View source for Features of Firefox

{{Short description|Features of the Firefox web browser}}
{{Firefox TOC}}

[[Software:Firefox|Mozilla Firefox]] has features that allow it to be distinguished from other [[Software:Web browser|web browser]]s, such as [[Software:Google Chrome|Chrome]] and [[Software:Internet Explorer|Internet Explorer]].

==Major differences==

To avoid interface bloat, ship a relatively smaller core customizable to meet individual users' needs, and allow for corporate or institutional extensions to meet their varying policies, Firefox relies on a robust extension system to allow users to modify the browser according to their requirements instead of providing all features in the standard distribution.

While [[Software:Opera (web browser)|Opera]] and [[Software:Google Chrome|Google Chrome]] do the same, extensions for these are fewer in number as of late 2013. Internet Explorer also has an extension system but it is less widely supported than that of others. Developers supporting multiple browsers almost always support Firefox, and in many instances exclusively. As Opera has a policy of deliberately including more features in the core as they prove useful, the market for extensions is relatively unstable but also there is less need for them. The sheer number of extensions is not a good guide to the capabilities of a browser.

Protocol support and the difficulty of adding new link type protocols also vary widely across not only these browsers but across versions of these browsers. Opera has historically been most robust and consistent about supporting cutting-edge protocols such as robust file sharing [[EDonkey network|eDonkey]] links or [[Software:Bitcoin|bitcoin]] transactions. These can be difficult to support in Firefox without relying on unknown small developers, which defeats the privacy purpose of these protocols.  Instructions for supporting new link protocols vary widely across operating systems and Firefox versions, and are generally not implementable by end users who lack systems administration comfort and the ability to follow exact detailed instructions to type in strings.

==Web technologies support==
{{Main|Software:Gecko}}

Firefox supports most basic Web standards including [[HTML]], [[XML]], [[XHTML]], [[Cascading Style Sheets|CSS]] (with extensions<ref>{{cite web|url=https://developer.mozilla.org/en/docs/CSS_Reference:Mozilla_Extensions|title=Mozilla CSS extensions|website=MDN Web Docs|access-date=26 June 2018}}</ref>), [[JavaScript]], [[Document Object Model|DOM]], [[MathML]], [[Scalable Vector Graphics|SVG]], [[XSLT]] and [[XPath]].<ref>{{cite web|url=http://www.webdevout.net/browser_support.php|title=Web Browser Standards Support|first=David|last=Hammond|website=www.webdevout.net|access-date=26 June 2018}}</ref> Firefox's standards support and growing popularity have been credited as one reason [[Software:Internet Explorer 7|Internet Explorer 7]] was to be released with improved standards support.<ref>{{cite web | url = http://news.cnet.com/Microsoft+yielding+to+IE+standards+pressure/2100-1032_3-5620988.html | title = Microsoft yielding to IE standards pressure? | author = Paul Festa | work = cNet | access-date = 2006-10-13}}</ref>

Since Web standards are often in contradiction with Internet Explorer's behavior, Firefox, like other browsers, has a [[Quirks mode|quirks mode]]. This mode attempts to mimic Internet Explorer's quirks modes, which equates to using obsolete rendering standards dating back to [[Software:Internet Explorer 5|Internet Explorer 5]], or alternately newer peculiarities introduced in IE [[Software:Internet Explorer 6|6]] or 7.<ref name=ArsTech8>[https://arstechnica.com/articles/paedia/ie8-super-standards-mode.ars Unpacking Internet Explorer 8's multiple rendering modes], Ars Technica.com</ref> However, it is not completely compatible.<ref>{{cite web|url=https://bugzilla.mozilla.org/buglist.cgi?query_format=advanced&short_desc_type=allwordssubstr&short_desc=%5Bquirks%5D&long_desc_type=substring&long_desc=&bug_file_loc_type=allwordssubstr&bug_file_loc=&status_whiteboard_type=allwordssubstr&status_whiteboard=&keywords_type=allwords&keywords=&resolution=---&emailassigned_to1=1&emailtype1=exact&email1=&emailassigned_to2=1&emailreporter2=1&emailqa_contact2=1&emailtype2=exact&email2=&bugidtype=include&bug_id=&votes=&chfieldfrom=&chfieldto=Now&chfieldvalue=&cmdtype=doit&order=Reuse+same+sort+as+last+time&field0-0-0=noop&type0-0-0=noop&value0-0-0=|title=Bug List|website=bugzilla.mozilla.org|access-date=26 June 2018}}</ref> Because of the differing rendering, PC World notes that a minority of pages do not work in Firefox,<ref name="pcworld"/> however Internet Explorer 7's quirks mode does not either.<ref name="ArsTech8"/>

CNET notes that Firefox does not support [[Object Linking and Embedding|ActiveX]] controls by default, which can also cause webpages to be missing features or to not work at all in Firefox.<ref>{{cite web|url=http://reviews.cnet.com/Mozilla_Firefox/4505-9241_7-31117280-4.html?tag=toc|title=c-Net Reviews - Mozilla Firefox|access-date=26 June 2018|archive-url=https://archive.today/20120716003758/http://reviews.cnet.com/Mozilla_Firefox/4505-9241_7-31117280-4.html?tag=toc|archive-date=16 July 2012|url-status=dead}}</ref> Mozilla made the decision to not support ActiveX due to potential security vulnerabilities, its proprietary nature and its lack of cross-platform compatibility.<ref>{{cite web|url=https://www.mozilla.org/security/security-announcement.html|title=Security Announcement|website=www.mozilla.org|access-date=26 June 2018}}</ref><ref>{{cite web|url=https://devedge-temp.mozilla.org/viewsource/2002/gecko-plugins/index_en.html#ActiveX|title=Netscape Gecko Plugin Overview|access-date=26 June 2018}}</ref><ref name="popularity-insecure">{{cite web | url = http://software.silicon.com/applications/0,39024653,39128935,00.htm | title = Popularity won't make Firefox insecure, says Mozilla head | work = silicon.com | author = Michael Kanellos | access-date = 2006-10-13 | archive-url = https://web.archive.org/web/20110521071123/http://www.silicon.com/technology/software/2005/03/23/popularity-wont-make-firefox-insecure-says-mozilla-head-39128935/ | archive-date = 2011-05-21 | url-status = dead }}</ref> There are methods of using ActiveX in Firefox such as via third-party plugins but they do not work in all versions of Firefox or on all platforms.<ref>{{cite web|url=http://www.iol.ie/~locka/mozilla/plugin.htm|title=Mozilla ActiveX Plug-in|website=www.iol.ie|access-date=26 June 2018}}</ref>

Beginning on December 8, 2006, Firefox Nightly builds pass the [[Acid2]] CSS standards compliance test, so all future releases of Firefox 3 would pass the test.<ref>{{cite web | url = https://bugzilla.mozilla.org/show_bug.cgi?id=289480#c121 | title = Mozilla doesn't pass the acid2 (acid 2) test | author = David Baron | access-date = 2006-12-08}}</ref>

Firefox also implements<ref name="mozcomphishff3">{{cite web | title = Phishing and Malware Protection | url = http://www.mozilla.com/en-US/firefox/phishing-protection/ | access-date = 2009-02-27 | publisher = Mozilla Corp.}} (section "How does Phishing and Malware Protection work in Firefox?")</ref> a proprietary protocol<ref name="googsb2prot">{{cite web | title = Client specification for the Google Safe Browsing v2.1 protocol | url = http://code.google.com/p/google-safe-browsing/wiki/Protocolv2Spec | access-date = 2009-02-27 | publisher = Google Inc.}} ''"(...) '''Do not use this protocol without explicit written permission from Google.'''"'', ''"'''Note''': This is not a license to use the defined protocol. (...)"''</ref> from Google called "safebrowsing", which is not an [[Engineering:Open standard|open standard]].

==Cross-platform support==
{| class="wikitable floatright" style="text-align:center;"
|-
! colspan="2"|Unsupported versions for old operating systems
! Version
|-
| rowspan="3"|[[Company:Apple Inc.|Apple]]<br />[[Software:Mac OS X|Mac OS X]]
| v10.1
| 1.0.8
|-
| v10.2-10.3
| 2.0.0.20
|-
| v10.4-10.5 (PPC)
| 3.6.28<ref name="sysreq">{{cite web
|url = http://www.mozilla.com/en-US/firefox/system-requirements.html
|title      = Firefox 3.6 System Requirements
|publisher  = Mozilla
|access-date = 2010-06-22
}}</ref>
|-
| colspan="2"|OS/2 and [[Software:EComStation|eComStation]]
| 3.5.4<ref>{{cite web|url=https://www.mozilla.org/ports/os2/|title=Ports/os2 - MozillaWiki|website=www.mozilla.org|access-date=26 June 2018}}</ref>
|-
| rowspan="3"|[[Company:Microsoft|Microsoft]]<br />[[Software:Microsoft Windows|Windows]]
| [[Software:Windows 95|95]]
| 1.5.0.12
|-
| [[Software:Windows NT 4.0|NT 4]]/[[Software:Windows 98|98]]/ME
| 2.0.0.20
|-
| [[Software:Windows 2000|2000]]
| 12.0 and 10.0.12esr
|}

Mozilla Firefox runs on certain platforms that coincide OS versions in use at the time of release. In 2004 version 1 supported older operating systems such as Windows 95 and Mac OS X 10.1, by 2008 version 3 required at least OS X 10.4 and even Windows 98 support ended.

Various releases available on the primary distribution site can support the following operating systems, although not always the latest Firefox version.
* Various versions of [[Software:Microsoft Windows|Microsoft Windows]], including [[Software:Windows 98|98]], 98SE, ME, [[Software:Windows NT|NT]] 4.0, [[Software:Windows 2000|2000]], [[Software:Windows XP|XP]], [[Software:Windows Server 2003|Server 2003]], [[Software:Windows Vista|Vista]], [[Software:Windows 7|7]], [[Software:Windows 8|8]] and [[Software:Windows 10|10]].
* [[Software:OS X|OS X]]
* [[Software:Linux|Linux]]-based operating systems using [[Software:X.Org Server|X.Org Server]] or [[Software:XFree86|XFree86]]

Builds for [[Software:Solaris (operating system)|Solaris]] (x86 and SPARC), contributed by the [[Company:Sun Microsystems|Sun]] Beijing Desktop Team, are available on the Mozilla web site.<ref>{{cite web
|url = http://www.mozilla.com/en-US/firefox/all.html
|title = Firefox - All Downloads
|access-date = 2007-06-30
|publisher = Mozilla
}} Follow link on bottom of page reading "Unsupported versions of Firefox for other platforms are also available"</ref>

Mozilla Firefox 1.x installation on [[Software:Windows 95|Windows 95]] requires [http://johnhaller.com/jh/mozilla/windows_95/ a few additional steps].

Since Firefox is [[Open-source license|open source]] and Mozilla actively develops a [[Mozilla application framework|platform independent abstraction]] for its [[Graphical user interface|graphical front end]], it can also be compiled and run on a variety of other architectures and operating systems. Thus, Firefox is also available for many other systems. This includes OS/2, AIX, and [[Software:FreeBSD|FreeBSD]]. Builds for [[Software:Windows XP Professional x64 Edition|Windows XP Professional x64 Edition]] are also available. Mozilla Firefox is also the browser of choice for a good number of smaller operating systems, such as [[Software:SkyOS|SkyOS]] and [[Software:Magnussoft ZETA|ZETA]].

Firefox uses the same profile format on the different platforms, so a profile may be used on multiple platforms, if all of the platforms can access the same profile; this includes, for example, profiles stored on an [[NTFS]] (via [[Software:Filesystem in Userspace|FUSE]]) or [[File Allocation Table|FAT32]] partition accessible from both Windows and Linux, or on a [[Engineering:USB flash drive|USB flash drive]]. This is useful for users who dual-boot their machines. However, it may cause a few problems, especially with extensions.

==Security==
Firefox is free-libre software, and thus in particular its source code is visible to everyone. This allows anyone to review the code for security vulnerabilities.<ref>{{cite web | url = http://articles.techrepublic.com.com/5100-10877-6064734.html | title = Security through visibility: The secrets of open source security | author = Chad Perrin | work = TechRepublic | access-date = 2006-10-17}}</ref> It also allowed the U.S. Department of Homeland Security to give funding for the automated tool [[Company:Coverity|Coverity]] to be run against Firefox code.<ref>{{cite web | url = http://news.cnet.com/Homeland+Security+helps+secure+open-source+code/2100-1002_3-6025579.html | title = Homeland Security helps secure open-source code | work = cNet | author = Joris Evers | access-date = 2006-10-13}}</ref>

Additionally, Mozilla has a security bug bounty system - anyone who reports a valid critical security bug receives a $3000 (US) cash reward for each report and a Mozilla T-shirt.<ref>{{cite web | url = https://www.mozilla.org/security/bug-bounty.html | title = Mozilla Security Bug Bounty Program | work = Mozilla | access-date = 2006-10-13 | url-status = dead | archive-url = https://web.archive.org/web/20071125104648/http://www.mozilla.org/security/bug-bounty.html | archive-date = 2007-11-25 }}</ref> With effect from December 15, 2010, Mozilla added Web Applications to its Security Bug Bounty Program.<ref>{{cite web |title=Mozilla adds Web Applications to its Security Bug Bounty Program |url=https://pcsite.co.uk/mozilla-adds-web-applications-to-its-security-bug-bounty-program/ |access-date=2010-12-15 |work=PcSite}}</ref><ref>{{cite web | url = http://blog.mozilla.com/security/2010/12/14/adding-web-applications-to-the-security-bug-bounty-program/ | title = Adding Web Applications to the Security Bug Bounty Program | work = Mozilla Blog | date = 14 December 2010 | access-date = 2010-12-15}}</ref>

==Tabbed browsing==<!-- This section is linked from [[Software:Mozilla Firefox|Mozilla Firefox]] -->
[[Image:Firefox 2 Tabbed Browsing GNU-Linux.png|thumb|right|300px|An example of Firefox with three tabs]]
Firefox supports tabbed browsing, which allows users to open several pages in one window. This feature was carried over from the [[Software:Mozilla Application Suite|Mozilla Application Suite]], which in turn had borrowed the feature from the popular [http://multizilla.mozdev.org MultiZilla] {{Webarchive|url=https://web.archive.org/web/20171014182623/http://multizilla.mozdev.org/ |date=2017-10-14 }} extension for Mozilla.

Firefox also permits the "homepage" to be a list of [[URL]]s delimited with [[Vertical bar|vertical bar]]s (|), which are automatically opened in separate tabs, rather than a single page.

Firefox 2 supports more tabbed browsing features, including a "tab overflow" solution that keeps the user's tabs easily accessible when they would otherwise become illegible, a "session store" which lets the user keep the opened tabs across the restarts, and an "undo close tab" feature.

The tab browsing feature allows users to open multiple tabs or pages on one window. This is convenient for users who enjoy browsing from one window and is also advantageous in ensuring ease of browsing. The tabs are easily made accessible and users can close tabs that are not in use for better usability.

==Pop-up blocking==
Firefox also includes integrated customizable pop-up blocking. Firefox was given this feature early in beta development, and it was a major comparative selling point of the browser until Internet Explorer gained the capability in the Windows XP SP2 release of August 25, 2004. Firefox's pop-up blocking can be turned off entirely to allow pop-ups from all sites. Firefox's pop-up blocking can be inconvenient at times &mdash; it prevents [[JavaScript]]-based links from opening a new window while a page is loading unless the site is added to a "safe list" found in the options menu.

In many cases, it is possible to view the pop-up's URL by clicking the dialog that appears when one is blocked. This makes it easier to decide if the pop-up should be displayed.

==Private browsing==
Private browsing was introduced in Firefox 3.5, which released on June 30, 2009. This feature lets users browse the Internet without leaving any traces in the browsing history.

==Download manager==
[[Image:Firefox-download-manager.png|right|thumb|Firefox 3.0.8 Download Manager]]
An integrated customizable download manager is also included. Downloads can be opened automatically depending on the file type, or saved directly to a disk. By default, Firefox downloads all files to a user's desktop on Mac and Windows or to the user's home directory on Linux, but it can be configured to prompt for a specific download location. Version 3.0 added support for cross-session resuming (stopping a download and resuming it after closing the browser). From within the download manager, a user can view the source [[URL]] from which a download originated as well as the location to which a file was downloaded.

==Live bookmarks==
From 2004, ''live bookmarks'' allowed users to dynamically monitor changes to their favorite news sources, using [[RSS]] or [[Atom (Web standard)|Atom]] feeds. Instead of treating RSS-feeds as HTML pages as most news aggregators do, Firefox treated them as bookmarks and automatically updated them in real-time with a link to the appropriate source. In December 2018, version 64.0 of Firefox removed live bookmarks and web feeds, with Mozilla suggesting its replacement by add-ons or other software with news aggregator functionality like [[Software:Mozilla Thunderbird|Mozilla Thunderbird]].<ref>{{cite web |title=Firefox 64.0, See All New Features, Updates and Fixes |url=https://www.mozilla.org/en-US/firefox/64.0/releasenotes/ |website=Mozilla |date=December 11, 2018 |access-date=December 12, 2018 |language=en-us}}</ref><ref>{{Cite web|title=Feed reader replacements for Firefox|url=https://support.mozilla.org/en-US/kb/feed-reader-replacements-firefox}}</ref>

==Other features==
[[Image:Firefox FAYT.png|thumb|right|Screenshot of performing "Find as you type". "ency" was being typed and the first matched text was highlighted in [[Green|green]].]]

===Find as you type===
Firefox also has an incremental find feature known as "Find as you type", invoked by pressing Ctrl+F. With this feature enabled, a user can simply begin typing a word while viewing a web page, and Firefox automatically searches for it and highlights the first instance found. As the user types more of the word, Firefox refines its search. Also, if the user's exact query does not appear anywhere on the page, the "Find" box turns red. Ctrl+G can be pressed to go to the next found match.
Alternatively the slash (/) key can be used instead to invoke the "quick search". The "quick search", in contrast to the normal search, lacks search controls and is wholly controlled by the keyboard. In this mode highlighted links can be followed by pressing the enter key. The "quick search" has an alternate mode which is invoked by pressing the apostrophe (') key, in this mode only links are matched.

===Mycroft Web Search===
A built-in Mycroft Web search function features extensible search-engine listing; by default, Firefox includes plugins for [[Company:Google|Google]] and [[Company:Yahoo!|Yahoo!]], and also includes plugins for looking up a word on dictionary.com and browsing through Amazon.com listings. Other popular Mycroft search engines include [[Wikipedia]], [[Company:EBay|eBay]], and [[Social:IMDb|IMDb]].

===Smart Bookmarks===
''[[Engineering:Smart Bookmarks|Smart Bookmarks]]'' (aka ''Smart keywords'') can be used to quickly search for information on specific Web sites.<ref>{{cite web
|url = https://www.mozilla.org/products/firefox/smart-keywords.html
|title = What are Smart Keywords?
|access-date = 2007-06-30
|publisher = Mozilla
}}</ref> A smart keyword is defined by the user and can be associated with any bookmark, and can then be used in the [[Address bar|address bar]] as a shortcut to quickly get to the site or, if the smart keyword is linked to a searchbox, to search the site. For example, "imdb" is a pre-defined smart keyword; to search for information about the movie 'Firefox' on [[Social:IMDb|IMDb]], jump to the location bar with the {{key|Ctrl}}+{{key|L}} shortcut, type "imdb Firefox" and press the Enter key or just simply type in "imdb" if one wants to get to the frontpage instead.

===Chrome===
The Chrome packages within Firefox control and implement the Firefox user interface.<ref>
{{Citation
}}
</ref>

==Version 2.0 and above==
{{Main|Software:Firefox 2}}

===Enhanced search capabilities===
Search term suggestions will now appear as users type in the integrated search box when using the Google, Yahoo! or Answers.com search engines. A new search engine manager makes it easier to add, remove and re-order search engines, and users will be alerted when Firefox encounters a website that offers new search engines that the user may wish to install.

===Microsummaries===
Support for '''Microsummaries''' was added in version 2.0. Microsummaries are short summaries of [[Web page|web page]]s that are used to convey more information than page titles. Microsummaries are regularly updated to reflect content changes in web pages so that viewers of the web page will want to revisit the web page after updates. Microsummaries can either be provided by the page, or be generated by the processing of an [[XSLT]] stylesheet against the page. In the latter case, the XSLT stylesheet and the page that the microsummary applies to are provided by a microsummary generator. Support for Microsummaries was removed as of Firefox 6.<ref name="bugzilla.mozilla.org">{{Cite web |url=https://bugzilla.mozilla.org/show_bug.cgi?id=524091 |title=Bug 524091 - Remove microsummaries support. Seldom used, undiscoverable and unmaintained |website=Bugzilla@Mozilla |publisher=Mozilla |date=23 October 2009}}</ref>

===Live Titles===
When a website offers a microsummary (a regularly updated summary of the most important information on a Web page), users can create a bookmark with a "Live Title". Compact enough to fit in the space available to a bookmark label, they provide more useful information about pages than static page titles, and are regularly updated with the latest information. There are [https://wiki.mozilla.org/Microsummaries/Sites several websites] that can be bookmarked with Live Titles, and [https://web.archive.org/web/20080925144944/http://people.mozilla.com/~myk/microsummaries/generators/ even more add-ons] to generate Live Titles for other popular websites. Support for Live Titles was removed as of Firefox 6.<ref name="bugzilla.mozilla.org"/>

===Session Restore===
The Session Restore feature restores windows, tabs, text typed in forms, and in-progress downloads from the last user session. It will be activated automatically when installing an application update or extension, and users will be asked if they want to resume their previous session after a system crash.

===Inline spell checker===
A built-in spell checker enables users to quickly check the spelling of text entered into Web forms without having to use a separate application.

===Usability in version 2===
Firefox 2 was designed for the average user, hiding advanced configuration and making features that do not require user interaction to function.<ref>{{cite web | url = http://weblogs.mozillazine.org/asa/archives/008294.html | title = opera and firefox | access-date = 2006-10-27 | author = Asa Dotzler | archive-url = https://web.archive.org/web/20061016165527/http://weblogs.mozillazine.org/asa/archives/008294.html | archive-date = 2006-10-16 | url-status = dead }}</ref> Jim Repoza of eWEEK states:{{blockquote|eWEEK Labs found Firefox 2.0, which can be downloaded at www.mozilla.com, to have the greatest out-of-the-box usability of any Web browser that we have tested (and that's a lot of Web browsers).<ref>{{cite web | url = http://www.eweek.com/article2/0,1759,2036658,00.asp | title = Firefox 2.0 Balances Innovation with Ease of Use | access-date = 2006-10-27 | author = Jim Repoza | work = eWEEK }}{{Dead link|date=August 2023 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>}} Firefox also won UK Usability Professionals' Association's 2005 award for "Best software application".<ref>{{cite web | url = http://www.usabilitynews.com/news/article2786.asp | title = First UK UPA Awards commend Firefox, Flickr, Google, Apple, John Lewis and BA | access-date = 2006-10-27 | author = Ann Light | work = UsabilityNews.com | archive-date = 2010-01-25 | archive-url = https://web.archive.org/web/20100125054917/http://www.usabilitynews.com/news/article2786.asp | url-status = dead }}</ref>

== Version 3.0 and above ==
{{Main|Software:Firefox 3.0}}

=== Star button ===
Quickly add bookmarks from the location bar with a single click; a second click lets the user file and tag them.

== Version 5.0 and above ==
=== Style Inspector ===
[[File:Page inspector firefox 10.png|thumb|Style Inspector]]
Firefox 10 added the CSS Style Inspector to the Page Inspector, which allow users to check out a site's structure and edit the CSS without leaving the browser.<ref>{{cite web|author=Mozilla |url=https://website-archive.mozilla.org/www.mozilla.org/firefox_releasenotes/en-US/firefox/10.0/releasenotes/ |title=Mozilla Firefox 10 Release Notes |publisher=Mozilla Corporation |date=January 31, 2012 |access-date=March 17, 2012}}</ref>

Firefox 10 added support for CSS 3D Transforms and for [[Spatial anti-aliasing|anti-aliasing]] in the WebGL standard for [[Hardware acceleration|hardware-accelerated]] 3D graphics. These updates mean that complex site and Web app animations will render more smoothly in Firefox, and that developers can animate 2D objects into 3D without plug-ins.<ref name="zdnet1">{{cite web|author=zebra148 |url=http://www.zdnet.com/news/firefox-10-eases-add-on-updates-but-no-android-yet/6342357 |title=Firefox 10 eases add-on updates but no Android yet |publisher=ZDNet |date=February 2, 2012 |access-date=March 17, 2012}}</ref>

=== 3D Page Inspector ===
[[File:Firefox 3D tilt.png|thumb|3D Page Inspector]]
Firefox 11, released January 2012, introduced a tiltable three-dimensional visualization of the [[Document Object Model]] (DOM), where more nested elements protrude further from the page surface.<ref>{{cite web |title=Firefox gets 3D page inspector tool |url=http://devlup.com/tech-articles/browsers/firefox-gets-3d-page-inspector-tool/3554/ |access-date=1 July 2021 |date=10 January 2012 |journal= |archive-date=July 9, 2021 |archive-url=https://web.archive.org/web/20210709183731/http://devlup.com/tech-articles/browsers/firefox-gets-3d-page-inspector-tool/3554/ |url-status=live }}</ref>  This feature was removed with version 47.<ref>{{cite web |title=3D view - Firefox Developer Tools {{!}} MDN |url=https://developer.mozilla.org/en-US/docs/Tools/3D_View |website=developer.mozilla.org |quote=From Firefox 47 onwards, 3D view is no longer available.}}</ref>

==Firefox 57 and above==

===Electrolysis and WebExtensions===
On August 21, 2015, Firefox developers announced that due to planned changes to Firefox's internal operations, including the planned implementation of a new multi-process architecture codenamed "Multiprocess Firefox" or "Electrolysis" (stylized "e10s").<ref>{{cite web|url=https://wiki.mozilla.org/Electrolysis|title=Electrolysis - MozillaWiki|website=wiki.mozilla.org|access-date=26 June 2018}}</ref> Introduced to some users in version 48, Firefox adopted a new extension architecture known as WebExtensions. WebExtensions uses HTML and JavaScript APIs and is designed to be similar to the extension API used by [[Software:Google Chrome|Google Chrome]], and run within a multi-process environment, but does not enable the same level of access to the browser. XPCOM and XUL add-ons are no longer supported effective Firefox 57.<ref name="ars-webextensions">{{cite web |title=Mozilla sets plan to dump Firefox add-ons, move to Chrome-like extensions|url=https://arstechnica.com/information-technology/2015/08/mozilla-sets-plan-to-dump-firefox-add-ons-move-to-chrome-like-extensions/|website=Ars Technica|date=21 August 2015 |access-date=August 22, 2015}}</ref><ref>{{Cite web|url=https://blog.mozilla.org/addons/2017/08/10/upcoming-changes-compatibility/|title=Upcoming Changes in Compatibility Features|website=Mozilla Add-ons Blog|date=10 August 2017 |language=en-US|access-date=2017-10-24}}</ref>

===HTTPS-only mode===
Firefox 83 introduced HTTPS-only mode, a security enhancing mode that once enabled forces all connections to websites to use HTTPS.<ref>{{cite web |title=HTTPS-Only Mode in Firefox {{!}} Firefox Help |url=https://support.mozilla.org/en-US/kb/https-only-prefs |website=support.mozilla.org}}</ref>

===Picture in Picture===
Released on December 3, 2019, Firefox 71 is the first Firefox release to include [[Engineering:Picture-in-picture|Picture-in-picture]].<ref>{{Cite web |title=Firefox 71.0, See All New Features, Updates and Fixes |url=https://www.mozilla.org/en-US/firefox/71.0/releasenotes/ |access-date=2024-01-02 |website=Mozilla |language=en}}</ref>  At first a Windows only feature, with Mac and Linux support introduced in Firefox 72,<ref>{{Cite web |title=Firefox 72.0, See All New Features, Updates and Fixes |url=https://www.mozilla.org/en-US/firefox/72.0/releasenotes/ |access-date=2024-01-02 |website=Mozilla |language=en}}</ref> picture-in-picture allows users to place a video from a webpage into a small separate window that's viewable regardless of which tab the user is in—including from outside the browser.<ref>{{Cite web |title=News from Firefox on Mobile, Private Network and Desktop {{!}} The Mozilla Blog |url=https://blog.mozilla.org/en/products/firefox/firefox-news/news-from-firefox-on-mobile-private-network-and-desktop/ |access-date=2024-01-02 |website=blog.mozilla.org |language=en-US}}</ref>

===Credit Card Auto-Fill===
Firefox 81 allowed users in the US to save, manage, and auto-fill credit card information.<ref>{{Cite web |title=Firefox 81.0, See All New Features, Updates and Fixes |url=https://www.mozilla.org/en-US/firefox/81.0/releasenotes/ |access-date=2024-01-02 |website=Mozilla |language=en}}</ref> Support for more countries have been added since the release. As of 2023, the list of supported countries is: Austria, Belgium, Canada, France, Germany, Italy, Poland, Spain, the U.K. and the U.S.<ref>{{Cite web |title=Automatically fill in credit card data on Web forms {{!}} Firefox Help |url=https://support.mozilla.org/en-US/kb/credit-card-autofill |access-date=2024-01-02 |website=support.mozilla.org}}</ref>

===Automatic Local Translation of Webpages===
Automatic translation of web content, performed entirely locally on device, was introduced to users in Firefox 118.<ref>{{Cite web |title=Firefox 118.0, See All New Features, Updates and Fixes |url=https://www.mozilla.org/en-US/firefox/118.0/releasenotes/ |access-date=2024-01-02 |website=Mozilla |language=en}}</ref> This feature is a joint effort between Mozilla, University of Edinburgh, Charles University, University of Sheffield, and the University of Tartu under the name Project Bergamot.<ref>{{Cite web |title=Mozilla releases local machine translation tools as part of Project Bergamot {{!}} The Mozilla Blog |url=https://blog.mozilla.org/en/mozilla/local-translation-add-on-project-bergamot/ |access-date=2024-01-02 |website=blog.mozilla.org |language=en-US}}</ref> Project Bergamot was funded by the European Union’s Horizon 2020 research and innovation programme.<ref>{{Cite web |title=Bergamot - a project to add and improve client-side machine translation in a web browser |url=https://browser.mt/ |access-date=2024-01-02 |website=browser.mt}}</ref>

==Tags==
===Smart Location Bar===
Firefox 3 includes a "Smart Location Bar". While most other browsers, such as Internet Explorer, will search through history for matching web sites as the user types a [[URL]] into the location bar, the Smart Location Bar will also search through bookmarks for a page with a matching URL. Additionally, Firefox's Smart Location Bar will also search through page titles, allowing the user to type in a relevant keyword, instead of a URL, to find the desired page. Firefox uses [[Frecency|frecency]] and other heuristics to predict which history and bookmark matches the user is most likely to select.

===Library===
View, organize and search through bookmarks, tags and browsing history using the new Library window. Create or restore full backups of this data whenever with a few clicks.

===Smart Bookmark Folders===
Users can quickly access their most visited bookmarks from the toolbar, or recently bookmarked and tagged pages from the bookmark menu. Smart Bookmark Folders can be created by saving a search query in the Library.

===Full page zoom===
From the View menu and via keyboard shortcuts, the new zooming feature lets users zoom in and out of entire pages, scaling the layout, text and images, or optionally only the text size. Zoom settings will be remembered for each site.

===Text selection improvements===
In addition to being able to double-click and drag to select text by words; or triple-click and drag to select text by paragraph, Ctrl (Cmd on Mac) can be held down to retain the previous selection and extend it instead of replacing it when doing another selection.<ref>{{cite web |url=http://googlesystem.blogspot.com/2008/06/cool-features-in-firefox-3.html |title=Cool Features in Firefox 3 |author=Ionut Alex. Chitu |date=2008-06-01}}</ref>

===Web-based protocol handlers===
Web applications, such as a user's favorite webmail provider, can now be used instead of desktop applications for handling mail to links from other sites. Similar support is available for other protocols (Web applications will have to first enable this by registering as handlers with Firefox).

==Add-ons and extensions==

There are six types of add-ons in Firefox: '''extensions''', '''themes''', '''[[Internationalization and localization|language packs]]''', '''[[Plug-in (computing)|plugin]]s''', '''social features''' and '''apps'''. Firefox add-ons may be obtained from the Mozilla Add-ons web site or from other sources.

===Extensions===
Firefox users can add features and change functionality in Firefox by installing extensions. Extension functionality is varied; such as those enabling mouse gestures, those that block advertisements, and those that enhance tabbed browsing.

Features that the Firefox developers believe will be used by only a small number of its users are not included in Firefox, but instead left to be implemented as extensions.<ref>{{cite web|url=http://www.mozilla.org/products/firefox/why/#simple-ui|archive-url=https://web.archive.org/web/20040210101506/http://www.mozilla.org/products/firefox/why/#simple-ui|url-status=dead|archive-date=10 February 2004|title=Reasons to switch to the Mozilla Firefox browser|date=10 February 2004|access-date=26 June 2018}}</ref> Many Mozilla Suite features, such as IRC chat ([[Software:ChatZilla|ChatZilla]]) and [[Software:Mozilla Calendar Project|calendar]] have been recreated as Firefox extensions. Extensions are also sometimes a testing ground for features that are eventually integrated to the main codebase. For example, [http://multizilla.mozdev.org MultiZilla] {{Webarchive|url=https://web.archive.org/web/20171014182623/http://multizilla.mozdev.org/ |date=2017-10-14 }} was an extension that provided tabbed browsing when Mozilla lacked that feature.

While extensions provide a high level of customizability, PC World notes the difficulty a casual user would have in finding and installing extensions as compared to their features being available by default.<ref name="pcworld">{{cite web | url = http://www.pcworld.com/article/114843-1/article.html | title = First Look at Mozilla.org's Firefox | work = PC World | access-date = 2006-09-22 | archive-date = 2009-08-25 | archive-url = https://web.archive.org/web/20090825203257/http://www.pcworld.com/article/114843-1/article.html | url-status = dead }}</ref>

Most extensions are not created or supported by Mozilla. Malicious extensions have been created.<ref>{{cite web | url = https://arstechnica.com/news.ars/post/20060726-7360.html | title = Malicious toolbars and extensions try to hijack browsers | work = ars technica | date = 27 July 2006 | access-date = 2006-09-22}}</ref> Mozilla provides a repository of extensions that have been reviewed by volunteers and are believed to not contain malware. Since extensions are mostly created by third parties, they do not necessarily go through the same level of testing as official Mozilla products, and they may have bugs or vulnerabilities.<ref>{{cite web|url=https://www.theregister.co.uk/2005/07/20/firefox_greasemonkey/|title=Firefox's Greasemonkey slippery on security|website=The Register|access-date=26 June 2018}}</ref> Like applications on [[Software:Android (operating system)|Android]] and [[Software:IOS|iOS]], Firefox extensions have permission model: for example before installing of extension user must agree that this extension can have access to all webpages, or maybe have permission to manage downloads,<ref>{{Cite web|title=permissions|url=https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/manifest.json/permissions|access-date=2020-07-16|website=MDN Web Docs|language=en}}</ref> or have no special permissions — in such way the extension can be manually activated and interact with current page. From 2019 Firefox, [[Software:Chromium (web browser)|Chromium]] based browsers ([[Software:Google Chrome|Google Chrome]], [[Software:Microsoft Edge|Edge]], [[Software:Opera (web browser)|Opera]], [[Software:Vivaldi (web browser)|Vivaldi]]) have the same format of extension: WebExtensions API,<ref>{{Cite web|title=Browser Extensions|url=https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions|access-date=2020-07-16|website=MDN Web Docs|language=en}}</ref> this is mean that web extension developed for Google Chrome can be used on Firefox (in most cases), and vice versa.

===Themes===
Firefox also supports a variety of [[Theme (computing)|themes]] for changing its appearance. Prior to the release of Firefox 57, themes are simply packages of [[Cascading Style Sheets|CSS]] and image files. From Firefox 57 onwards, themes consist solely of color modifications through the use of CSS. Many themes can be downloaded from the Mozilla Update web site.

===Language packs===
Language packs are dictionaries for spell checking of input fields.

===Plugins===
Firefox supports [[Plug-in (computing)|plugin]]s based on Netscape Plugin Application Program Interface ([[NPAPI]]), i.e. Netscape-style plugins. As a side note, Opera and Internet Explorer 3.0 to 5.0 also support NPAPI.

On June 30, 2004, the Mozilla Foundation, in partnership with [[Software:Adobe Systems|Adobe]], [[Company:Apple Inc.|Apple]], Macromedia, Opera, and [[Company:Sun Microsystems|Sun Microsystems]], [https://www.mozilla.org/press/mozilla-2004-06-30.html announced] a series of changes to web browser plugins. The then-new [[Application programming interface|API]] allowed web developers to offer [https://www.mozilla.org/projects/plugins/ richer web browsing experiences], helping to maintain innovation and standards. The then-new plugin technologies were implemented in the future versions of the Mozilla applications.

Mozilla Firefox 1.5 and later versions include the Java Embedding [[Plug-in (computing)|plugin]],<ref>{{cite web | url=http://www.mozillazine.org/talkback.html?article=7230 | title=Mozilla to include Java Embedding plugin | publisher=mozillaZine}}</ref> which allow Mac OS X users to run Java applets with the then-latest 1.4 and 5.0 versions of Java (the default Java software shipped by Apple is not compatible with any browser, except its own Safari).

===Apps===
After the releases of [[Software:Firefox OS|Firefox OS]] based on stack of web technologies, Mozilla added a feature to install mobile apps on PC using Firefox as base.

===Customizability===
[[File:Firefox--customized font colours.png|thumb|Customized font colors]]
Beyond the use of Add-ons, Firefox additional customization features.
* The position of the toolbars and interface are customizable
* User stylesheets to change the style of webpages and Firefox's user interface.
* Customizable font colours.

A number of internal configuration options are not accessible in a conventional manner through Firefox's preference dialogs, although they are exposed through its <code>about:config</code> interface.

{{Clear}}

==References==
{{Reflist|30em}}

==External links==
* [http://www.mozilla.com/en-US/firefox/features/ Firefox Features] at Mozilla.com
* [https://wiki.mozilla.org/Microsummaries Microsummaries - MozillaWiki]

{{DEFAULTSORT:Features Of Firefox}}
[[Category:Software features|Mozilla Firefox]]

{{Sourceattribution|Features of Firefox}}