window manager rules
To apply different configurations to Firefox windows, change the WM_CLASS string by using Firefox's
--class option, to a custom one.
To start new Firefox instances, multiple profiles are required. To create a new profile:
$ firefox [--new-instance] -P
Class can be specified when launching Firefox with a not-in-use profile:
$ firefox [--new-instance] -P profile_name --class=class_name
Touchscreen gestures and pixel-perfect trackpad scrolling
To enable touch gestures (like scrolling and pinch-to-zoom) and one-to-one trackpad scrolling (as can be witnessed with GTK3 applications like Nautilus), set the
MOZ_USE_XINPUT2=1 environment variable before starting Firefox.
Multiple home pages
To have multiple tabs opened when starting Firefox open a new window and then open the sites you want to have as "home tabs".
Now go to Preferences > Home and under Homepage and new windows click the Use Current Pages button.
Alternatively go directly to Preferences > Home and now under Homepage and new windows set the first field to Custom URLs.. and enter the pages you want as new home pages in the following format:
Extension X does not work on some Mozilla owned domains
By default extensions will not affect pages designated by
extensions.webextensions.restrictedDomains. If this is not desired, this field can be cleared (special pages such as
about:* will not be affected).
Firefox startup takes very long
If Firefox takes much longer to start up than other browsers, it may be due to lacking configuration of the localhost in
/etc/hosts. See Network configuration#Local network hostname resolution on how to set it up.
See Font configuration.
Firefox has a setting which determines how many replacements it will allow from fontconfig. To allow it to use all your replacement-rules, change
127 (the highest possible value).
Firefox ships with Twemoji Mozilla font. To use system emoji font set
Setting an email client
Inside the browser,
mailto links by default are opened by a web application such as Gmail or Yahoo Mail. To set an external email program, go to Preferences > Applications and modify the action corresponding to the
mailto content type; the file path will need to be designated (e.g.
/usr/bin/kmail for Kmail).
See Default applications.
Firefox keeps creating ~/Desktop even when this is not desired
~/Desktop as the default place for download and upload files. To change it to another folder, set the
XDG_DESKTOP_DIR option as explained in XDG user directories.
Make plugins respect blocked pop-ups
Some plugins can misbehave and bypass the default settings, such as the Flash plugin. You can prevent this by doing the following:
about:configinto the address bar.
- Right-click on the page and select New > Integer.
- Name it
- Set the value to
The possible values are:
0: Allow all popups from plugins.
1: Allow popups, but limit them to
2: Block popups from plugins.
3: Block popups from plugins, even on whitelisted sites.
Changes to userChrome.css and userContent.css are ignored
To use the middle mouse button to paste whatever text has been highlighted/added to the clipboard, as is common in UNIX-like operating systems, set either
middlemouse.contentLoadURL enabled was the default behaviour prior to Firefox 57.
To scroll on middle-click (default for Windows browsers) set
According to MozillaZine, the
Backspace key was mapped based on which platform the browser was running on. As a compromise, this preference was created to allow the
Backspace key to either go back/forward, scroll up/down a page, or do nothing.
Backspace go back one page in the tab's history and
Shift+Backspace go forward, set
To have the
Backspace key scroll up one page and
Shift+Backspace scroll down one page, set
1. Setting this property to any other value will leave the key unmapped (Arch Linux defaults to
2, in other words, it is unmapped by default).
Firefox does not remember login information
It may be due to a corrupted
cookies.sqlite file in Firefox's profile folder. In order to fix this, just rename or remove
cookie.sqlite while Firefox is not running.
Open a terminal of choice and type the following:
$ rm -f ~/.mozilla/firefox/<profile id>.default/cookies.sqlite
The profile id is a random 8 character string.
Restart Firefox and see if it solved the problem.
If it didn't work, check if there exists a
cookies.sqlite.bak file that you could use to manually restore the cookies.
Cannot enter/leave fullscreen
If Firefox detects an EWMH/ICCCM compliant window manager, it will try to send a WM_STATE message to the root window to request Firefox be made to enter (or leave) full-screen mode (as defined by the window manager). Window managers are allowed to ignore it, but if they do, Firefox will assume the request got denied and propagate it to the end user which results in nothing happening. This may result in not being able to full screen a video. A general workaround is to set the
Related bug reports: Bugzilla 1189622.
Firefox detects the wrong version of my plugin
When you close Firefox, the latter saves the current timestamp and version of your plugins inside
pluginreg.dat located in your profile folder, typically in
If you upgraded your plugin when Firefox was still running, you will thus have the wrong information inside that file. The next time you will restart Firefox you will get that message
Firefox has prevented the outdated plugin "XXXX" from running on ... when you will be trying to open content dedicated to that plugin on the web. This problem often appears with the official Adobe Flash Player plugin which has been upgraded while Firefox was still running.
The solution is to remove the file
pluginreg.dat from your profile and that is it. Firefox will not complain about the missing file as it will be recreated the next time Firefox will be closed. 
You can try setting
Firefox does not remember default spell check language
The default spell checking language can be set as follows:
about:configin the address bar.
spellchecker.dictionaryto your language of choice, for instance
- Notice that the for dictionaries installed as a Firefox plugin the notation is
en-GB, and for dictionaries the notation is
When you only have system wide dictionaries installed with dictionary installed as a Firefox plugin. Notice that now you will also have a tab Dictionaries in Add-ons. You may have to change the order of preferred language for displaying pages in
about:preferences#general to make the spell check default to the language of the addon dictionary.
Some MathML symbols are missing
You need some Math fonts, namely Latin Modern Math and STIX (see this MDN page: ), to display MathML correctly.
Tearing video in fullscreen mode
If you are using the Xorg Intel or Nouveau drivers and experience tearing video in fullscreen mode, try Firefox/Tweaks#Enable OpenGL compositor.
Tearing when scrolling
Try disabling smooth scrolling in Preferences > Browsing.
Firefox WebRTC module cannot detect a microphone
WebRTC applications for instance Firefox WebRTC getUserMedia test page say that microphone cannot be found. Issue is reproducible for both ALSA or PulseAudio setup. Firefox debug logs show the following error:
$ NSPR_LOG_MODULES=MediaManager:5,GetUserMedia:5 firefox
... [Unnamed thread 0x7fd7c0654340]: D/GetUserMedia VoEHardware:GetRecordingDeviceName: Failed 1
You can try setting
media.navigator.audio.full_duplex property to
about:config Firefox page and restart Firefox.
This can also help if you are using the PulseAudio module-echo-cancel and Firefox does not recognise the virtual echo canceling source.
Cannot login with my Chinese account
Firefox provides a local service for Chinese users, with a local account totally different from the international one. Firefox installed with the this page, then you can login with your Chinese account now.package uses the international account system by default, to change into the Chinese local service, you should install the add-on manager on
No audio on certain videos when using JACK and PulseAudio
If you are using JACK in combination with PulseAudio and cannot hear any sound on some videos it could be because those videos have mono audio. This happens if your JACK setup uses more than just stereo, but you use normal headphones. To fix this you simply have to connect the
front-center port from the PulseAudio JACK Sink to both
playback_2 ports of the system output.
You can also do this automatically using a script:
#!/bin/sh jack_connect "PulseAudio JACK Sink:front-center" "system:playback_1" jack_connect "PulseAudio JACK Sink:front-center" "system:playback_2"
Keep in mind that the names for the sink and the ports might be different for you. You can check what your JACK setup looks like with a Patchbay like Catia from.
Geolocation does not work
Recently, Google limited the usage its location service for Arch Linux, which causes the following error when geolocation is enabled on a website:
Geolocation error: Unknown error acquiring position. Region-locked services such as Hulu may display a similar error indicating that your location could not be determined even though you've allowed location services for the site.
To avoid these problems, you can switch to use the Mozilla Location Service. In
about:config change the
geo.provider.network.url setting to:
See FS#65241 for more details.
To fix it, navigate to
about:config and change