Firefox is thespiritual successor ofNetscape Navigator, as theMozilla community was created byNetscape in 1998, before its acquisition byAOL.[18] Firefox was created in 2002 under the codename "Phoenix" by members of the Mozilla community who desired a standalone browser rather than theMozilla Application Suite bundle. During itsbeta phase, it proved to be popular with its testers and was praised for its speed, security, and add-ons compared toMicrosoft's then-dominantInternet Explorer 6. It was released on November 9, 2004,[19] and challengedInternet Explorer's dominance with 60 million downloads within nine months.[20] In November 2017, Firefox began incorporating new technology under the code name "Quantum" to promoteparallelism and a more intuitiveuser interface.[21]
Firefox usage share grew to a peak of 32.21% in November 2009,[22] withFirefox 3.5 overtakingInternet Explorer 7, although not all versions of Internet Explorer as a whole;[23][24] its usage then declined in competition withGoogle Chrome.[22] As of February 2025[update], according toStatCounter, it had a 6.36%usage share on traditional PCs (i.e. as a desktop browser), making it the fourth-most popular PC web browser after Google Chrome (65%),Microsoft Edge (14%), andSafari (8.65%).[25]
The project began as an experimental branch of theMozilla project byDave Hyatt,Joe Hewitt, andBlake Ross. They believed the commercial requirements ofNetscape's sponsorship and developer-drivenfeature creep compromised the utility of the Mozilla browser.[26] To combat what they saw as theMozilla Suite'ssoftware bloat, they created a standalone browser, with which they intended to replace the Mozilla Suite.[27] Version 0.1 was released on September 23, 2002.[28] On April 3, 2003, theMozilla Organization announced that it planned to change its focus from the Mozilla Suite to Firefox andThunderbird.[29]
The Firefox project has undergone several name changes.[30] The nascent browser was originally named Phoenix, after themythical bird that rose triumphantly from the ashes of its dead predecessor (in this case, from the "ashes" ofNetscape Navigator, after it was sidelined by Microsoft Internet Explorer in the "First Browser War"). Phoenix was renamed in 2003 due to a trademark claim fromPhoenix Technologies. The replacement name, Firebird, provoked an intense response from theFirebird database software project.[31][32] The Mozilla Foundation reassured them that the browser would always bear the name Mozilla Firebird to avoid confusion. After further pressure, Mozilla Firebird became Mozilla Firefox on February 9, 2004.[33] The name Firefox was said to be derived from a nickname of thered panda,[34] which became the mascot for the newly named project.[35] For the abbreviation of Firefox, Mozilla prefersFx orfx, although it is often abbreviated asFF[36] or Ff.
The Firefox project went through many versions before version 1.0 and had already gained a great deal of acclaim from numerous media outlets, such asForbes[37] andThe Wall Street Journal.[38] Among Firefox's popular features were the integratedpop-up blocker,tabbed browsing, and an extension mechanism for adding functionality. Although these features have already been available for some time in other browsers such as theMozilla Suite andOpera, Firefox was the first of these browsers to have achieved large-scale adoption so quickly.[39] Firefox attracted attention as an alternative toInternet Explorer, which had come under fire for its alleged poor program design and insecurity—detractors cite IE's lack of support for certain Web standards, use of the potentially dangerousActiveX component, and vulnerability to spyware and malware installation.[citation needed] Microsoft responded by releasingWindows XP Service Pack 2, which added several important security features to Internet Explorer 6.[40]
Version 1.0 of Firefox was released on November 9, 2004.[41] This was followed by version 1.5 in November 2005, version 2.0 in October 2006, version 3.0 in June 2008, version 3.5 in June 2009, version 3.6 in January 2010, and version 4.0 in March 2011. From version 5 onwards, the development and release model changed into a "rapid" one; by the end of 2011 the stable release was version 9, and by the end of 2012 it reached version 17.[42]
Major redesigns of itsgraphical user interface occurred on versions 4.0 (Strata) in March 2011, 29.0 (Australis) in April 2014, 57.0 (Photon) in November 2017, and 89.0 (Proton) in June 2021.
In 2016, Mozilla announced a project known asQuantum, which sought to improve Firefox's Gecko engine and other components to improve the browser's performance, modernize its architecture, and transition the browser to amulti-process model. These improvements came in the wake of decreasing market share toGoogle Chrome, as well as concerns that its performance was lapsing in comparison. Despite its improvements, these changes required existingadd-ons for Firefox to be made incompatible with newer versions, in favor of a newextension system that is designed to be similar to Chrome and other recent browsers. Firefox 57, which was released in November 2017, was the first version to contain enhancements from Quantum, and has thus been namedFirefox Quantum. A Mozilla executive stated that Quantum was the "biggest update" to the browser since version 1.0.[43][44][45] Unresponsive and crashing pages only affect other pages loaded within the same process. While Chrome uses separate processes for each loaded tab, Firefox distributes tabs over four processes by default (since Quantum), in order to balance memory consumption and performance. The process count can be adjusted, where more processes increase performance at the cost of memory, therefore suitable for computers with larger RAM capacity.[46][47]
On May 3, 2019, the expiry of an intermediate signing certificate on Mozilla servers caused Firefox to automatically disable and lock all browser extensions (add-ons).[48][49] Mozilla began the roll-out of a fix shortly thereafter, using their Mozilla Studies component.[48][49]
Support forAdobe Flash was dropped on January 6, 2021, with the release of Firefox 85.[50]
On June 1, 2021, Firefox's 'Proton' redesign was offered through its stable release channel[51] after being made available in the beta builds.[52] While users were initially allowed to revert to the old design throughabout:config, the correspondingkey-value pairs reportedly stopped working in later builds, resulting in criticism.[53] These included accessibility concerns[54][55] despite Mozilla's claim to "continue to work with the accessibility community"[56] and had not been resolved as of October 2024[update].[57]
On January 13, 2022, an issue with Firefox's HTTP/3 implementation resulted in a widespread outage for several hours.[58]
On September 26, 2023, Firefox 118.0 introduced on-device translation of web page content.[59]
Firefox provides an environment for web developers in which they can use built-in tools, such as the Error Console or theDOM Inspector, andextensions, such asFirebug and more recently there has been an integration feature withPocket. Firefox Hello was an implementation ofWebRTC, added in October 2014, which allows users of Firefox and other compatible systems to have a video call, with the extra feature of screen and file sharing by sending a link to each other. Firefox Hello was scheduled to be removed in September 2016.[71]
Former features include aFile Transfer Protocol (FTP) client for browsing file servers, the ability to block images from individual domains (until version 72),[72] a3D page inspector (versions 11 to 46), tab grouping (until version 44), and the ability to add customized extra toolbars (until version 28).[73][74][75]
Functions can be added throughadd-ons created bythird-party developers. Add-ons are primarily coded using anHTML,CSS,JavaScript, withAPI known asWebExtensions, which is designed to be compatible withGoogle Chrome andMicrosoft Edge extension systems.[76] Firefox previously supported add-ons using theXUL andXPCOM APIs, which allowed them to directly access and manipulate much of the browser's internal functionality. As compatibility was not included in the multi-process architecture, XUL add-ons have been deemedLegacy add-ons and are no longer supported on Firefox 57 "Quantum" and newer.[77][78]
Mozilla has occasionally installed extensions for users without their permission. This happened in 2017 when an extension designed to promote the showMr. Robot was silently added in an update to Firefox.[79][80]
Firefox can have themes added to it, which users can create or download from third parties to change the appearance of the browser.[81][82] Firefox also provides dark, light, and system themes.
In 2013, Firefox for Android added aguest session mode, which wiped browsing data such as tabs, cookies, and history at the end of each guest session. Guest session data was kept even when restarting the browser or device, and deleted only upon a manual exit. The feature was removed in 2019, purportedly to "streamline the experience".[83][84]
Firefox has passed theAcid2 standards-compliance test since version 3.0.[93] Mozilla had originally stated that they did not intend for Firefox to pass theAcid3 test fully because they believed that the SVG fonts part of the test had become outdated and irrelevant, due toWOFF being agreed upon as a standard by all major browser makers.[94] Because the SVG font tests were removed from the Acid3 test in September 2011, Firefox 4 and greater scored 100/100.[95][96]
Firefox also implements "Safe Browsing,"[97] aproprietary protocol[98] from Google used to exchange data related with phishing and malware protection.
Firefox supports the playback of video content protected by HTML5Encrypted Media Extensions (EME), since version 38. For security and privacy reasons, EME is implemented within a wrapper of open-source code that allows execution of aproprietaryDRM module byAdobe Systems—Adobe Primetime Content Decryption Module (CDM). CDM runs within a "sandbox" environment to limit its access to the system and provide it a randomized device ID to prevent services fromuniquely identifying the device for tracking purposes. The DRM module, once it has been downloaded, is enabled, and disabled in the same manner as otherplug-ins. Since version 47,[99] "Google's Widevine CDM on Windows and Mac OS X so streaming services likeAmazon Video can switch fromSilverlight to encrypted HTML5 video" is also supported. Mozilla justified its partnership with Adobe and Google by stating:
Firefox downloads and enables the Adobe Primetime and Google Widevine CDMs by default to give users a smooth experience on sites that require DRM. Each CDM runs in a separate container called a sandbox and you will be notified when a CDM is in use. You can also disable each CDM and opt-out of future updates
and that it is "an important step on Mozilla's roadmap to removeNPAPI plugin support."[101] Upon the introduction of EME support, builds of Firefox on Windows were also introduced that exclude support for EME.[102][103] TheFree Software Foundation andCory Doctorow condemned Mozilla's decision to support EME.[104]
Firefox has been criticized by web developers for adopting web standard and fixing bugs which are decades old. No support for view transition, gradient and CSS features lack is also criticized.[105] Firefox scores less on bothHTML5 Test and JetStream2 compared to rival browsers.[106][107]
Other issues include high battery usage, being highly resource intensive,[108] removal of tab group, use of telemetry, ads in search bar, dated download system, lack ofPWA,[109] and lack of ability to share text fragment.[110][111]
From its inception, Firefox was positioned as a security-focused browser. At the time,Internet Explorer, the dominant browser, was facing a security crisis. Multiple vulnerabilities had been found, andmalware likeDownload.Ject could be installed simply by visiting a compromised website. The situation was so bad that the US Government issued a warning against using Internet Explorer.[112] Firefox, being less integrated with the operating system, was considered a safer alternative since it was less likely to have issues that could completely compromise a computer. This led to a significant increase in Firefox's popularity during the early 2000s as a more secure alternative.[113][114] Moreover, Firefox was considered to have fewer actively exploitablesecurity vulnerabilities compared to its competitors. In 2006,The Washington Post reported that exploit code for known security vulnerabilities in Internet Explorer were available for 284 days compared to only nine days for Firefox before the problem was fixed.[115] ASymantec study around the same period showed that even though Firefox had a higher number of vulnerabilities, on average vulnerabilities were fixed faster in Firefox than in other browsers during that period.[116]
During this period, Firefox used amonolithic architecture, like most browsers at the time. This meant all browser components ran in a singleprocess with access to allsystem resources. This setup had multiple security issues. If a web page used too many resources, the entire Firefox process would hang or crash, affecting all tabs. Additionally, any exploit could easily access system resources, including user files. Between 2008 and 2012, most browsers shifted to a multiprocess architecture, isolating high-risk processes like rendering, media, GPU, and networking.[117] However, Firefox was slower to adopt this change. It wasn't until 2015 that Firefox started its Electrolysis (e10s) project to implement sandboxing across multiple components. This rewrite relied oninterprocess communication usingChromium's interprocess communication library and placed various component including the rendering component in its own sandbox.[118] Firefox released this rewrite in to beta in August 2016, noting a 10–20% increase in memory usage, which was lower than Chrome's at the time.[119] However, the rewrite caused issues with their legacy extension API, which was not designed to work cross-process and requiredshim code to function correctly.[119] After over a year in beta, the rewrite was enabled by default all users of Firefox in November 2017.[120]
In 2012, Mozilla launched a new project calledServo to write a completely new and experimental browser engine utilizingmemory safe techniques written inRust.[121] In 2018, Mozilla opted to integrate parts of the Servo project into theGecko engine in a project codenamed the Quantum project.[122] The project completely overhauled Firefox's page rendering code resulting in performance and stability gains while also improving the security of existing components.[123] Additionally, the older incompatible extension API was removed in favour of a WebExtension API that more closely resembled Google Chrome's extension system. This broke compatibility with older extensions but resulted in fewer vulnerabilities and a much more maintainable extension system.[124] While the Servo project was intended to replace more parts of the Gecko Engine,[125] this plan never came to fruition. In 2020, Mozilla laid off all developers on the Servo team transferring ownership of the project to theLinux Foundation.[126]
When Firefox initially released, it used a custom script permission policy where scripts that were signed by the page could gain access to higher privilege actions such as the ability to set a user's preferences. However, this model was not widely used and was later discontinued by Firefox. Modern day Firefox instead follows the standardsame-origin policy permission model that is followed by most modern browsers which disallows scripts from accessing any privileged data including data about other websites.[127]
It usesTLS to protect communications with web servers using strongcryptography when using theHTTPS protocol.[128] The freely availableHTTPS Everywhere add-on enforces HTTPS, even if a regular HTTPURL is entered. Firefox now supports HTTP/2.[129]
In February 2013, plans were announced for Firefox 22 to disablethird-party cookies by default. However, the introduction of the feature was then delayed so Mozilla developers could "collect and analyze data on the effect of blocking some third-party cookies." Mozilla also collaborated withStanford University's "Cookie Clearinghouse" project to develop ablacklist andwhitelist of sites that will be used in the filter.[130][131]
Version 23, released in August 2013, followed the lead of its competitors by blockingiframe, stylesheet, and script resources served from non-HTTPS servers embedded on HTTPS pages by default. Additionally,JavaScript could also no longer be disabled through Firefox's preferences, and JavaScript was automatically re-enabled for users who upgraded to 23 or higher with it disabled. The change was made due to the fact the JavaScript was being used across a majority of websites on the web and disabling JavaScript could potentially have untoward repercussions on inexperienced users who are unaware of its impact. Firefox also cited the fact that extensions likeNoScript, that can disable JavaScript in a more controlled fashion, were widely available. The following release added the ability to disable JavaScript through the developer tools for testing purposes.[132][133][134]
Beginning with Firefox 48, all extensions must be signed by Mozilla to be used in release and beta versions of Firefox. Firefox 43 blocked unsigned extensions but allowed enforcement of extension signing to be disabled. All extensions must be submitted toMozilla Add-ons and be subject to code analysis in order to be signed, although extensions do not have to be listed on the service to be signed.[135][136] On May 2, 2019, Mozilla announced that it would be strengthening the signature enforcement with methods that included the retroactive disabling of old extensions now deemed to be insecure.[137]
Since version 60 Firefox includes the option to useDNS over HTTPS (DoH), which causesDNS lookup requests to be sent encrypted over the HTTPS protocol.[138][139] To use this feature the user must set certain preferences beginning with "network.trr" (Trusted Recursive Resolver) inabout:config: if network.trr.mode is 0, DoH is disabled; 1 activates DoH in addition to unencrypted DNS; 2 causes DoH to be used before unencrypted DNS; to use only DoH, the value must be 3. By setting network.trr.uri to the URL, specialCloudflare servers will be activated. Mozilla has a privacy agreement with this server host that restricts their collection of information about incoming DNS requests.[140]
On May 21, 2019, Firefox was updated to include the ability to block scripts that used a computer'sCPU to minecryptocurrency without a user's permission, in Firefox version 67.0. The update also allowed users to block knownfingerprinting scripts that track their activity across the web, however it does not resist fingerprinting on its own.[141]
In March 2021, Firefox launched SmartBlock in version 87 to offer protection againstcross-site tracking, without breaking the websites users visit.[142] Also known as state partitioning or "total cookie protection", SmartBlock works via a feature in the browser that isolates data from each site visited by the user to ensure that cross-site scripting is very difficult if not impossible. The feature also isolates local storage, service workers and other common ways for sites to store data.[143]
In 2025, Mozilla received criticism after changes to the Firefox Terms of Use. The criticism was centered around a clause that gave Mozilla a "nonexclusive, royalty-free, worldwide license" to use any information that was uploaded or inputted into the browser. The new terms were perceived to reduce privacy, and were seen to be connected to AI, while Mozilla denied that these were the motives.[144] Criticism centered on fears that the license grant covered all data inputted, while Mozilla responded saying that the change "does NOT give us ownership of your data".[145][146] In an attempt to respond to the fallout, Mozilla said that many modified words were to ease readability, increase transparency, formalize existing implicit agreements, and describe the circumstances of a free browser, adding that the AI features are covered by a separate agreement.[146][147] Days later, Mozilla changed the wording of their privacy FAQ,[148] removing a pledge to never "sell your personal data" and revising another section denying allegations that it sold user data, saying that it gathers some information from hideable advertisements as well as chatbot metadata when interacted with, and that the legal definition of "sell" was vague in some jurisdictions.[149][150]
Firefox is a widelylocalized web browser. Mozilla uses the in-house Pontoon localization platform.[151] The first official release in November 2004 was available in 24 different languages and for 28locales.[152] In 2019, Mozilla released Project Fluent a localization system that allows translators to be more flexible with their translation than to be constrained in one-to-one translation of strings.[153][154] As of March 2025,[update] the supported versions of Firefox are available in 97 locales (88 languages).[9]
In March 2014, theWindows Store app version of Firefox was cancelled, although there is a beta release.[176]
SSE2 instruction set support is required for 49.0 or later forWindows and 53.0 or later forLinux, IA-32 support only applies tosuperscalar processors.
The x64 build for Windows (introduced with Firefox 43) was exclusive to Windows 7 and later. All previous versions of Windows have to use the IA-32 build.[177]
Firefox source code may becompiled for various operating systems; however, officially distributed binaries are provided for the following:
1 GHz or faster compatible processor[180] (ARM64 for the default release is supported on Windows but only for the Nightly release on Linux unless an ARM64 package from the Linux distribution is used[181][182])
ESR 115:Pentium 4 or newer withSSE2 (or ARM64 for Windows)
The version 42.0 release includes the firstx64 build. It requiredWindows 7 orServer 2008 R2.[185] Starting from version 49.0, Firefox for Windows requires and uses theSSE2 instruction set.
In September 2013, Mozilla released aMetro-style version of Firefox, optimized fortouchscreen use, on the "Aurora" release channel. However, on March 14, 2014, Mozilla cancelled the project because of a lack of user adoption.[186][187][188]
In March 2017, Firefox 52 ESR, the last version of the browser forWindows XP andWindows Vista, was released.[189] Support for Firefox 52 ESR ended in June 2018.[190]
Traditionally, installing the Windows version of Firefox entails visiting the Firefox website and downloading an installer package, depending on the desired localization and system architecture. In November 2021, Mozilla made Firefox available onMicrosoft Store. The Store-distributed package does not interfere with the traditional installation.[191][192]
The last version of Firefox for Windows 7 and 8 is Firefox 115 ESR, which was released in July 2023.[193] Itsend-of-life was initially planned to be in October 2024,[194] however in July 2024, a Mozilla employee announced in a comment on Reddit that the company consider extending the support beyond the initial date, the duration of that extension being yet to be defined.[citation needed] In September 2024, the extension was announced for an initial period of six months.[195] In another Reddit comment, another Mozilla employee said that despite the extension "isn't going to be free [for Mozilla]", there was enough users to justify extending the support.[196] In the release calendar page, a note states that Mozilla will re-evaluate the situation in early 2025 to see if another extension will be needed or not and statute about 115 ESR end-of-life then.[197] This extension has been renewed one more time, on February 18, 2025, for 6 additional months, which lead the end-of-life date on par with the 128 ESR branch, in September 2025.[198]
The first official release (Firefox version 1.0) supportedmacOS (then called Mac OS X) on thePowerPC architecture. Mac OS X builds for theIA-32 architecture became available via auniversal binary which debuted with Firefox 1.5.0.2 in 2006.
Starting with version 4.0, Firefox was released for the x64 architecture to which macOS had migrated.[199] Version 4.0 also dropped support for PowerPC architecture, although other projects continued development of a PowerPC version of Firefox.[200]
Firefox was originally released for Mac OS X 10.0 and higher.[201] The minimum OS then increased to Mac OS X 10.2 in Firefox 1.5 and 10.4 in Firefox 3.[202][203] Firefox 4 dropped support for Mac OS X 10.4 and PowerPC Macs, and Firefox 17 dropped support for Mac OS X 10.5 entirely.[204][205] The system requirements were left unchanged until 2016, when Firefox 49 dropped support for Mac OS X 10.6–10.8.[206][207] Mozilla ended support for OS X 10.9–10.11 in Firefox 79, with those users being supported on the Firefox 78 ESR branch until November 2021.[208][209][210] Most recently, Mozilla ended support formacOS 10.12–10.14 in Firefox 116, with those users being supported on the Firefox 115 ESR branch until late 2024. In September 2024 however, an extension was announced for the 115 ESR branch for an initial period of six months.[195] This extension has been renewed one more time, leading the end-of-life date to September 2025[198]
Firefox 133 onopenSUSE TumbleweedOpening Wikipedia main page with Mozilla Firefox 99 on Ubuntu 20.04
Since its inception, Firefox for Linux supported the 32-bit memory architecture of the IA-32 instruction set. 64-bit builds were introduced in the 4.0 release.[199] The 46.0 release replacedGTK 2.18 with 3.4 as a system requirement on Linux and other systems runningX.Org.[211] Starting with 53.0, the 32-bit builds require theSSE2 instruction set.[212]
Firefox for mobile, code-named "Fennec", was first released forMaemo in January 2010 with version 1.0[213] and forAndroid in March 2011 with version 4.0.[214] Support for Maemo was discontinued after version 7, released in September 2011.[215] Fennec had a user interface optimized for phones and tablets. It included the Awesome Bar, tabbed browsing, add-on support, a password manager, location-aware browsing, and the ability to synchronize with the user's other devices with Mozilla Firefox usingFirefox Sync.[216] At the end of its existence, it had a market share of 0.5% on Android.[217]
In August 2020, Mozilla launched a new version of its Firefox for Android app, named Firefox Daylight to the public[218] and codenamedFenix,[219] after a little over a year of testing.[220] It boasted higher speeds with its newGeckoView engine, which is described as being "the only independentweb engine browser available onAndroid". It also added Enhanced Tracking Protection 2.0, a feature that blocks many knowntrackers on the Internet.[221] It also added the ability to place the address bar on the bottom, and a new Collections feature.[218] However, it was criticized for only having nineAdd-ons at launch, and missing certain features.[222][223][224] In response, Mozilla stated that they will allow more Add-ons with time.[225]
Firefox for iOS is not listed in this table as its version numbers would be misleading. Prior to version 96[233] it used version numbers that do not correspond to any of the other Firefox versions. Those share a core component, the Gecko rendering engine, and track its version numbers, whereas the version for theiOS operating system uses the operating system's rendering engine (WebKit), rather than Mozilla's (Gecko).
Mozilla initially refused to port Firefox to iOS, due to the restrictions Apple imposed on third-party iOS browsers. Instead of releasing a full version of the Firefox browser, Mozilla released Firefox Home, a companion app for the iPhone and iPod Touch based on theFirefox Sync technology, which allowed users to access their Firefox browsing history, bookmarks, and recent tabs. It also included Firefox's "Awesomebar" location bar. Firefox Home was not a web browser, the application launched web pages in either an embedded viewer for that one page, or by opening the page in the Safari app.[234][235] Mozilla pulled Firefox Home from theApp Store in September 2012, stating it would focus its resources on other projects. The company subsequently released thesource code of Firefox Home's underlying synchronization software.[236]
In April 2013, then-Mozilla CEOGary Kovacs said that Firefox would not come to iOS if Apple required the use of theWebKit layout engine to do so. One reason given by Mozilla was that prior to iOS 8, Apple had supplied third-party browsers with an inferior version of their JavaScript engine which hobbled their performance, making it impossible to match Safari's JavaScript performance on the iOS platform.[237] Apple later opened their "Nitro" JavaScript engine to third-party browsers.[238] In 2015, Mozilla announced it was moving forward with Firefox for iOS, with a preview release made available in New Zealand in September of that year.[239][240][241] It was fully released in November later that year.[242] It is the first Firefox-branded browser not to use theGeckolayout engine as is used in Firefox fordesktop andmobile. Apple's policies require all iOS apps that browse the web to use the built-inWebKit rendering framework and WebKit JavaScript, so using Gecko is not possible.[243][244] UnlikeFirefox on Android, Firefox for iOS does not support browser add-ons.
In November 2016, Firefox released a new iOS app titledFirefox Focus, a private web browser.[245]
Firefox Reality was released for Augmented Reality and Virtual Reality headsets in September 2018.[246] It supports traditional web-browsing through 2D windows and immersive VR pages throughWeb VR. Firefox Reality is available onHTC Vive,Oculus,Google Daydream andMicrosoft Hololens headsets. In February 2022 Mozilla announced thatIgalia took over stewardship of this project under the new name of Wolvic.[247]
The Firefox port for OpenBSD is maintained by Landry Breuil since 2010. Firefox is regularly built for the current branch of the operating system, the latest versions are packaged for each release and remain frozen until the next release. In 2017, Landry began hosting packages of newer Firefox versions for OpenBSD releases from 6.0 onwards, making them available to installations without the ports system.[260]
In March 2011, Mozilla presented plans to switch to therapid release model, a faster 16-weekdevelopment cycle, similar toGoogle Chrome.Ars Technica noted that this new cycle entailed "significant technical and operational challenges" for Mozilla (notably preserving third-partyadd-on compatibility), but that it would help accelerate Firefox's adoption of new web standards, feature, and performance improvements.[266][267] This plan was implemented in April 2011.[268] The release process was split into four "channels", with major releases trickling down to the next channel every six to eight weeks. For example, the Nightly channel would feature a preliminary unstable version of Firefox 6, which would move to the experimental "Aurora" channel after preliminary testing, then to the more stable "beta" channel, before finally reaching the public release channel, with each stage taking around six weeks.[269][266][270] For corporations, Mozilla introduced an Extended Support Release (ESR) channel, with new versions released every 30 weeks (and supported for 12 more weeks after a new ESR version is released), though Mozilla warned that it would be less secure than the release channel, since security patches would only bebackported for high-impact vulnerabilities.[271][272]
In 2017, Mozilla abandoned the Aurora channel, which saw low uptake, andrebased Firefox Developer Edition onto the beta channel.[273] Mozilla usesA/B testing[274] and a staged rollout mechanism for the release channel, where updates are first presented to a small fraction of users, with Mozilla monitoring its telemetry for increased crashes or other issues before the update is made available to all users.[269] In 2020, Firefox moved to a four-week release cycle, to catch up with Chrome in support for new web features.[275][276] Chrome switched to a four-week cycle a year later.[277]
Firefoxsource code isfree software, with most of it being released under theMozilla Public License (MPL) version 2.0.[11] This license permits anyone to view, modify, or redistribute the source code. As a result, several publicly released applications have been built from it, including Firefox's predecessorNetscape,[278] the customizablePale Moon, and the privacy focusedTor Browser.[279]
In the past, Firefox was licensed solely under the MPL, then version 1.1,[280] which theFree Software Foundation criticized for beingweak copyleft, as the license permitted, in limited ways, proprietaryderivative works. Additionally, code only licensed under MPL 1.1 could not legally be linked with code under theGPL.[281][282] To address these concerns, Mozilla re-licensed most of Firefox under thetri-license scheme of MPL 1.1, GPL 2.0, orLGPL 2.1. Since the re-licensing, developers were free to choose the license under which they received most of the code, to suit their intended use: GPL or LGPL linking and derivative works when one of those licenses is chosen, or MPL use (including the possibility of proprietary derivative works) if they chose the MPL.[280] However, on January 3, 2012, Mozilla released the GPL-compatible MPL 2.0,[283] and with the release of Firefox 13 on June 5, 2012, Mozilla used it to replace the tri-licensing scheme.[284]
The name "Mozilla Firefox" is aregistered trademark of Mozilla; along with the official Firefox logo, it may only be used under certain terms and conditions. Anyone may redistribute the official binaries in unmodified form and use the Firefox name and branding for such distribution, but restrictions are placed on distributions which modify the underlying source code.[285] The name "Firefox" derives from a nickname of thered panda.[35] Mozilla celebrated Red Pandas.[286]
Mozilla has placed the Firefox logo files under open-source licenses,[287][288] but its trademark guidelines do not allow displaying altered[289] or similar logos[290] in contexts where trademark law applies.[291]
There has been some controversy over the Mozilla Foundation's intentions in stopping certain open-source distributions from using the "Firefox" trademark.[12] Open-source browsers "enable greater choice and innovation in the market rather than aiming for mass-market domination."[292] Mozilla Foundation ChairpersonMitchell Baker explained in an interview in 2007 that distributions could freely use the Firefox trademark if they did not modify source code, and that the Mozilla Foundation's only concern was with users getting a consistent experience when they used "Firefox".[293]
To allow distributions of the codewithout using the official branding, the Firefoxbuild system contains a "branding switch". This switch, often used for alphas ("Auroras") of future Firefox versions, allows the code to be compiled without the official logo and name and can allow a derivative work unencumbered by restrictions on the Firefox trademark to be produced. In the unbranded build, the trademarked logo and name are replaced with a freely distributable generic globe logo and the name of the release series from which the modified version was derived.[citation needed]
Distributing modified versions of Firefox under the "Firefox" name required explicit approval from Mozilla for the changes made to the underlying code, and required the use ofall of the official branding. For example, it was not permissible to use the name "Firefox" without also using the official logo. When theDebian project decided to stop using the official Firefox logo in 2006 (because Mozilla's copyright restrictions at the time were incompatible withDebian's guidelines), they were told by a representative of the Mozilla Foundation that this was not acceptable and was asked either to comply with the published trademark guidelines or cease using the "Firefox" name in their distribution.[294] Debian switched to branding their modified version of Firefox "Iceweasel" (but in 2016 switched back to Firefox), along with other Mozilla software.GNU IceCat is another derived version of Firefox distributed by theGNU Project, which maintains its separate branding.[295]
The Firefox icon is a trademark used to designate the official Mozilla build of the Firefox software and builds of official distribution partners.[296] For this reason, software distributors who distribute modified versions of Firefox do not use the icon.[291]
Early Firebird and Phoenix releases of Firefox were considered to have reasonable visual designs but fell short when compared to many other professional software packages. In October 2003, professional interface designer Steven Garrity authored an article covering everything he considered to be wrong with Mozilla's visual identity.[297]
Shortly afterwards, the Mozilla Foundation invited Garrity to head up the new visual identity team. The release of Firefox 0.8 in February 2004 saw the introduction of the new branding efforts. Included were new icon designs by silverorange, a group of web developers with a long-standing relationship with Mozilla. The final renderings are byJon Hicks, who had worked onCamino.[298][299] The logo was later revised and updated, fixing several flaws found when it was enlarged.[300] The animal shown in the logo is a stylized fox, although "firefox" is usually a common name for thered panda. The panda, according to Hicks, "didn't really conjure up the right imagery" and was not widely known.[299]
In June 2019, Mozilla unveiled a revised Firefox logo, which was officially implemented on version 70. The new logo is part of an effort to build a brand system around Firefox and its complementary apps and services, which are now being promoted as a suite under the Firefox brand.
Logo history
Logo of "Phoenix" and "Firebird" before being renamed as Firefox
Firefox 0.8–0.10, from February 9, 2004 to November 8, 2004
Firefox 1.0–3.0, from November 9, 2004 to June 29, 2009
Firefox 3.5–22, from June 30, 2009 to August 5, 2013
Firefox 23–56, from August 6, 2013 to November 13, 2017[301]
Firefox 57–69, from November 14, 2017 to October 21, 2019
The 2011 Aurora logo, used to represent analpha release
The 2013 Aurora logo
The 2015 Developer Edition logo
The 2017 Developer Edition logo
The 2019 Developer Edition logo
Other logos
Blue globe artwork, distributed with thesource code, and is explicitly not protected as a trademark[302]
The logo for the Firefox brand of products and services, as of July 2019. It appears as if the fox was removed, but this is not the logo for the browser itself.
Firefox was adopted rapidly, with 100 million downloads in its first year of availability.[303] This was followed by a series of aggressive marketing campaigns starting in 2004 with a series of eventsBlake Ross and Asa Dotzler called "marketing weeks".[304]
Firefox continued to heavily market itself by releasing a marketing portal dubbed "Spread Firefox" (SFX) on September 12, 2004.[305] It debuted along with the Firefox Preview Release, creating a centralized space for the discussion of various marketing techniques. The release of theirmanifesto stated that "the Mozilla project is a global community of people who believe that openness, innovation and opportunity are key to the continued health of the Internet."[292] A two-page ad in the edition of December 16 ofThe New York Times, placed by Mozilla Foundation in coordination with Spread Firefox, featured the names of the thousands of people worldwide who contributed to the Mozilla Foundation's fundraising campaign to support the launch of the Firefox 1.0 web browser.[306] SFX portal enhanced the "Get Firefox" button program, giving users "referrer points" as an incentive. The site lists the top 250 referrers. From time to time, the SFX team or SFX members launch marketing events organized at the Spread Firefox website. As a part of the Spread Firefox campaign, there was an attempt to break the world download record with the release of Firefox 3.[307] This resulted in an official certifiedGuinness world record, with over eight million downloads.[308] In February 2011, Mozilla announced that it would be retiring Spread Firefox (SFX). Three months later, in May 2011, Mozilla officially closed Spread Firefox. Mozilla wrote that "there are currently plans to create a new iteration of this website [Spread Firefox] at a later date."[309]
In celebration of the third anniversary of the founding of theMozilla Foundation, the "World Firefox Day" campaign was established on July 15, 2006,[310][311] and ran until September 15, 2006.[312] Participants registered themselves and a friend on the website for nomination to have their names displayed on the Firefox Friends Wall, a digital wall that was displayed at the headquarters of the Mozilla Foundation.
The Firefox community has also engaged in the promotion of their web browser. In 2006, some of Firefox's contributors fromOregon State University made acrop circle of the Firefox logo in anoat field nearAmity, Oregon, near the intersection of Lafayette Highway and Walnut Hill Road.[313] After Firefox reached 500 million downloads on February 21, 2008, the Firefox community celebrated by visitingFreerice to earn 500 million grains of rice.[314]
Other initiatives included Live Chat – a service Mozilla launched in 2007 that allowed users to seek technical support from volunteers.[315] The service was later retired.[316]
To promote the launch of Firefox Quantum in November 2017, Mozilla partnered withReggie Watts to produce a series of TV ads and social media content.[317]
In December 2005,Internet Week ran an article in which many readers reported high memory usage in Firefox 1.5.[318] Mozilla developers said that the higher memory use of Firefox 1.5 was at least partially due to the new fast backwards-and-forwards (FastBack) feature.[319] Other known causes of memory problems were malfunctioning extensions such asGoogle Toolbar and some older versions ofAdBlock,[320] or plug-ins, such as older versions of Adobe Acrobat Reader.[321] WhenPC Magazine in 2006 compared memory usage of Firefox 2,Opera 9, andInternet Explorer 7, they found that Firefox used approximately as much memory as each of the other two browsers.[322]
In 2006,Softpedia noted that Firefox 1.5 took longer to start up than other browsers,[323] which was confirmed by furtherspeed tests.[324]
Internet Explorer 6 launched more swiftly than Firefox 1.5 onWindows XP since many of its components were built into the OS and loaded during system startup. As a workaround for the issue, a preloader application was created that loaded components of Firefox on startup, similar to Internet Explorer.[325] AWindows Vista feature calledSuperFetch performs a similar task of preloading Firefox if it is used often enough.[citation needed]
Tests performed byPC World and Zimbra in 2006 indicated that Firefox 2 used less memory than Internet Explorer 7.[326][327] Firefox 3 used less memory than Internet Explorer 7, Opera 9.50 Beta,Safari 3.1 Beta, and Firefox 2 in tests performed by Mozilla, CyberNet, and The Browser World.[328][329][330] In mid-2009, BetaNews benchmarked Firefox 3.5 and declared that it performed "nearly ten times better on XP than Microsoft Internet Explorer 7".[331]
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'sSunSpider 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.[332]
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 testedHTML5,Java,JavaScript,DOM,CSS 3,Flash,Silverlight, andWebGL (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, HTML5hardware acceleration, and Java) only finishing "weak" in CSS performance. In the efficiency tests,Tom's Hardware tested memory usage and management. With 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. For the final category, conformance, it was determined that Firefox had "strong" conformance for JavaScript and HTML5. So in conclusion,Tom's Hardware determined that Firefox was the best browser for Windows 7 OS, but that it only narrowly beat Google Chrome.[333]
In June 2013,Tom's Hardware again performance tested Firefox 22, Chrome 27, Opera 12, andInternet 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.[334]
In January 2014, a benchmark testing the memory usage of Firefox 29, Google Chrome 34, andInternet Explorer 11 indicated that Firefox used the least memory when a substantial number of tabs were open.[335]
In benchmark testing in early 2015 on a "high-end" Windows machine, comparingMicrosoft Edge [Legacy], 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 thePeacekeeper 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'sOctane 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.[336]
A similar set of benchmark tests in 2016 showed Firefox's JavaScript performance on Kraken and the newerJetstream 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, includingVivaldi and Microsoft Edge [Legacy]. Edge [Legacy] took overall first place on the Jetstream and Octane benchmarks.[337]
As of the adoption of Firefox 57 and Mozilla'sQuantum 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.[338][339]TechRadar rated it as the fastest web browser in a May 2019 report.[340]
Downloads have continued at an increasing rate since Firefox 1.0 was released, and as of 31 July 2009[update] Firefox had already been downloaded over one billion times.[341] This number does not include downloads using software updates or those from third-party websites.[342] 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.[citation needed]
In July 2010,IBM asked all employees (about 400,000) to use Firefox as their default browser.[343]
Firefox was the second-most used web browser until November 2011, when Google Chrome surpassed it.[344] According to Mozilla, Firefox had more than 450 million users as of October 2012[update].[345][346]
In October 2024, Firefox was the fourth-most widely used desktop browser, and it was the fourth-most popular with 2.95% of worldwideusage share of web browsers across all platforms.[347]
Desktop web browser market share according toStatCounter for February 2025[348]
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 200 million in 2023.[349]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.[350][351]
The UK[352] and US[353] governments both follow the 2% rule. This states that only browsers with more than 2% market share among visitors of their websites will be supported. There are concerns that support for Firefox will be dropped because as of December 29, 2023, the browser market share among US government website visitors is 2.2%.[354]
^"Red panda".BBC Nature. Archived fromthe original on January 11, 2014. RetrievedAugust 20, 2014.
^abGarrity, Steven; Markham, Gervase; Goodger, Ben; Decrem, Bart; et al."Firefox name FAQ".mozilla.org. Archived fromthe original on February 28, 2012. RetrievedMarch 13, 2012.
^"Firefox 1.5 Release Notes".mozilla.org archive. November 29, 2005.Archived from the original on November 18, 2014. RetrievedNovember 17, 2014.
^"Location-Aware Browsing". Mozilla Foundation.Archived from the original on February 15, 2023. RetrievedJuly 5, 2009. (section "What information is being sent, and to whom? (...)")
^"Firefox 72.0, See All New Features, Updates and Fixes".Mozilla. January 7, 2020.Archived from the original on January 7, 2020. RetrievedOctober 20, 2021.Support for blocking images from individual domains has been removed from Firefox, because of low usage and poor user experience.
^"Phishing and Malware Protection". Mozilla Corp. How does Phishing and Malware Protection work in Firefox?.Archived from the original on August 13, 2021. RetrievedNovember 29, 2009.
^Theo - t3․gg (February 11, 2025).Firefox is hard to love. RetrievedFebruary 18, 2025 – via YouTube.{{cite AV media}}: CS1 maint: numeric names: authors list (link)
^Mossberg, Walter S. (September 16, 2004)."How to Protect Yourself From Vandals, Viruses If You Use Windows".The Wall Street Journal. Archived fromthe original on February 21, 2007. RetrievedOctober 17, 2006.I suggest dumping Microsoft's Internet Explorer Web browser, which has a history of security breaches. I recommend instead Mozilla Firefox, which is free at mozilla.org. It's not only more secure but also more modern and advanced, with tabbed browsing, which allows multiple pages to be open on one screen, and a better pop-up ad blocker than the belated one Microsoft recently added to IE.
^abCallahan, Dan (April 11, 2016)."The "Why" of Electrolysis".Mozilla Add-ons Community Blog.Archived from the original on June 6, 2024. RetrievedJune 6, 2024.
^Nightingale, Johnathan (March 14, 2014)."Update on Metro".Firefox Future Releases Blog.Archived from the original on April 24, 2017. RetrievedMarch 14, 2014.
^"App Store Review Guidelines".developer.apple.com. September 12, 2019.Archived from the original on March 4, 2020. RetrievedNovember 11, 2020.2.5.6 Apps that browse the web must use the appropriate WebKit framework
^"Stop Logo Cruelty". Mozilla Corp. Archived fromthe original on May 22, 2010. RetrievedMarch 7, 2009."Don't Create new elements that look enough like the Firefox logo so as to cause confusion."
^Brinkmann, Martin (January 2, 2008)."Firefox Live Chat Support".gHacks Technology News.Archived from the original on May 2, 2014. RetrievedMay 2, 2014.
^"Mozilla Blog". The Mozilla Blog. November 14, 2017.Archived from the original on July 23, 2018. RetrievedJuly 23, 2018.
.png)
![Firefox 23–56, from August 6, 2013 to November 13, 2017[301]](/mt/?noimg=&dark=on&url=https%3a%2f%2fen.wikipedia.org%2fwiki%2fFile%3aMozilla_Firefox_logo_2013.svg){kind=logo}
![Blue globe artwork, distributed with the source code, and is explicitly not protected as a trademark[302]](/mt/?noimg=&dark=on&url=https%3a%2f%2fen.wikipedia.org%2fwiki%2fFile%3aDeer_park_globe.svg)
