Mozilla Firefox or simply Firefox is a
free and open-source Free and open-source software (FOSS) is software that is both free software and open-source software where anyone is free software license, freely licensed to use, copy, study, and change the software in any way, and the source code is openly sh ...
web browser A web browser (commonly referred to as a browser) is application software Application software (app for short) is computing software designed to carry out a specific task other than one relating to the operation of the computer itself, typical ...

web browser
developed by the
Mozilla Foundation The Mozilla Foundation (stylized as moz://a) is an American non-profit organization that exists to support and collectively lead the Open-source software, open source Mozilla project. Founded in July 2003, the organization sets the policies that ...
and its subsidiary, the
Mozilla Corporation The Mozilla Corporation (stylized as moz://a) is a wholly owned subsidiary of the Mozilla Foundation that coordinates and integrates the development of Internet The Internet (Capitalization of Internet, or internet) is the global sys ...
. Firefox uses the
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rendering engine to display web pages, which implements current and anticipated web standards. In 2017, Firefox began incorporating new technology under the code name
Quantum In physics Physics is the natural science that studies matter, its Elementary particle, fundamental constituents, its Motion (physics), motion and behavior through Spacetime, space and time, and the related entities of energy and force. "P ...
to promote parallelism and a more intuitive
user interface 300px, The Reactable, an example of a tangible user interface In the industrial design field of human–computer interaction, a user interface (UI) is the space where interactions between humans and machines occur. The goal of this interaction ...
. Firefox is available for
Windows 7 Windows 7 is a major release of the developed by . It was on July 22, 2009, and became generally available on October 22, 2009. It is the successor to , released nearly three years earlier. It remained an operating system for use on personal ...
and later versions,
macOS macOS (; previously Mac OS X and later OS X) is a proprietary {{Short pages monitor As a workaround for the issue, a preloader application was created that loaded components of Firefox on startup, similar to Internet Explorer. A Windows Vista feature called SuperFetch performs a similar task of preloading Firefox if it is used often enough. Tests performed by ''PC World'' and Zimbra in 2006 indicated that Firefox 2 used less memory than Internet Explorer 7. Firefox 3 used less memory than Internet Explorer 7, Opera 9.50 Beta,
Safari A safari (; ) is an overland journey to or (in more recent times) observe , especially in or . The so-called animals of Africa – , , , , and – particularly form an important part of the safari market, both for and . Etymology The ...
3.1 Beta, and Firefox 2 in tests performed by Mozilla, CyberNet, and The Browser World. In mid-2009, BetaNews benchmarked Firefox 3.5 and declared that it performed "nearly ten times better on XP than Microsoft Internet Explorer 7".


In January 2010, Lifehacker compared the performance of Firefox 3.5, Firefox 3.6, Google Chrome 4 (stable and Dev versions), Safari 4, and Opera (10.1 stable and 10.5 pre-alpha versions). Lifehacker timed how long browsers took to start and reach a page (both right after boot-up and after running at least once already), timed how long browsers took to load nine tabs at once, tested JavaScript speeds using Mozilla's Dromaeo online suite (which implements Apple's Browser speed test#Apple benchmarks, SunSpider and Google's V8 tests) and measured memory usage using Windows 7's process manager. They concluded that Firefox 3.5 and 3.6 were the fifth- and sixth-fastest browsers, respectively, on startup, 3.5 was third- and 3.6 was sixth-fastest to load nine tabs at once, 3.5 was sixth- and 3.6 was fifth-fastest on the JavaScript tests. They also concluded that Firefox 3.6 was the most efficient with memory usage followed by Firefox 3.5. In February 2012, ''Tom's Hardware'' performance tested Chrome 17, Firefox 10, Internet Explorer 9, Opera 11.61, and Safari 5.1.2 on Windows 7. ''Tom's Hardware'' summarized their tests into four categories: Performance, Efficiency, Reliability, and Conformance. In the performance category they tested
HTML5 HTML5 is a markup language #REDIRECT Markup language In computer text processing, a markup language is a system for annotation, annotating a document in a way that is Syntax (logic), syntactically distinguishable from the text, meaning when ...

, Java (software platform), Java,
JavaScript JavaScript (), often abbreviated JS, is a programming language A programming language is a formal language In mathematics Mathematics (from Ancient Greek, Greek: ) includes the study of such topics as quantity (number theory), ma ...

, DOM, CSS 3, Adobe Flash, Flash,
Silverlight Microsoft Silverlight (or to simplify Silverlight) is a deprecated application framework designed for writing and running rich web applications, similar to Adobe Adobe (; ) is a building material made from earth and organic materials ...
, and
WebGL WebGL (Short for Web Graphics Library) is a JavaScript JavaScript (), often abbreviated JS, is a programming language A programming language is a formal language In mathematics Mathematics (from Ancient Greek, Greek: ) includ ...

(WebGL 2 is current as of version 51; and Java and Silverlight stop working as of version 52)—they also tested startup time and page load time. The performance tests showed that Firefox was either "acceptable" or "strong" in most categories, winning three categories (HTML5, HTML5 hardware acceleration, and Java) only finishing "weak" in CSS performance. In the efficiency tests, ''Tom's Hardware'' tested memory usage and management. In this category, it determined that Firefox was only "acceptable" at performing light memory usage, while it was "strong" at performing heavy memory usage. In the reliability category, Firefox performed a "strong" amount of proper page loads. In the final category, conformance, it was determined that Firefox had "strong" conformance for JavaScript and HTML5. In conclusion, ''Tom's Hardware'' determined that Firefox was the best browser for Windows 7 OS, but that it only narrowly beat Google Chrome. In June 2013, ''Tom's Hardware'' again performance tested Firefox 22, Chrome 27, Opera 12, and Internet Explorer 10. They found that Firefox slightly edged out the other browsers in their "performance" index, which examined wait times, JavaScript execution speed, HTML5/CSS3 rendering, and hardware acceleration performance. Firefox also scored the highest on the "non-performance" index, which measured memory efficiency, reliability, security, and standards conformance, finishing ahead of Chrome, the runner-up. ''Tom's Hardware'' concluded by declaring Firefox the "sound" winner of the performance benchmarks. In January 2014, a benchmark testing the memory usage of Firefox 29, Google Chrome 34, and Internet Explorer 11 indicated that Firefox used the least memory when a substantial number of tabs were open. In benchmark testing in early 2015 on a "high-end" Windows machine, comparing
Microsoft Edge Microsoft Edge is a cross-platform software, cross-platform web browser created and developed by Microsoft. It was first released for Windows 10 and Xbox One in 2015, for Android (operating system), Android and iOS in 2017, for macOS in 2019, an ...

Microsoft Edge
, Internet Explorer, Firefox, Chrome, and Opera, Firefox achieved the highest score on three of the seven tests. Four different JavaScript performance tests gave conflicting results. Firefox surpassed all other browsers on the Browser speed test, Peacekeeper benchmark but was behind the Microsoft products when tested with SunSpider. Measured with Mozilla's Kraken, it came second place to Chrome, while on Google's Browser speed test#Octane, Octane challenge it took third behind Chrome and Opera. Firefox took the lead with WebXPRT, which runs several typical HTML5 and JavaScript tasks. Firefox, Chrome, and Opera all achieved the highest possible score on the Oort Online test, measuring WebGL rendering speed (WebGL 2 is now current). In terms of HTML5 compatibility testing, Firefox was ranked in the middle of the group. A similar set of benchmark tests in 2016 showed Firefox's JavaScript performance on Kraken and the newer Browser speed test#JetStream, Jetstream tests trailing slightly behind all other tested browsers except Internet Explorer (IE), which performed relatively poorly. On Octane, Firefox came ahead of IE and Safari, but again slightly behind the rest, including Vivaldi (web browser), Vivaldi and Microsoft Edge. Edge took overall first place on the Jetstream and Octane benchmarks.

Firefox Quantum

As of the adoption of Firefox 57 and Mozilla's Gecko (software)#Quantum, Quantum project entering production browsers in November 2017, Firefox was tested to be faster than Chrome in independent JavaScript tests, and demonstrated to use less memory with many browser tabs opened. TechRadar rated it as the fastest web browser in a May 2019 report.

Usage share

Downloads have continued at an increasing rate since Firefox 1.0 was released on November 9, 2004, and Firefox had already been downloaded over one billion times. This number does not include downloads using software updates or those from third-party websites. They do not represent a user count, as one download may be installed on many machines, one person may download the software multiple times, or the software may be obtained from a third-party. In July 2010, IBM asked all employees (about 400,000) to use Firefox as their default browser. Firefox was the second-most used web browser until November 2011, when Google Chrome surpassed it. According to Mozilla, Firefox has more than 450 million users . Up to early 2020, Firefox was the second-most widely used desktop browser, and that position made it the third-most popular with 3.82% of worldwide usage share of web browsers across all platforms. According to the Firefox Public Data report by Mozilla, the active monthly count of Desktop clients has decreased from around 310 million in 2017 to 260 million in 2019. From Oct 2020, the desktop market share of Firefox started to decline in countries where it used to be the most popular. In Eritrea, it dropped from 50% in Oct 2020 to 9.32% in Sept 2021. In Cuba, it dropped from 54.36% in Sept 2020 to 38.42% in Sept 2021.

See also

* Firefox User Extension Library * History of the web browser * List of free and open-source software packages * Mozilla Prism * XULRunner


Further reading

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External links

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