Difference between revisions of "Firefox"

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[[Category:Web browser]]
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[[ar:Firefox]]
 
[[cs:Firefox]]
 
[[cs:Firefox]]
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[[de:Firefox]]
 
[[es:Firefox]]
 
[[es:Firefox]]
 
[[fr:Firefox]]
 
[[fr:Firefox]]
 
[[it:Firefox]]
 
[[it:Firefox]]
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[[ja:Firefox]]
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[[ko:Firefox]]
 
[[ru:Firefox]]
 
[[ru:Firefox]]
[[tr:Firefox]]
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[[zh-hans:Firefox]]
[[zh-CN:Firefox]]
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{{Related articles start}}
[[Category:Web Browser]]
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{{Related|Browser plugins}}
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{{Related|Firefox/Tweaks}}
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{{Related|Firefox/Profile on RAM}}
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{{Related|Firefox/Privacy}}
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{{Related|Chromium}}
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{{Related|Opera}}
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{{Related articles end}}
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[https://www.mozilla.org/firefox Firefox] is a popular open source graphical web browser from [https://www.mozilla.org Mozilla].
  
 +
== Installing ==
 +
 +
Firefox can be [[installed]] with the {{Pkg|firefox}} package.
 +
 +
Other alternatives include:
 +
 +
* {{App|Firefox Developer Edition|for developers|https://www.mozilla.org/firefox/developer/|{{Pkg|firefox-developer-edition}}}}
 +
* {{App|Firefox Extended Support Release|long-term supported version|https://www.mozilla.org/firefox/organizations/|{{AUR|firefox-esr}} or {{AUR|firefox-esr-bin}}}}
 +
* {{App|Firefox Beta|cutting-edge version|https://www.mozilla.org/firefox/channel/desktop/#beta|{{AUR|firefox-beta}} or {{AUR|firefox-beta-bin}}}}
 +
* {{App|Firefox Nightly|nightly builds for testing ([https://developer.mozilla.org/Firefox/Experimental_features experimental features])|https://www.mozilla.org/firefox/channel/desktop/#nightly|{{AUR|firefox-nightly}}}}
 +
* {{App|Firefox KDE|Version of Firefox that incorporates an OpenSUSE patch for better [[#KDE.2FGNOME_integration|KDE integration]] than is possible through simple Firefox plugins.|https://build.opensuse.org/package/show/mozilla:Factory/MozillaFirefox|{{AUR|firefox-kde-opensuse}}}}
 +
* 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 {{ic|firefox-i18n-''languagecode''}} (where {{ic|''languagecode''}} can be any language code, such as '''de''', '''ja''', '''fr''', etc.). For a list of available language packs see [https://www.archlinux.org/packages/extra/any/firefox-i18n/ firefox-i18n] for {{Pkg|firefox}} and [https://www.archlinux.org/packages/community/any/firefox-developer-edition-i18n/ firefox-developer-edition-i18n] for {{Pkg|firefox-developer-edition}}.
 +
 +
== Add-ons ==
 +
 +
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 a list of popular add-ons, see [https://addons.mozilla.org/firefox/extensions/?sort=popular Mozilla's add-on list sorted by popularity]. See also [[Wikipedia:List of Firefox extensions|List of Firefox extensions]] on Wikipedia.
 +
 +
=== Adding search engines ===
 +
 +
Search engines can be added to Firefox through normal add-ons, see [https://addons.mozilla.org/firefox/search-tools/ this page] for a list of available search engines.
 +
 +
A very extensive list of search engines can be found at the [http://mycroftproject.com/ Mycroft Project].
 +
 +
Also, you can use the [https://firefox.maltekraus.de/extensions/add-to-search-bar 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...''
 +
 +
==== arch-firefox-search ====
 +
 +
Install the {{Pkg|arch-firefox-search}} package to add Arch-specific searches (AUR, wiki, forum, etc, as specified by user) to the Firefox search toolbar.
 +
 +
== Configuration ==
 +
 +
Firefox exposes a number of configuration options. To examine them, enter in the Firefox address bar:
 +
 +
about:config
 +
 +
Once set, these affect the user's current profile, and may be synchronized across all devices via [https://www.mozilla.org/firefox/sync/ Firefox Sync]. Please note that only a subset of the {{ic|about:config}} entries are synchronized by this method, and the exact subset may be found by searching for {{ic|services.sync.prefs}} in {{ic|about:config}}. Additional preferences and third party preferences may be synchronized by creating new boolean entries prepending the config value with {{ic|services.sync.prefs.sync}} ([https://developer.mozilla.org/en-US/docs/Archive/Mozilla/Firefox_Sync/Syncing_custom_preferences documentation] is still applicable.) To synchronize the whitelist for the extension [https://addons.mozilla.org/firefox/addon/noscript/ NoScript]:
 +
 +
services.sync.prefs.sync.capability.policy.maonoscript.sites
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 +
The boolean {{ic|noscript.sync.enabled}} must be set to {{ic|true}} to synchronize the remainder of NoScript's preferences via Firefox Sync.
 +
 +
Firefox also allows configuration for a profile via a {{ic|user.js}} file: [http://kb.mozillazine.org/User.js_file user.js] kept in the profile folder, usually {{ic|~/.mozilla/firefox/''xxxxxxxx''.default/}}. For a useful starting point, see e.g [https://github.com/pyllyukko/user.js custom user.js] which is targeted at privacy/security conscious users.
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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, [https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles#w_restoring-a-profile-backup 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 [http://kb.mozillazine.org/Locking_preferences Locking preferences]:
 +
 +
1. Create {{ic|/usr/lib/firefox/defaults/pref/local-settings.js}}:
 +
 +
pref("general.config.obscure_value", 0);
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pref("general.config.filename", "mozilla.cfg");
 +
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2. Create {{ic|/usr/lib/firefox/mozilla.cfg}} (this stores the actual configuration):
  
{{Article summary start}}
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//
{{Article summary text|Installing and troubleshooting the Firefox browser and plugins}}
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//...your settings...
{{Article summary heading|Related}}
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// e.g to disable Pocket, uncomment the following line
{{Article summary wiki|Browser Plugins}}: Acquiring and installing plugins such as [[Flash]]
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// lockPref("browser.pocket.enabled", false);
{{Article summary wiki|Firefox Tweaks}}: Configuration and modifications
 
{{Article summary end}}
 
  
[http://www.firefox.com Firefox] is a popular open-source graphical web browser from [http://www.mozilla.com Mozilla].
+
Please note that the first line must contain exactly {{ic|//}}. The syntax of the file is similar to that of {{ic|user.js}}.
  
== Installing ==
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=== Multimedia playback ===
The {{Pkg|firefox}} package can be found in the [[Official Repositories|official repositories]] and can be installed with [[pacman]].
+
 
 +
Firefox uses [[FFmpeg]] for playing multimedia inside HTML5 {{ic|<audio>}} and {{ic|<video>}} elements. Go to [https://www.youtube.com/html5 YouTube's HTML5 page], [https://www.quirksmode.org/html5/tests/video.html video-test page] or [https://hpr.dogphilosophy.net/test/ audio-test page] to check which formats are actually supported.
 +
 
 +
HTML5 DRM playback is supported by the Google Widevine CDM, it is however not enabled by default. See ''Preferences > General > Digital Rights Management (DRM) Content'' if you want to learn more.
 +
 
 +
See [[Firefox/Tweaks#Enable additional media codecs]] for advanced configuration and enabling support for Widevine (Netflix, Amazon Video, etc.).
  
There are a number of language packs available if English is not your preferred language. To see a list of available language packs, try:
+
Firefox uses [[PulseAudio]] for audio playback and capture. For sound to work, you need to install the {{Pkg|pulseaudio}} package.
{{bc|$ pacman -Ss firefox-i18n}}
 
  
If Firefox does not anti-alias and/or hint your fonts, try to install {{AUR|ttf-win7-fonts}} (preferred) or {{AUR|ttf-ms-fonts}} and take a look at [[Font Configuration]].
+
In case, for whatever reason, [[PulseAudio]] is not an option for you, you can use [[Advanced Linux Sound Architecture#PulseAudio compatibility|apulse]] instead. To make this work, it is necessary to exclude {{ic|/dev/snd/}} from Firefox' sandboxing by adding it to the comma-separated list in {{ic|about:config}}:
  
== Add-ons ==
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security.sandbox.content.write_path_whitelist
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 of Firefox. You can find new add-ons or manage installed add-ons with Firefox's "Add-ons Manager."
 
  
For a list of popular add-ons, see: [https://addons.mozilla.org/en-US/firefox/extensions/?sort=popular Mozilla's add-on list sorted by popularity].
+
{{Note|The trailing slash on {{ic|/dev/snd/}} is important, otherwise ''apulse'' will report "Permission denied" errors.}}
  
== Plugins ==
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If you have no audio even when using ''apulse'', try adding {{ic|16}} to {{ic|security.sandbox.content.syscall_whitelist}} in {{ic|about:config}}.
''See: [[Browser Plugins]]''
 
  
To find out what plugins are installed/enabled, enter:
+
==== Open-with extension ====
about:plugins
 
in the Firefox address bar. Or go to ''Addons'' from the main bar drop downs <!-- I use vimperator so I do not know what's the name --> and select the ''Plugins'' tab.
 
  
=== GNOME integration ===
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# Install [https://addons.mozilla.org/firefox/addon/open-with/ Open-with] add-on.
Install {{AUR|firefox-extension-gnome-keyring-git}} from the [[Arch User Repository|AUR]] to integrate Firefox 3.6.x with Gnome-keyring.
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# Open {{ic|about:openwith}}, select ''Add...''
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# In the dialog select a video streaming capable player (e.g. [[mpv|/usr/bin/mpv]]).
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# (Optional step) Add needed arguments to the player (e.g. you may want {{ic|--force-window --ytdl}} for ''mpv'')
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# (Optional step) Choose how to display the dialogs using the left panel.
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# Right click on links or visit pages containing videos. If the site is supported, the player will open as expected.
  
You can also install {{AUR|firefox-extension-firefoxnotify-git}} to get libnotify/notifyOSD integration.
+
The same procedure can be used to associate video downloaders such as ''youtube-dl''.
  
 
=== Dictionaries for spell checking ===
 
=== Dictionaries for spell checking ===
Right click in any text entry field and add the dictionary for the solicited language. Restart Firefox, and click in a text entry field again to enable spell checking.
 
  
Or get it from pacman:
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{{Out of date|1={{Pkg|firefox}} since version 61.0-1 does not symlink dictionaries to {{ic|/usr/lib/firefox/dictionaries/}}, it sets {{ic|spellchecker.dictionary_path}} instead.[https://git.archlinux.org/svntogit/packages.git/commit/trunk?h=packages/firefox&id=95dd034eb8ae4263b371b074a57762eead705f96]}}
pacman -Ss hunspell
+
 
 +
Install the {{Pkg|hunspell}} package. You also need to install dictionaries for your language, such as {{Pkg|hunspell-fr}} (for the French language) or {{Pkg|hunspell-he}} (for Hebrew).
  
=== Adding Firefox search engines ===
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By default, Firefox will try to symlink all your hunspell dictionaries in {{ic|/usr/lib/firefox/dictionaries/}}. If you want to have less dictionaries offered to you in Firefox, you can remove some of those links. Be aware that it may not stand an upgrade of Firefox.
  
Visit https://addons.mozilla.org/en-US/firefox/browse/type:4/ and install.
+
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.
  
If you want to custom one, take a look at: {{ic|~/.mozilla/firefox/xxx.default/searchplugins/}} where xxx is your profile ID).
+
To get more languages just click ''Add Dictionaries...'' and select the dictionary you want to install from the list.
 +
 +
When your default language choice does not stick, see [[#Firefox does not remember default spell check language]].
 +
 
 +
=== KDE/GNOME integration ===
 +
 
 +
* To bring the [[KDE]] look to GTK apps (including Firefox), [[install]] {{Pkg|breeze-gtk}} and {{Pkg|kde-gtk-config}}. Afterwards, go to ''System Settings > Application Style > GTK''. Be sure to choose 'Breeze' in 'Select a GTK2/GTK3 Theme' and check 'Show icons in GTK buttons' and 'Show icons in GTK'.
 +
* To make the left mouse button warp the scrollbar instead of the middle one on KDE, go to ''System Settings > Application Style > GTK'' and set the checkbox for "Left mouse button warps scrollbar".
 +
* For integration with [[KDE]] mime type system and file dialog, one can use {{AUR|firefox-kde-opensuse}} variant from AUR with OpenSUSE’s patches applied.
 +
* Extensions/add-ons may provide additional integration, such as:
 +
** Browser integration in [[Plasma]]: requires {{Pkg|plasma-browser-integration}} and the [https://addons.mozilla.org/firefox/addon/plasma-integration/ plasma-integration add-on].
 +
** {{AUR|mozilla-extension-gnome-keyring-git}} (all-JavaScript implementation) to integrate Firefox with [[GNOME Keyring]]. To make firefox-gnome-keyring use your login keychain, set {{ic|extensions.gnome-keyring.keyringName}} to {{ic|login}} in {{ic|about:config}}. Note the lowercase 'l' despite the the keychain name having an uppercase 'L' in Seahorse.
 +
 
 +
== Plugins ==
 +
 
 +
{{Note|Firefox [https://support.mozilla.org/en-US/kb/npapi-plugins has removed support] for [[w:NPAPI|NPAPI]] plugins, except for Flash.}}
 +
 
 +
See the main article: [[Browser plugins]]
 +
 
 +
To find out what plugins are installed/enabled, enter:
  
Yet another repository of premade searchbar engines: [http://mycroft.mozdev.org/ http://mycroft.mozdev.org/]
+
about:plugins
  
Also, you can use [https://firefox.maltekraus.de/extensions/add-to-search-bar add-to-searchbar] extension to add a search to your search bar from any web site, like Opera browser.
+
in the Firefox address bar or go to the ''Add-ons'' entry in the Firefox Menu and select the ''Plugins'' tab.
  
====arch-firefox-search====
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== Tips and tricks ==
Adds Arch-specific searches (AUR, wiki, forum, etc, as specified by user) to the Firefox search toolbar.
 
# pacman -S arch-firefox-search
 
  
== Projects related to Firefox ==
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For general enhancements see [[Firefox/Tweaks]], for privacy related enhancements see [[Firefox/Privacy]].
=== Firefox derivatives ===
 
Two different forks of Mozilla Firefox:
 
  
*Debian’s Iceweasel ([[Wikipedia:Iceweasel]]; http://wiki.debian.org/Iceweasel). It is being developed by Debian and is based on 2.0.
+
=== Screenshot of webpage ===
*GNU/IceCat ([[Wikipedia:GNU IceCat]]; AUR: {{AUR|icecat}}) - formerly known as GNU IceWeasel, is a web browser distributed by the GNU Project. IceCat is made entirely of free software. It is compatible with the GNU/Linux operating system and almost all of Firefox's addons. GNU/IceCat really can fully replace Firefox.
 
  
=== Firefox with better KDE integration ===
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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 [https://support.mozilla.org/en-US/kb/firefox-screenshots] for more information.
*{{AUR|firefox-kde-opensuse}}
 
:with OpenSUSE patch, integrates better with KDE. OpenSUSE's patch and integration of Firefox with KDE is considered the best by many users.
 
  
*{{Pkg|kpartsplugin}}
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{{Note|
:This plugin uses KDE's KParts to embed file viewers into non-KDE browsers
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* The ''Save'' button misleadingly uploads your screenshot to a firefox.com subdomain. Set {{ic|extensions.screenshots.upload-disabled}} to {{ic|true}} to disable this behaviour. [https://github.com/mozilla-services/screenshots/issues/3503]
 +
* If you enabled [[Firefox/Privacy#Anti-fingerprinting|privacy.resistFingerprinting]], to take a screenshot of a website using the above method, you need to grant it ''Extract Canvas Data'' permission.
 +
}}
  
*[http://kde-look.org/content/show.php/?content=117962 Oxygen KDE]
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As an alternative you can use the full-page screenshot button in the ''Developer Tools'', which you can open with {{ic|F12}} (you might need to enable the button first).
:This addon provides further integration with KDE's Oxygen theme, color scheme detection, Faenza icons and various customizations.
 
  
 
== Troubleshooting ==
 
== Troubleshooting ==
  
=== Firefox 4 New Menu Bar/Firefox Button ===
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=== Firefox startup takes very long ===
By default, Arch Linux shows the classic layout of the menu bar. To activate the new Firefox 4 layout with the "Firefox" button replacing the menu bar, uncheck View -> Toolbars -> Menubar.
 
  
In GNU/Linux, you will just get a plain grey button instead of the new orange one from Windows. However you can change this to either a Firefox icon or the icon followed by the "Firefox" text.
+
If Firefox takes much longer to start up than other browsers, it may be due to lacking configuration of the localhost in  {{ic|/etc/hosts}}. See [[Network configuration#Local network hostname resolution]] on how to set it up.  
  
Adding the following to your {{ic|~/.mozilla/firefox/userprofile/chrome/userChrome.css}} file will place the icon before the text:
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=== Font troubleshooting ===
{{bc|#appmenu-toolbar-button {
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  list-style-image: url("chrome://branding/content/icon16.png");
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See [[Font configuration]].
}
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}}
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Firefox has a setting which determines how many replacements it will allow from fontconfig. To allow it to use all your replacement-rules, change {{ic|gfx.font_rendering.fontconfig.max_generic_substitutions}} to {{ic|127}} (the highest possible value).
Adding the following to the same file will ''remove'' the "Firefox" text:
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{{bc|#appmenu-toolbar-button > .toolbarbutton-text,
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=== Setting an email client ===
#appmenu-toolbar-button > .toolbarbutton-menu-dropmarker {
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  display: none !important;
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Inside the browser, {{ic|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 {{ic|mailto}} content type; the file path will need to be designated (e.g. {{ic|/usr/bin/kmail}} for Kmail).
}
 
}}
 
  
{{Note|You need to create both the {{ic|chrome}} directory and {{ic|userChrome.css}}, if they do not already exist.}}
+
Outside the browser, {{ic|mailto}} links are handled by the {{ic|x-scheme-handler/mailto}} mime type, which can be easily configured with [[xdg-mime]]. See [[Default applications]] for details and alternatives.
  
=== Open containing folder problems (KDE) ===
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=== File association ===
If Firefox launches something other than your preferred file manager when using the "Open Containing Folder" option in the Downloads manager, make sure you select your file manager of choice (e.g. Dolphin) in KDE's System Settings:
 
:'''System Settings -> Default Applications -> File Manager'''
 
  
If you have already selected your file manager of choice and Cervisia (or a file manager other than your favorite) is opening modify your user's {{ic|~/.local/share/applications/defaults.list}} to include these two lines:
+
See [[Default applications]].
x-directory/normal=kde4-dolphin.desktop;kde4-kfmclient_dir.desktop;
 
inode/directory=kde4-dolphin.desktop;kde4-kfmclient_dir.desktop;kde4-gwenview.desktop;kde4-filelight.desktop;kde4-cervisia.desktop;
 
  
 
=== Firefox keeps creating ~/Desktop even when this is not desired ===
 
=== Firefox keeps creating ~/Desktop even when this is not desired ===
Firefox uses {{ic|~/Desktop}} as the default place for download and upload files. To set it to another folder, create {{ic|~/.config/user-dirs.dirs}} and add:
 
XDG_DESKTOP_DIR="/home/<user>/"
 
XDG_DOWNLOAD_DIR="/home/<user>/<dir>"
 
XDG_TEMPLATES_DIR="/home/<user>/<dir>"
 
XDG_PUBLICSHARE_DIR="/home/<user>/<dir>"
 
XDG_DOCUMENTS_DIR="/home/<user>/<dir>"
 
XDG_MUSIC_DIR="/home/<user>/<dir>"
 
XDG_PICTURES_DIR="/home/<user>/<dir>"
 
XDG_VIDEOS_DIR="/home/<user>/<dir>"
 
Change {{ic|<user>}} and {{ic|<dir>}} to the actual directory.
 
  
=== How to prevent plugins from allowing popups? ===
+
Firefox uses {{ic|~/Desktop}} as the default place for download and upload files. To change it to another folder, set the {{ic|XDG_DESKTOP_DIR}} option as explained in [[XDG user directories]].
Ever wondered why pop-ups appear even though you have blocked them? It seems that the Flash plugin can bypass default settings and annoy us with those pesky pop-ups. Fear not, for we can prevent it from doing that.
+
 
 +
=== 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:
  
To get around it:
+
# Type {{ic|about:config}} into the address bar.
# Type about:config into the Firefox location bar.
+
# Right-click on the page and select ''New > Integer''.
# Right-click on the page and select New and then Integer.
+
# Name it {{ic|privacy.popups.disable_from_plugins}}.
# Name it privacy.popups.disable_from_plugins
+
# Set the value to {{ic|2}}.
# Set the value to 2.
 
  
 
The possible values are:
 
The possible values are:
* 0: Allow all popups from plugins.
 
* 1: Allow popups, but limit them to dom.popup_maximum.
 
* 2: Block popups from plugins.
 
* 3: Block popups from plugins, even on whitelisted sites.
 
  
=== Middle-click errors ===
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* {{ic|'''0'''}}: Allow all popups from plugins.
! The URL is not valid and cannot be loaded.
+
* {{ic|'''1'''}}: Allow popups, but limit them to {{ic|dom.popup_maximum}}.
Another symptom is that middle-clicking results in unexpected behavior, like accessing a random web page.
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* {{ic|'''2'''}}: Block popups from plugins.
 +
* {{ic|'''3'''}}: Block popups from plugins, even on whitelisted sites.
  
The reason stems from the use of the middle mouse buttons in UNIX-like operating systems. The middle mouse button is used to paste whatever text has been highlighted/added to the clipboard. Then there is the possibly conflicting feature in Firefox, which defaults to loading the URL of the corresponding text when the button is depressed. This can be disabled like so:
+
=== Middle-click behavior ===
  
Open the browser, and type the following into the address bar:
+
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 {{ic|middlemouse.contentLoadURL}} or {{ic|middlemouse.paste}} to {{ic|true}} in {{ic|about:config}}. Having {{ic|middlemouse.contentLoadURL}} enabled was the default behaviour prior to Firefox 57.
about:config
 
Search for '''middlemouse.contentLoadURL''' and set it to false.
 
  
Alternatively, having the traditional scroll cursor on middle-click (default behaviour on Windows browsers) can be achieved by searching for '''general.autoScroll''' and setting it to true.
+
To scroll on middle-click (default for Windows browsers) set {{ic|general.autoScroll}} to {{ic|true}}.
  
 
=== Backspace does not work as the 'Back' button ===
 
=== Backspace does not work as the 'Back' button ===
As per [http://ubuntu.wordpress.com/2006/12/21/fix-firefox-backspace-to-take-you-to-the-previous-page/ this article], the feature has been removed in order to fix a bug. Follow the next steps to retain the original behaviour.
 
  
Open the browser and type the following address:
+
According to [http://kb.mozillazine.org/Browser.backspace_action mozillaZine], the {{ic|Backspace}} key was mapped based on which platform the browser was running on. As a compromise, this preference was created to allow the {{ic|Backspace}} key to either go back/forward, scroll up/down a page, or do nothing.
about:config
+
 
Search for '''browser.backspace_action''' and set it to 0 (zero).
+
To make {{ic|Backspace}} behave like the back button and go back one page in the session history, set {{ic|browser.backspace_action}} to {{ic|0}} in {{ic|about:config}}.
 +
 
 +
To have the {{ic|Backspace}} key scroll up one page and {{ic|Shift+Backspace}} scroll down one page, set {{ic|browser.backspace_action}} to {{ic|1}}. Setting this property to any other value will leave the key unmapped (Arch Linux defaults to {{ic|2}}, in other words, it is unmapped by default).
 +
 
 +
=== Firefox does not remember login information ===
  
=== Firefox does not remember login information  ===
+
It may be due to a corrupted {{ic|cookies.sqlite}} file in [https://support.mozilla.org/t5/Firefox/Profiles-Where-Firefox-stores-your-bookmarks-passwords-and-other/ta-p/4608#w_how-do-i-find-my-profile Firefox's profile] folder. In order to fix this, just rename or remove {{ic|cookie.sqlite}} while Firefox is not running.
It may be cause of a corrupted {{ic|cookies.sqlite}} file in [http://support.mozilla.com/en-US/kb/Profiles#How_to_find_your_profile Firefox's profile] folder. In order to fix this, just rename or remove the cookie.sqlite while Firefox is not running.
 
  
 
Open a terminal of choice and type the following:
 
Open a terminal of choice and type the following:
  $ cd ~/.mozilla/firefox/xxxxxxxx.default/
+
 
$ rm -f cookies.sqlite
+
  $ rm -f ~/.mozilla/firefox/<profile id>.default/cookies.sqlite
{{Note|xxxxxxxx represents a random string of 8 characters.}}
+
 
 +
The profile id is a random 8 character string.
  
 
Restart Firefox and see if it solved the problem.
 
Restart Firefox and see if it solved the problem.
  
=== Broken websites / input fields with dark Gtk Themes ===
+
=== "Do you want Firefox to save your tabs for the next time it starts?" dialog does not appear ===
When using a dark [[GTK]] theme, one might encounter Internet pages with unreadable input and text fields (p.e. Amazon - white text on white background). This can happen because the site only sets either background or text color, and Firefox takes the other one from the theme.
+
 
 +
From the [https://support.mozilla.com/en-US/questions/767751 Mozilla support] site:
  
A work around is to explicitly setting standard colours for all web pages in {{ic|~/.mozilla/firefox/.../chrome/userContent.css}}.
+
# Type {{ic|about:config}} in the address bar.
 +
# Set {{ic|browser.warnOnQuit}} to {{ic|true}}.
 +
# Set {{ic|browser.showQuitWarning}} to {{ic|true}}.
  
The following sets input fields to standard black text / white background; both can be overridden by the displayed site, so that colors are seen as intended:
+
=== Silently fails when installing desktop apps from marketplace ===
{{bc|
 
input {
 
    -moz-appearance: none !important;
 
    background-color: white;
 
    color: black;
 
}
 
  
textarea {
+
Installation of apps from Firefox OS Marketplace will silently fail if there is no {{ic|~/.local/share/applications}} folder.
    -moz-appearance: none !important;
+
 
    background-color: white;
+
=== Firefox detects the wrong version of my plugin ===
    color: black;
+
 
}
+
When you close Firefox, the latter saves the current timestamp and version of your plugins inside {{ic|pluginreg.dat}} located in your profile folder, typically in {{ic|~/.mozilla/firefox/''xxxxxxxx''.default/}}.
}}
+
 
This will force the colours ("Allow paged to choose their own colors [..]" setting, in the '''Preferences > Content > Color''' dialog):
+
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 {{ic|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 [[Browser plugins#Adobe Flash Player|Adobe Flash Player plugin]] which has been upgraded while Firefox was still running.
{{bc|
+
 
input {
+
The solution is to remove the file {{ic|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. [https://bugzilla.mozilla.org/show_bug.cgi?id=1109795#c16]
    -moz-appearance: none !important;
 
    background-color: pink !important;
 
    color: green !important;
 
}
 
  
textarea {
+
=== Javascript context menu does not appear on some sites ===
    -moz-appearance: none !important;
 
    background-color: pink !important;
 
    color: green !important;
 
}
 
}}
 
Change color values to suit, or use an add-on like [https://addons.mozilla.org/en-US/firefox/addon/2108 Stylish].
 
  
=== File association problems ===
+
In {{ic|about:config}}, unset the {{ic|dom.w3c_touch_events.enabled}} setting.
For non-[[GNOME]] users, Firefox may not associate file types (in the "Open With" part of the download dialog). Installing {{Pkg|libgnome}} amends the problem:
 
pacman -S libgnome
 
If you are using KDE you can also do the following:
 
ln -s ~/.local/share/applications/mimeapps.list ~/.local/share/applications/mimeinfo.cache
 
From now on Firefox should use the applications which are explicitly set in KDE.
 
  
=== "I'm Feeling Lucky" Mode ===
+
=== Firefox does not remember default spell check language ===
Some search engine has a feeling lucky feature. For example Google has "I'm Feeling Lucky"  and DuckDuckGo has "I'm Feeling Ducky".
 
  
To activate them:
+
The default spell checking language can be set as follows:
# Type "'''about:config'''" in the address bar.
 
# Search for the string '''keyword.url'''
 
# Modify its value (if any) to the URL of the search engine.
 
  
:: For google, set it to:
+
# Type {{ic|about:config}} in the address bar.
:: {{bc|<nowiki>http://www.google.com/search?btnI=I%27m+Feeling+Lucky&q=</nowiki>}}
+
# Set {{ic|spellchecker.dictionary}} to your language of choice, for instance {{ic|en_GB}}.
:: For DuckDuckGo, set it to:
+
# Notice that the for dictionaries installed as a Firefox plugin the notation is {{ic|en-GB}}, and for {{Pkg|hunspell}} dictionaries the notation is {{ic|en_GB}}.
:: {{bc|<nowiki>https://duckduckgo.com/?q=\</nowiki>}}
 
  
=== "Do you want Firefox to save your tabs for the next time it starts?" dialog does not appear ===
+
When you only have system wide dictionaries installed with {{Pkg|hunspell}}, Firefox might not remember your default dictionary language settings. This can be fixed by having at least one [https://addons.mozilla.org/firefox/language-tools/ dictionary] installed as a Firefox plugin. Notice that now you will also have a tab '''Dictionaries''' in '''add-ons'''.
From the [http://support.mozilla.com/en-US/questions/767751 Mozilla Support] site:
 
  
# Type "'''about:config'''" in the address bar.
+
Related questions on the '''StackExchange''' platform: [https://stackoverflow.com/questions/26936792/change-firefox-spell-check-default-language/29446115], [https://stackoverflow.com/questions/21542515/change-default-language-on-firefox/29446353], [https://askubuntu.com/questions/184300/how-can-i-change-firefoxs-default-dictionary/576877]
# Set '''browser.warnOnQuit''' to '''true'''.
 
# Set '''browser.showQuitWarning''' to '''true'''.
 
  
=== Firefox has high CPU usage and feels slow on scrolling with nVidia GPUs ===
+
Related bug reports: [https://bugzilla.mozilla.org/show_bug.cgi?id=776028 Bugzilla 776028], [https://bugs.launchpad.net/ubuntu/+source/firefox/+bug/1026869 Ubuntu bug 1026869]
  
In some cases, forcing the proprietary nVidia driver to store pixmaps in video memory instead of system memory can yield massive improvements in the perceived performance of pixmap-intensive applications like Firefox. Run
+
=== Some MathML symbols are missing ===
  
$ nvidia-settings -a InitialPixmapPlacement=2
+
You need some Math fonts, namely Latin Modern Math and STIX (see this MDN page: [https://developer.mozilla.org/en-US/docs/Mozilla/MathML_Project/Fonts#Linux]), to display MathML correctly.
  
from the terminal; if desired results are achieved add this line to a script and use your desktop environment's autorun facilities to execute it on every startup. Alternatively, add the parameter to your {{ic|~/.nvidia-settings-rc}} and run
+
In Arch Linux, these fonts are provided by {{Pkg|texlive-core}} '''and''' {{Pkg|texlive-fontsextra}}, but they are not available to fontconfig by default. See [[TeX Live#Fonts]] for details. You can also try other [[Fonts#Math|Math fonts]].
  
$ nvidia-settings --load-config-only
+
=== Tearing video in fullscreen mode ===
  
on startup. This setting is documented in [http://cgit.freedesktop.org/~aplattner/nvidia-settings/tree/src/libXNVCtrl/NVCtrl.h?id=b27db3d10d58b821e87fbe3f46166e02dc589855#n2797 nvidia-settings source code]. Make sure you have added other perfomance-improving settings, see [[NVIDIA]].
+
If you are using the Xorg Intel or Nouveau drivers and experience tearing video in fullscreen mode, try [[Firefox tweaks#Enable OpenGL Off-Main-Thread Compositing (OMTC)]].
  
=== Firefox uses ugly fonts on certain webpages ===
+
=== Firefox WebRTC module cannot detect a microphone ===
  
When Firefox uses bitmap fonts, it can happen that on certain webpages the fonts are very ugly (compared to Google Chrome for example):
+
WebRTC applications for instance [https://mozilla.github.io/webrtc-landing/gum_test.html 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:
  
http://i.imgur.com/SMVdi.png vs http://i.imgur.com/jNmxU.png
+
{{hc|1=$ NSPR_LOG_MODULES=MediaManager:5,GetUserMedia:5 firefox|2=
 +
...
 +
[Unnamed thread 0x7fd7c0654340]: D/GetUserMedia  VoEHardware:GetRecordingDeviceName: Failed 1
 +
}}
  
To fix that, just disable bitmap fonts for X:
+
You can try setting {{ic|media.navigator.audio.full_duplex}} property to {{ic|false}} at {{ic|about:config}} Firefox page and restart Firefox.
$ sudo ln -s /etc/fonts/conf.avail/70-no-bitmaps.conf /etc/fonts/conf.d/
 
  
=== The menu can't pop up after updating to Firefox 13 ===
+
This can also help if you are using the PulseAudio [[PulseAudio/Troubleshooting#Enable Echo/Noise-Cancellation|module-echo-cancel]], and Firefox does not recognise the virtual echo canceling source.
  
This problem may happen to some Chinese user who use {{pkg|fcitx}} as an input method. The problem may be caused by false environment variables of fcitx, please check it.
+
== See also ==
Or you may solve it by installing {{pkg|fcitx-gtk2}}, {{pkg|fcitx-gtk3}}, and {{pkg|fcitx-qt}}.
 
  
==See also==
+
* [https://www.mozilla.org/firefox/ Official website]
* [http://web.glandium.org/blog/?p=97 Facts about Debian and Mozilla® Firefox]
+
* [https://www.mozilla.org/ Mozilla Foundation]
:An account of the trademark issues from the Firefox package maintainer for Debian.
+
* [[MozillaWiki:Firefox]]
* [http://www.gnu.org/software/gnuzilla/ Gnuzilla and IceWeasel]
+
* [https://addons.mozilla.org/ Firefox Add-ons]
:Official website for the GNU Mozilla forks.
+
* [https://addons.mozilla.org/firefox/themes/ Firefox themes]
 +
* [[Wikipedia:Mozilla Firefox]]
 +
* [http://forums.mozillazine.org/ mozillaZine] unofficial forums

Latest revision as of 13:50, 3 September 2018

Firefox is a popular open source graphical web browser from Mozilla.

Installing

Firefox can be installed with the firefox package.

Other alternatives include:

  • Firefox Developer Edition — for developers
https://www.mozilla.org/firefox/developer/ || firefox-developer-edition
  • Firefox Extended Support Release — long-term supported version
https://www.mozilla.org/firefox/organizations/ || firefox-esrAUR or firefox-esr-binAUR
  • Firefox Beta — cutting-edge version
https://www.mozilla.org/firefox/channel/desktop/#beta || firefox-betaAUR or firefox-beta-binAUR
https://www.mozilla.org/firefox/channel/desktop/#nightly || firefox-nightlyAUR
  • Firefox KDE — Version of Firefox that incorporates an OpenSUSE patch for better KDE integration than is possible through simple Firefox plugins.
https://build.opensuse.org/package/show/mozilla:Factory/MozillaFirefox || firefox-kde-opensuseAUR

A number of language packs are available for Firefox, other than the standard English. Language packs are usually named as firefox-i18n-languagecode (where languagecode can be any language code, such as de, ja, fr, etc.). For a list of available language packs see firefox-i18n for firefox and firefox-developer-edition-i18n for firefox-developer-edition.

Add-ons

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 a list of popular add-ons, see Mozilla's add-on list sorted by popularity. See also List of Firefox extensions on Wikipedia.

Adding search engines

Search engines can be added to Firefox through normal add-ons, see this page for a list of available search 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...

arch-firefox-search

Install the arch-firefox-search package to add Arch-specific searches (AUR, wiki, forum, etc, as specified by user) to the Firefox search toolbar.

Configuration

Firefox exposes a number of configuration options. To examine them, enter in the Firefox address bar:

about:config

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 services.sync.prefs in 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:

services.sync.prefs.sync.capability.policy.maonoscript.sites

The boolean 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:

1. Create /usr/lib/firefox/defaults/pref/local-settings.js:

pref("general.config.obscure_value", 0);
pref("general.config.filename", "mozilla.cfg");

2. Create /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 user.js.

Multimedia playback

Firefox uses FFmpeg for playing multimedia inside HTML5 <audio> and <video> elements. Go to YouTube's HTML5 page, video-test page or audio-test page to check which formats are actually supported.

HTML5 DRM playback is supported by the Google Widevine CDM, it is however not enabled by default. See Preferences > General > Digital Rights Management (DRM) Content if you want to learn more.

See Firefox/Tweaks#Enable additional media codecs for advanced configuration and enabling support for Widevine (Netflix, Amazon Video, etc.).

Firefox uses PulseAudio for audio playback and capture. For sound to work, you need to install the pulseaudio 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 about:config:

security.sandbox.content.write_path_whitelist
Note: The trailing slash on /dev/snd/ is important, otherwise apulse will report "Permission denied" errors.

If you have no audio even when using apulse, try adding 16 to security.sandbox.content.syscall_whitelist in about:config.

Open-with extension

  1. Install Open-with add-on.
  2. Open about:openwith, select Add...
  3. In the dialog select a video streaming capable player (e.g. /usr/bin/mpv).
  4. (Optional step) Add needed arguments to the player (e.g. you may want --force-window --ytdl for mpv)
  5. (Optional step) Choose how to display the dialogs using the left panel.
  6. Right click on links or visit pages containing videos. 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.

Dictionaries for spell checking

Tango-view-refresh-red.pngThis article or section is out of date.Tango-view-refresh-red.png

Reason: firefox since version 61.0-1 does not symlink dictionaries to /usr/lib/firefox/dictionaries/, it sets spellchecker.dictionary_path instead.[1] (Discuss in Talk:Firefox#)

Install the hunspell package. You also need to install dictionaries for your language, such as hunspell-fr (for the French language) or hunspell-he (for Hebrew).

By default, Firefox will try to symlink all your hunspell dictionaries in /usr/lib/firefox/dictionaries/. If you want to have less dictionaries offered to you in Firefox, you can remove some of those links. Be aware that it may not stand an upgrade of Firefox.

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.

To get more languages just click Add Dictionaries... and select the dictionary you want to install from the list.

When your default language choice does not stick, see #Firefox does not remember default spell check language.

KDE/GNOME integration

  • To bring the KDE look to GTK apps (including Firefox), install breeze-gtk and kde-gtk-config. Afterwards, go to System Settings > Application Style > GTK. Be sure to choose 'Breeze' in 'Select a GTK2/GTK3 Theme' and check 'Show icons in GTK buttons' and 'Show icons in GTK'.
  • To make the left mouse button warp the scrollbar instead of the middle one on KDE, go to System Settings > Application Style > GTK and set the checkbox for "Left mouse button warps scrollbar".
  • For integration with KDE mime type system and file dialog, one can use firefox-kde-opensuseAUR variant from AUR with OpenSUSE’s patches applied.
  • Extensions/add-ons may provide additional integration, such as:

Plugins

Note: Firefox has removed support for NPAPI plugins, except for Flash.

See the main article: Browser plugins

To find out what plugins are installed/enabled, enter:

about:plugins

in the Firefox address bar or go to the Add-ons entry in the Firefox Menu and select the Plugins tab.

Tips and tricks

For general enhancements see Firefox/Tweaks, for privacy related enhancements see Firefox/Privacy.

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 [2] for more information.

Note:
  • The Save button misleadingly uploads your screenshot to a firefox.com subdomain. Set extensions.screenshots.upload-disabled to true to disable this behaviour. [3]
  • If you enabled privacy.resistFingerprinting, to take a screenshot of a website using the above method, you need to grant it Extract Canvas Data permission.

As an alternative you can use the full-page screenshot button in the Developer Tools, which you can open with F12 (you might need to enable the button first).

Troubleshooting

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.

Font troubleshooting

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 gfx.font_rendering.fontconfig.max_generic_substitutions to 127 (the highest possible value).

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).

Outside the browser, mailto links are handled by the x-scheme-handler/mailto mime type, which can be easily configured with xdg-mime. See Default applications for details and alternatives.

File association

See Default applications.

Firefox keeps creating ~/Desktop even when this is not desired

Firefox uses ~/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:

  1. Type about:config into the address bar.
  2. Right-click on the page and select New > Integer.
  3. Name it privacy.popups.disable_from_plugins.
  4. Set the value to 2.

The possible values are:

  • 0: Allow all popups from plugins.
  • 1: Allow popups, but limit them to dom.popup_maximum.
  • 2: Block popups from plugins.
  • 3: Block popups from plugins, even on whitelisted sites.

Middle-click behavior

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 or middlemouse.paste to true in about:config. Having middlemouse.contentLoadURL enabled was the default behaviour prior to Firefox 57.

To scroll on middle-click (default for Windows browsers) set general.autoScroll to true.

Backspace does not work as the 'Back' button

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.

To make Backspace behave like the back button and go back one page in the session history, set browser.backspace_action to 0 in about:config.

To have the Backspace key scroll up one page and Shift+Backspace scroll down one page, set browser.backspace_action to 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.

"Do you want Firefox to save your tabs for the next time it starts?" dialog does not appear

From the Mozilla support site:

  1. Type about:config in the address bar.
  2. Set browser.warnOnQuit to true.
  3. Set browser.showQuitWarning to true.

Silently fails when installing desktop apps from marketplace

Installation of apps from Firefox OS Marketplace will silently fail if there is no ~/.local/share/applications folder.

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 ~/.mozilla/firefox/xxxxxxxx.default/.

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. [4]

Javascript context menu does not appear on some sites

In about:config, unset the dom.w3c_touch_events.enabled setting.

Firefox does not remember default spell check language

The default spell checking language can be set as follows:

  1. Type about:config in the address bar.
  2. Set spellchecker.dictionary to your language of choice, for instance en_GB.
  3. Notice that the for dictionaries installed as a Firefox plugin the notation is en-GB, and for hunspell dictionaries the notation is en_GB.

When you only have system wide dictionaries installed with hunspell, Firefox might not remember your default dictionary language settings. This can be fixed by having at least one dictionary installed as a Firefox plugin. Notice that now you will also have a tab Dictionaries in add-ons.

Related questions on the StackExchange platform: [5], [6], [7]

Related bug reports: Bugzilla 776028, Ubuntu bug 1026869

Some MathML symbols are missing

You need some Math fonts, namely Latin Modern Math and STIX (see this MDN page: [8]), to display MathML correctly.

In Arch Linux, these fonts are provided by texlive-core and texlive-fontsextra, but they are not available to fontconfig by default. See TeX Live#Fonts for details. You can also try other Math fonts.

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 Off-Main-Thread Compositing (OMTC).

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 false at 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.

See also