Timeline of Firefox
Firefox from Mozilla’s 1998 source release and the Phoenix project to independent browser engines, developer tools, Quantum, privacy protections, and vertical tabs in 2025.
- Category
- Engineering & Technology
- Events
- 21 events 1998 – 2025
- Generated
- by gpt-6
1998: Netscape releases browser source through Mozilla
Netscape released browser-suite source code and launched the Mozilla project. The effort supplied the institutional and technical starting point for a community-developed browser family from which Firefox later emerged.
https://en.wikipedia.org/wiki/Mozilla2002: Phoenix starts a separate browser project
Mozilla developers released Phoenix, a browser that separated web browsing from the larger Mozilla application suite. The project emphasized a focused interface and became the direct predecessor of Firefox after subsequent name changes.
https://en.wikipedia.org/wiki/Firefox_version_history2003: The Mozilla Foundation becomes an independent steward
The Mozilla Foundation was established as a nonprofit organization to support the project after Netscape’s decline. It provided an independent home for browser development and Mozilla’s broader work on the web.
https://en.wikipedia.org/wiki/Mozilla_Foundation2004: Firefox 1.0 reaches the public
Mozilla released Firefox 1.0 in November with tabbed browsing, pop-up blocking, and extension support. The release gave users a widely available alternative during a period when Internet Explorer dominated desktop browsing.
https://en.wikipedia.org/wiki/Firefox2006: Firefox 2 adds session restoration and phishing checks
Firefox 2 introduced built-in session restoration, spell checking in text fields, and phishing protection. Recovering open tabs after a restart made browsing sessions less fragile while new checks addressed deceptive websites.
https://en.wikipedia.org/wiki/Firefox_version_history#Early_versions2008: Firefox 3 combines bookmarks and browsing history
Firefox 3 introduced the Places system for bookmarks and history and an address bar that searched those records. The release also updated the Gecko engine and improved memory handling.
https://en.wikipedia.org/wiki/Firefox_version_history#Early_versions2009: Firefox 3.5 adds private browsing and faster JavaScript
Firefox 3.5 introduced a private-browsing mode and the TraceMonkey JavaScript engine. Native audio and video support advanced media playback without plug-ins, while private browsing limited records retained in the local profile.
https://en.wikipedia.org/wiki/Firefox_version_history#Early_versions2011: Firefox 4 modernizes the desktop browser
Firefox 4 introduced a redesigned interface, integrated Firefox Sync, and expanded support for web graphics and acceleration. The release brought synchronization of browsing information into the main browser rather than requiring a separate add-on.
https://en.wikipedia.org/wiki/Firefox_version_history#Early_versions2011: Firefox adopts rapid releases
Firefox 5 began Mozilla’s faster release process shortly after Firefox 4. More frequent releases reduced the amount of work held for a single large launch and changed how users and extension developers received browser updates.
https://en.wikipedia.org/wiki/Firefox_version_history2012: Extended Support Releases serve managed deployments
Mozilla introduced Firefox Extended Support Release with version 10. Organizations gained a channel that kept a stable feature baseline for longer periods while receiving security updates, separating deployment needs from the rapid-release schedule.
https://en.wikipedia.org/wiki/Firefox_version_history2013: WebRTC enables communication without plug-ins
Firefox 22 enabled Web Real-Time Communication by default. Together with interoperability work with Chrome, the release let web applications use browser-provided audio, video, and data communication capabilities.
https://en.wikipedia.org/wiki/WebRTC2014: Developer Edition targets web-building workflows
Mozilla launched Firefox Developer Edition with tools and defaults oriented toward web development. The browser offered a separate environment for inspecting pages, experimenting with platform features, and testing applications.
https://en.wikipedia.org/wiki/Firefox#Channels_and_release_schedule2015: Private browsing gains tracking protection
Firefox 42 introduced Tracking Protection in private-browsing windows. Blocking requests to recognized tracking services went beyond removing local history and could also reduce the amount of third-party content loaded on a page.
https://en.wikipedia.org/wiki/Firefox2016: Multiprocess Firefox begins reaching users
Firefox 48 began rolling out the Electrolysis architecture to eligible users, separating web content from the browser interface. Process separation improved resilience and created a foundation for stronger sandboxing.
https://en.wikipedia.org/wiki/Firefox2017: WebAssembly reaches a stable browser release
Firefox 52 shipped WebAssembly support, allowing compiled programs to run through a standardized binary format in the browser. The feature expanded options for performance-sensitive web software alongside JavaScript.
https://en.wikipedia.org/wiki/WebAssembly2017: Quantum renews the browser’s core components
Firefox 57, branded Quantum, shipped a new interface and major engine improvements including the Rust-based Stylo styling system. The release also completed the move to WebExtensions, ending support for the older general-purpose extension architecture.
https://en.wikipedia.org/wiki/Firefox_version_history2019: Tracking protection becomes a default
Mozilla enabled Enhanced Tracking Protection by default for all users with Firefox 69, after first enabling it for new users earlier in the year. The browser blocked known tracking cookies and other selected tracking mechanisms without requiring an initial settings change.
https://en.wikipedia.org/wiki/Firefox2020: Firefox for Android adopts a new foundation
Mozilla released a rebuilt Firefox for Android based on GeckoView and Android Components. The browser used a revised interface and a new modular foundation, although its initial extension support was narrower than that of the previous Android browser.
https://en.wikipedia.org/wiki/Firefox_for_Android2021: Site Isolation separates more web content
Mozilla began broadly rolling out Site Isolation with Firefox 94. Separating sites into different processes strengthened boundaries around web content and reduced the amount of sensitive data that a compromised process could potentially access.
https://en.wikipedia.org/wiki/Site_isolation2022: Total Cookie Protection becomes the desktop default
Mozilla rolled out Total Cookie Protection by default for desktop users. Separating cookies by the site being visited limited the ability of third-party services to reuse the same identifier across otherwise unrelated websites.
https://en.wikipedia.org/wiki/Firefox2025: Firefox adds built-in vertical tabs
Firefox 136 introduced an updated sidebar and an option to arrange tabs vertically. Users gained a built-in alternative to the traditional horizontal tab strip, following years of related extensions and community customization.
https://en.wikipedia.org/wiki/Firefox_version_history