Download Stylus for Firefox. Redesign your favorite websites with Stylus, an actively developed and community driven userstyles manager. Easily install custom themes from popular online repositories, or create, edit, and manage your own personalized CSS stylesheets. Enterprise: - A number of bug fixes and new policies have been implemented in the latest version of Firefox. You can see more details in the Firefox for Enterprise 80 Release Notes. Today’s release is the final scheduled for Firefox 68 ESR (68.12) unless there is a critical security issue found prior to the release of Firefox ESR 78.3 on.
Check your Firefox version (in the “About Firefox” window) and look for “(32-bit)” or “(64-bit)” after the version number: If you see “(32-bit)” and you are running Firefox 56.0 or older, updating to the latest Firefox version should automatically upgrade you to 64-bit. Firefox Developer Edition. Get the Firefox browser built just for developers. Check out the home for web developer resources. Firefox Reality. Explore the web with the Firefox browser for virtual reality. Donate your voice so the future of the web can hear everyone.
Firefox for Android is a free and open-source web browser developed by Mozilla for Android smartphones and tablet computers.As with its PC version, it uses the Gecko layout engine, and supports features such as synchronization with Firefox Sync, blocking web trackers, and add-ons. The initial version of Firefox for Android was codenamed Fennec and branded Firefox for mobile; it initially.
This schedule is based on the current RapidRelease plan. Future dates may change if the process changes. Code is not always released to users on the same day as the branch migration. The release to users may be a few days later, to allow for manual testing and sign-off. Thunderbird tracks the ESR schedule column per Thunderbird release info.
Calendars
Firefox Versiones
This wiki page may not always have the most current information. Please refer to one of the following calendars for up-to-date scheduling:
- Firefox Merge/Release Dates (ICS for Thunderbird/Lightning or your calendar app) (low noise)
- Firefox Merge/Release Full Scheduling Calendar (ICS) (highly detailed - 99.99% up to date)
Future branch dates
| Quarter | Soft Freeze | Merge Date | Nightly | Beta | Release Date | Release | ESR |
|---|---|---|---|---|---|---|---|
| Q2 2021 | 2021-05-27 | 2021-05-31 | Firefox 91 | Firefox 90 | 2021-06-01 | Firefox 89 | Firefox 78.11 |
| 2021-06-24 | 2021-06-28 | Firefox 92 | Firefox 91 | 2021-06-29 | Firefox 90 | Firefox 78.12 | |
| Q3 2021 | 2021-07-22 | 2021-07-26 | Firefox 93 | Firefox 92 | 2021-07-27 | Firefox 91 | Firefox 78.13; 91.0 |
| 2021-08-19 | 2021-08-23 | Firefox 94 | Firefox 93 | 2021-08-24 | Firefox 92 | Firefox 78.14; 91.1 | |
| 2021-09-16 | 2021-09-20 | Firefox 95 | Firefox 94 | 2021-09-21 | Firefox 93 | Firefox 78.15; 91.2 | |
| Q4 2021 | 2021-10-14 | 2021-10-18 | Firefox 96 | Firefox 95 | 2021-10-19 | Firefox 94 | Firefox 91.3 |
| 2021-11-11 | 2021-11-15 | Firefox 97 | Firefox 96 | 2021-11-16 | Firefox 95 | Firefox 91.4 | |
| 2021-12-09 | 2021-12-13 | Firefox 98 | Firefox 97 | 2021-12-14 | Firefox 96 | Firefox 91.5 | |
| Q1 2022 | 2022-01-20 | 2022-01-24 | Firefox 99 | Firefox 98 | 2022-01-25 | Firefox 97 | Firefox 91.6 |
The Nightly soft freeze is typically during the week prior to merge day. During this period high-risk patches should avoid landing until after the Nightly version bump lands on mozilla-central on merge day.
Past branch dates
More details on contents of releases can be found in the release notes archive or Wikipedia: Firefox version history.
| Soft Freeze | Merge Date | Central | Beta | Release Date | Release | ESR |
|---|---|---|---|---|---|---|
| 2021-04-15 | 2021-04-19 | Firefox 90 | Firefox 89 | 2021-04-19 | Firefox 88 | Firefox 78.10 |
| 2021-03-18 | 2021-03-22 | Firefox 89 | Firefox 88 | 2021-03-23 | Firefox 87 | Firefox 78.9 |
| 2021-02-18 | 2021-02-22 | Firefox 88 | Firefox 87 | 2021-02-23 | Firefox 86 | Firefox 78.8 |
| 2021-01-21 | 2021-01-25 | Firefox 87 | Firefox 86 | 2021-01-26 | Firefox 85 | Firefox 78.7 |
| 2020-12-10 | 2020-12-14 | Firefox 86 | Firefox 85 | 2020-12-15 | Firefox 84 | Firefox 78.6 |
| 2020-11-12 | 2020-11-16 | Firefox 85 | Firefox 84 | 2020-11-17 | Firefox 83 | Firefox 78.5 |
| 2020-10-15 | 2020-10-19 | Firefox 84 | Firefox 83 | 2020-10-20 | Firefox 82 | Firefox 78.4 |
| 2020-09-17 | 2020-09-21 | Firefox 83 | Firefox 82 | 2020-09-22 | Firefox 81 | Firefox 78.3 |
| 2020-08-20 | 2020-08-24 | Firefox 82 | Firefox 81 | 2020-08-25 | Firefox 80 | Firefox 68.12; 78.2 |
| 2020-07-23 | 2020-07-27 | Firefox 81 | Firefox 80 | 2020-07-28 | Firefox 79 | Firefox 68.11; 78.1 |
| 2020-06-26 | 2020-06-29 | Firefox 80 | Firefox 79 | 2020-06-30 | Firefox 78 | Firefox 68.10; 78.0 |
| 2020-05-28 | 2020-06-01 | Firefox 79 | Firefox 78 | 2020-06-02 | Firefox 77 | Firefox 68.9 |
| 2020-04-30 | 2020-05-04 | Firefox 78 | Firefox 77 | 2020-05-05 | Firefox 76 | Firefox 68.8 |
| 2020-04-02 | 2020-04-06 | Firefox 77 | Firefox 76 | 2020-04-07 | Firefox 75 | Firefox 68.7 |
| 2020-03-05 | 2020-03-09 | Firefox 76 | Firefox 75 | 2020-03-10 | Firefox 74 | Firefox 68.6 |
| 2020-02-06 | 2020-02-10 | Firefox 75 | Firefox 74 | 2020-02-11 | Firefox 73 | Firefox 68.5 |
| 2020-01-02 | 2020-01-06 | Firefox 74 | Firefox 73 | 2020-01-07 | Firefox 72 | Firefox 68.4 |
| 2019-11-25 | 2019-12-02 | Firefox 73 | Firefox 72 | 2019-12-03 | Firefox 71 | Firefox 68.3 |
| 2019-10-14 | 2019-10-21 | Firefox 72 | Firefox 71 | 2019-10-22 | Firefox 70 | Firefox 68.2 |
| 2019-08-26 | 2019-09-02 | Firefox 71 | Firefox 70 | 2019-09-03 | Firefox 69 | Firefox 60.9; 68.1 |
| 2019-07-01 | 2019-07-08 | Firefox 70 | Firefox 69 | 2019-07-09 | Firefox 68 | Firefox 60.8; 68.0 |
| 2019-05-13 | 2019-05-20 | Firefox 69 | Firefox 68 | 2019-05-21 | Firefox 67 | Firefox 60.7 |
| 2019-03-11 | 2019-03-18 | Firefox 68 | Firefox 67 | 2019-03-19 | Firefox 66 | Firefox 60.6 |
| 2019-01-21 | 2019-01-28 | Firefox 67 | Firefox 66 | 2019-01-29 | Firefox 65 | Firefox 60.5 |
| 2018-12-03 | 2018-12-10 | Firefox 66 | Firefox 65 | 2018-12-11 | Firefox 64 | Firefox 60.4 |
| 2018-10-15 | 2018-10-22 | Firefox 65 | Firefox 64 | 2018-10-23 | Firefox 63 | Firefox 60.3 |
| Merge Date | Central | Beta | Release Date | Release | ESR |
|---|---|---|---|---|---|
| 2018-09-04 | Firefox 64 | Firefox 63 | 2018-09-05 | Firefox 62 | Firefox 60.2 |
| 2018-06-25 | Firefox 63 | Firefox 62 | 2018-06-26 | Firefox 61 | Firefox 52.9; 60.1 |
| 2018-05-07 | Firefox 62 | Firefox 61 | 2018-05-09 | Firefox 60 | Firefox 52.8; 60.0 |
| 2018-03-12 | Firefox 61 | Firefox 60 | 2018-03-13 | Firefox 59 | Firefox 52.7 |
| 2018-01-22 | Firefox 60 | Firefox 59 | 2018-01-23 | Firefox 58 | Firefox 52.6 |
| 2017-11-13 | Firefox 59 | Firefox 58 | 2017-11-14 | Firefox 57 | Firefox 52.5 |
| 2017-09-21 | Firefox 58 | Firefox 57 | 2017-09-28 | Firefox 56 | Firefox 52.4 |
| 2017-08-02 | Firefox 57 | Firefox 56 | 2017-08-08 | Firefox 55 | Firefox 52.3 |
| 2017-06-12 | Firefox 56 | Firefox 55 | 2017-06-13 | Firefox 54 | Firefox 52.2 |
| 2017-04-18 | Firefox 55 | Firefox 54 | 2017-04-19 | Firefox 53 | Firefox 45.9; 52.1 |
| Merge Date | Central | Aurora | Beta | Release Date | Release | ESR |
|---|---|---|---|---|---|---|
| 2017-03-06 | Firefox 55 | Firefox 54 | Firefox 53 | 2017-03-07 | Firefox 52 | Firefox 45.8; 52.0 |
| 2017-01-23 | Firefox 54 | Firefox 53 | Firefox 52 | 2017-01-24 | Firefox 51 | Firefox 45.7 |
| 2016-12-13 | Firefox 50.1.0 | Firefox 45.6 | ||||
| 2016-11-14 | Firefox 53 | Firefox 52 | Firefox 51 | 2016-11-15 | Firefox 50 | Firefox 45.5 |
| 2016-09-19 | Firefox 52 | Firefox 51 | Firefox 50 | 2016-09-20 | Firefox 49 | Firefox 45.4 |
| 2016-08-01 | Firefox 51 | Firefox 50 | Firefox 49 | 2016-08-02 | Firefox 48 | Firefox 45.3 |
| 2016-06-06 | Firefox 50 | Firefox 49 | Firefox 48 | 2016-06-07 | Firefox 47 | Firefox 45.2 |
| 2016-04-25 | Firefox 49 | Firefox 48 | Firefox 47 | 2016-04-26 | Firefox 46 | Firefox 38.8; 45.1 |
| 2016-03-07 | Firefox 48 | Firefox 47 | Firefox 46 | 2016-03-08 | Firefox 45 | Firefox 38.7; 45.0 |
| 2016-01-25 | Firefox 47 | Firefox 46 | Firefox 45 | 2016-01-26 | Firefox 44 | Firefox 38.6 |
| 2015-12-14 | Firefox 46 | Firefox 45 | Firefox 44 | 2015-12-15 | Firefox 43 | Firefox 38.5 |
| 2015-10-29 | Firefox 45 | Firefox 44 | Firefox 43 | 2015-11-03 | Firefox 42 | Firefox 38.4 |
| 2015-09-21 | Firefox 44 | Firefox 43 | Firefox 42 | 2015-09-22 | Firefox 41 | Firefox 38.3 |
| 2015-08-10 | Firefox 43 | Firefox 42 | Firefox 41 | 2015-08-11 | Firefox 40 | Firefox 38.2 |
| 2015-06-29 | Firefox 42 | Firefox 41 | Firefox 40 | 2015-06-30 | Firefox 39 | Firefox 31.8; 38.1 |
| 2015-06-02 | Firefox 38.0.5 | |||||
| 2015-05-11* | Firefox 41 | Firefox 40 | Firefox 39 | 2015-05-12* | Firefox 38 | Firefox 31.7; 38.0 |
| 2015-03-30* | Firefox 40 | Firefox 39 | Firefox 38 | 2015-03-31* | Firefox 37 | Firefox 31.6 |
| 2015-02-23 | Firefox 39 | Firefox 38 | Firefox 37 | 2015-02-24 | Firefox 36 | Firefox 31.5 |
| 2015-01-12* | Firefox 38 | Firefox 37 | Firefox 36 | 2015-01-13* | Firefox 35 | Firefox 31.4 |
| 2014-11-28* | Firefox 37 | Firefox 36 | Firefox 35 | 2014-12-01* | Firefox 34 | Firefox 31.3 |
| 2014-10-13 | Firefox 36 | Firefox 35 | Firefox 34 | 2014-10-14 | Firefox 33 | Firefox 31.2 |
| 2014-09-02* | Firefox 35 | Firefox 34 | Firefox 33 | 2014-09-02 | Firefox 32 | Firefox 24.8; 31.1 |
| 2014-07-21 | Firefox 34 | Firefox 33 | Firefox 32 | 2014-07-22 | Firefox 31 | Firefox 24.7; 31.0 |
| 2014-06-09 | Firefox 33 | Firefox 32 | Firefox 31 | 2014-06-10 | Firefox 30 | Firefox 24.6 |
| 2014-04-28 | Firefox 32 | Firefox 31 | Firefox 30 | 2014-04-29 | Firefox 29 | Firefox 24.5 |
| 2014-03-17 | Firefox 31 | Firefox 30 | Firefox 29 | 2014-03-18 | Firefox 28 | Firefox 24.4 |
| 2014-02-03* | Firefox 30 | Firefox 29 | Firefox 28 | 2014-02-04* | Firefox 27 | Firefox 24.3 |
| 2013-12-09 | Firefox 29 | Firefox 28 | Firefox 27 | 2013-12-10 | Firefox 26 | Firefox 24.2 |
| 2013-10-28 | Firefox 28 | Firefox 27 | Firefox 26 | 2013-10-29 | Firefox 25 | Firefox 17.0.10; 24.1 |
| 2013-09-16 | Firefox 27 | Firefox 26 | Firefox 25 | 2013-09-17 | Firefox 24 | Firefox 17.0.9; 24.0 |
| 2013-08-05 | Firefox 26 | Firefox 25 | Firefox 24 | 2013-08-06 | Firefox 23 | Firefox 17.0.8 |
| 2013-06-24 | Firefox 25 | Firefox 24 | Firefox 23 | 2013-06-25 | Firefox 22 | Firefox 17.0.7 |
| 2013-05-13 | Firefox 24 | Firefox 23 | Firefox 22 | 2013-05-14 | Firefox 21 | Firefox 17.0.6 |
| 2013-04-01 | Firefox 23 | Firefox 22 | Firefox 21 | 2013-04-02 | Firefox 20 | Firefox 17.0.5 |
| 2013-02-19* | Firefox 22 | Firefox 21 | Firefox 20 | 2013-02-19 | Firefox 19 | Firefox 17.0.3 |
| 2013-01-07* | Firefox 21 | Firefox 20 | Firefox 19 | 2013-01-08* | Firefox 18 | Firefox 10.0.12; 17.0.2 |
| 2012-11-19 | Firefox 20 | Firefox 19 | Firefox 18 | 2012-11-20 | Firefox 17 | Firefox 10.0.11; 17.0 |
| 2012-10-08 | Firefox 19 | Firefox 18 | Firefox 17 | 2012-10-09 | Firefox 16 | Firefox 10.0.8 |
| 2012-08-27 | Firefox 18 | Firefox 17 | Firefox 16 | 2012-08-28 | Firefox 15 | Firefox 10.0.7 |
| 2012-07-16 | Firefox 17 | Firefox 16 | Firefox 15 | 2012-07-17 | Firefox 14 | Firefox 10.0.6 |
| 2012-06-05 | Firefox 16 | Firefox 15 | Firefox 14 | 2012-06-05 | Firefox 13 | Firefox 10.0.5 |
| 2012-04-24 | Firefox 15 | Firefox 14 | Firefox 13 | 2012-04-24 | Firefox 12 | Firefox 10.0.4 |
| 2012-03-13 | Firefox 14 | Firefox 13 | Firefox 12 | 2012-03-13 | Firefox 11 | Firefox 10.0.3 |
| 2012-01-31 | Firefox 13 | Firefox 12 | Firefox 11 | 2012-01-31 | Firefox 10 | Firefox 10.0 |
| 2011-12-20 | Firefox 12 | Firefox 11 | Firefox 10 | 2011-12-20 | Firefox 9 | |
| 2011-11-08 | Firefox 11 | Firefox 10 | Firefox 9 | 2011-11-08 | Firefox 8 | |
| 2011-09-27 | Firefox 10 | Firefox 9 | Firefox 8 | 2011-09-27 | Firefox 7 | |
| 2011-08-16 | Firefox 9 | Firefox 8 | Firefox 7 | 2011-08-16 | Firefox 6 | |
| 2011-07-05 | Firefox 8 | Firefox 7 | Firefox 6 | |||
| 2011-06-21 | Firefox 5 | |||||
| 2011-05-24 | Firefox 7 | Firefox 6 | ||||
| 2011-05-17 | Firefox 5 | |||||
| 2011-04-12 | Firefox 6 | Firefox 5 |
*Some release dates and merge dates are rescheduled to avoid conflicts with holidays.
Notes:
- Four week schedule starting late 2019.
- Irregular schedule targeting six to eight week intervals, adjusting for holidays, starting 2016.
- Six week schedule from 2011 to 2015 (with some dates delayed to avoid conflicts with holidays).
- Firefox 5 was on a slightly different schedule. It spent five weeks each on Aurora and Beta while later releases spent six weeks on each branch.
Translation(s): English - Español - Français - Italiano - Русский
Mozilla Firefox, or simply Firefox, is a free and open-source web browser developed by the Mozilla Foundation and its subsidiary, Mozilla Corporation. Firefox is available for many Operating Systems, on desktop and mobile.
Contents
- Installing Firefox
- Profile
Latest Firefox Version
Installing Firefox
From Debian packages
On DebianStable, Install the firefox-esr package.
This installs the Extended Support Release of Firefox. ESRs are not updated with new features every six weeks. They are instead supported for more than a year, updating with major security or stability fixes.
Support for languages other than English is available in packages named firefox-esr-l10n*.
On DebianUnstable, to install the Release version of Firefox, install the firefox package.
From Mozilla binaries
Mozilla distributes ready-to-use Firefox binaries for Linux on their website:
https://www.mozilla.org/en-US/firefox/ - Release
https://www.mozilla.org/en-US/firefox/channel/desktop/#beta - Beta
https://www.mozilla.org/en-US/firefox/channel/desktop/#nightly - Nightly
To install any of them on DebianStable:
- Download the Firefox version you want directly from the official website
- Uncompress the archives:
in the /opt directory (system-wide installation - requires Root privileges)
- in your home directory (install only for the current user)
Create a file firefox-stable.desktop (replace stable with beta or nightly if needed) with the contents below:
in the /usr/share/applications directory (system-wide installation - requires Root privileges)
in the ~/.local/share/applications directory (install only for the current user)
Replace /opt/firefox with the path to the directory where you extracted the archive.
If you want to be able to launch Firefox from a CommandLineInterface, create a symlink to the firefox executable in /usr/local/bin/. For example: sudo ln -s /opt/firefox/firefox /usr/local/bin/firefox
If you want to use your manually installed Firefox as the default DebianAlternatives browser (x-www-browser), run sudo update-alternatives --install /usr/bin/x-www-browser x-www-browser /opt/firefox/firefox 200 && sudo update-alternatives --set x-www-browser /opt/firefox/firefox
From Flathub
Mozilla provides an official FlatPak at FlatHub.
If you haven't already set up flatpak, run
Install it:
Run it:
If you have added /var/lib/flatpak/exports/bin to your PATH, you can also run it with the command
If you want to use your Firefox flatpak as the default DebianAlternatives browser (x-www-browser), run
Flatpaks don't support native messaging. Therefore, add-ons which rely on it such as KeePassXC Browser don't work. A workaround for KeePassXC is described in the Flathub forum. Since the KeePassXC's socket has been renamed in KeePassXC 2.6, for this version you need to tweak the solution as described in comment #3
Using snap
Mozilla provides an official Snap package for Firefox:
If you haven't already installed snapd, run
Install it:
Run it:
Snap packages don't support native messaging. Therefore, add-ons which rely on it such as KeePassXC Browser don't work. Since KeePassXC's server socket has been renamed, you need to tweak the workaround as explained in https://discourse.flathub.org/t/how-to-run-firefox-and-keepassxc-in-a-flatpak-and-get-the-keepassxc-browser-add-on-to-work/437/3?u=jro
Profile
Firefox user data (your home page, toolbars, installed extensions, passwords, bookmarks...) are stored in a profile folder. (See this Mozilla support page).
~/.mozilla/firefox/: location of profile directorie, for flatpak installations, it is ~/.var/app/org.mozilla.firefox/.mozilla/firefox/
/etc/firefox-esr/default/profile/: Files to copy to newly created profiles. Use this location to preconfigure Firefox.
~/.mozilla/firefox/*.*/user.js: firefox preferences for each profile. These preferences can also be set from the browser interface, or from the about:config page.
/etc/firefox-esr/firefox-esr.js: default Firefox system-wide preferences. Each profile/user can override these preferences.
You can start the Profile Manager from Firefox or from the command line: firefox --no-remote -P
* If firefox refuses to start with the existing profile because the version of firefox launched is supposedly not compatible, you can try removing the file compatibility.ini within the profiles directory. You may want to back up the profiles directory first, in case of an actual incompatibility.
or, if you are using flatpak
Disabling automatic connections
Firefox Version 86
Firefox makes a number of automated connections to Mozilla's (and other's) servers without explicitly asking the user for approval. Mozilla documents that list in the How to stop Firefox from making automatic connections page. Here is a table of the above parameters and how Debian diverges from the upstream default:
The table below may be out of date. It was created on 2018-09-23 from the upstream page by looking at an empty profile on Firefox ESR 60.2.1esr-1. Mozilla's documentation itself may be missing some parameters as well.
Feature | Parameter | Mozilla | Debian |
Auto-update checking | app.update.enabled | true | false |
Auto-update search engines | browser.search.update | true | true |
Blocklist updating | extensions.blocklist.enabled | true | true |
Anti-phishing and malware protection lists | browser.safebrowsing.downloads.remote.enabled | true | true |
Tracking protection | privacy.trackingprotection.enabled | false | false |
Secure website certificates (OCSP) | security.OCSP.enabled | 1 | 1 |
Link prefetching | network.prefetch-next | true | true |
DNS prefetching | network.dns.disablePrefetch | false (means enabled) | false |
Speculative pre-connections | network.http.speculative-parallel-limit | 6 | 0 |
Add-on list prefetching | N/A (can't be turned off) | enabled | enabled |
Extensions update check | extensions.update.enabled | true | true |
Live Bookmarks updating | N/A (user-enabled) | none by default | none by default |
Downloads restarted | N/A (user-enabled) | N/A | N/A |
Search plugin icon loading | ? | ? | ? |
Firefox Sync | ? (needs user to opt-in) | N/A | N/A |
Snippets | browser.aboutHomeSnippets.updateUrl | enabled | enabled |
Geolocation for default search engine | browser.search.geoip.url | enabled | enabled |
'What's new' page | browser.startup.homepage_override.mstone | enabled | enabled |
Add-on metadata updating | extensions.getAddons.cache.enabled | enabled | enabled |
Telemetry | browser.selfsupport.url | N/A? | N/A? |
Telemetry | toolkit.telemetry.enabled | false in releases, true in nightly | false? there are other parameters |
toolkit.telemetry.coverage.opt-out | not present (means enabled) | not present | |
OpenH264 plugin download | media.gmp-gmpopenh264.enabled | true | false |
WebRTC | multiple | enabled | enabled? |
Send Video To Device | browser.casting.enabled | false | N/A? |
Captive portal detection | network.captive-portal-service.enabled | true | true |
Loopback connection | can't be disabled | disabled on Linux | disabled |
Other projects aim at improving security and privacy in Firefox:
TorBrowser - Firefox-based Web browser aimed at defending against tracking, surveillance, and censorship.
https://github.com/pyllyukko/user.js - Firefox configuration hardening
https://gitlab.com/anarcat/scripts/blob/master/firefox-tmp - Anarcat's firefox-tmp script
Plugins
The only plugin supported by Firefox is FlashPlayer (NPAPI version). Other plugins are no longer supported.
Plugins are found at /usr/lib/mozilla/plugins (system wide) or ~/.mozilla/plugins (current user only).
Troubleshooting
Firefox is consistently crashing on a website:
Run firefox in safe mode (extensions and themes disabled): firefox --safe-mode
- If this fixes the problem, one of your extensions is the root cause, if not:
Create a new firefox profile: firefox --no-remote -P (or from the about:profiles page)
No sound:
Go through the general Sound troubleshooting steps. If this fails, reinstall alsa and pulseaudio:
Firefox Version 12
Iceweasel
From Debian Etch through Debian Jessie (9th June 2016), Mozilla Firefox was not available in Debian with the official name or branding. Instead, Debian shipped a free-software version rebranded by Debian, named Iceweasel. This fork was maintained because of a disagreement with Mozilla regarding backporting of the security fixes to DebianStable, and as the result could not use trademarked Mozilla artwork.
Starting from DebianStretch, the iceweasel package has been made a transitional package for firefox-esr. Normal Debian support policies, including patches for bug fixes, apply to the package.
https://lists.debian.org/debian-devel/2006/10/msg00665.html - Will IceWeasel be based on a fork or on vanilla FireFox?
https://lwn.net/Articles/676799/ - The end of the Iceweasel Age
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=815006 - Renaming Iceweasel to Firefox
Iceweasel used to require gstreamer1.0-libav gstreamer1.0-plugins-good packages for good video playback support.
External links
Mozilla Firefox Homepage
Debian Mozilla Team
Firefox - Arch Wiki
#debian-mozillaIRC channel
CategoryWebBrowser | CategorySoftware | CategoryNetworkApplication | CategoryRedundant: merge relevant info from Mozilla