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Changelog

Latest Waterfox release notes, updates, and improvements.

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6.6.9 - Security and stability improvements

Desktop
February 24, 2026 View full notes

Security fixes, certificate reliability improvements, and JPEG-XL performance gains.

What's included:

  • Fixed multiple security vulnerabilities as described in Mozilla Foundation Security Advisory 2026-15.
  • Fixed 3 CVEs in the JPEG-XL image decoder.
  • Fixed an issue that could cause 'Unknown Issuer' certificate errors on certain sites, most commonly on Linux.
  • Small performance improvement in JPEG-XL image decoding.
  • Ogg Theora support can be experimentally re-enabled.
  • Printer driver isolation on Windows for improved stability.

1.2.0 - A stronger foundation

Android
February 19, 2026 View full notes

Less deps, and expanded theme customisation

What's included:

  • Updated base from Gecko 140 to 148, bringing in newer browser improvements and fixes.
  • Enabled GeckoView Lite which trims out extra built in components the app doesn't need, which keeps the app smaller and reduces background overhead.
  • Implemented a dummy version of Mozilla's Glean telemetry SDK and fully removed the Adjust SDK.
  • Improved themes customisation is now under Settings > Customize, with separate light and dark colors and an option to match your device theme automatically.

1.1.9 - Security fixes

Android
January 13, 2026 View full notes

Fixes for various security issues

What's included:

  • (MFSA 2026-03) Security Vulnerabilities fixed in Firefox ESR 140.7
  • (MFSA 2025-94) Security Vulnerabilities fixed in Firefox ESR 140.6

6.6.8 - Tab unloading & passkeys

Desktop
January 12, 2026 View full notes

Manual tab unloading with improved unloaded tab previews, macOS passkeys, Windows redist bundling, and assorted import/UI fixes.

What's included:

  • Manually unload tabs from the tab context menu, with improved unloaded tab previews.
  • Web Authentication (passkeys) support on macOS.
  • Windows builds now bundle the required Visual Studio redistributables for easier fresh installs.

6.6.7 - Import & Linux video fixes

Desktop
December 19, 2025 View full notes

Fixes Windows Firefox import issues, resolves Linux HDR playback problems, and ships a verified Flathub Flatpak.

What's included:

  • Fixed issue importing Firefox data on Windows (Settings > Import browser data).
  • Fixed an issue on Linux where HDR would be broken on YouTube videos.
  • Linux has now been verified on Flathub, so you can trust the provenance of it.

1.1.8 - Security fixes

Android
December 16, 2025 View full notes

Fixes for various security issues

What's included:

  • (MFSA 2025-94) Security Vulnerabilities fixed in Firefox ESR 140.6

6.6.6 - Privacy hardening

Desktop
December 9, 2025 View full notes

Explicitly disables some settings and fixes some feature implementations.

What's included:

  • Explicitly disables network-based region and geo-IP lookups, fixing region to a non-dynamic value.
  • Turns off the local ML/AI runtime, AI link previews and related Labs plumbing so they can’t re-enable themselves from old Firefox profiles.
  • Translations remain available, and fixes Private Tab search and status bar Bookmarks widget behaviour."

6.6.5.1 - Startpage default search and Tree Vertical Tabs fix

Desktop
November 25, 2025 View full notes

Small 6.6.5.1 patch that switches the default search back to Startpage and fixes Tree Vertical Tabs behaviour and options visibility.

What's included:

  • Switches the default search engine back to Startpage, without affecting users who have already changed their default.
  • Fixes Tree Vertical Tabs continuing to run in the background when disabled, so turning it off actually unloads the feature and can reduce memory usage.
  • Fixes Tree Vertical Tabs options appearing at the bottom of Preferences/Settings → General on first load so they now only appear under the dedicated Tree Vertical Tabs category.

1.1.7 - Startup crash fixes

Android
November 22, 2025 View full notes

Android 1.1.7 fixes crashes and ANR issues on startup for certain devices.

What's included:

  • Fixes crashes and ANR issues during startup on certain Android devices.
  • Improves overall stability at application launch.

1.1.6 - Search defaults and security update

Android
November 20, 2025 View full notes

Updates search defaults on Android and brings in the latest security fixes from Mozilla Foundation Security Advisory 2025-88.

What's included:

  • Changes the default search engine back to Startpage for users who have not customised their default.
  • Includes all security fixes from Mozilla Foundation Security Advisory 2025-88.

6.6.5 - Ukrainian locale and quick URL copy

Desktop
November 10, 2025 View full notes

Adds a Ukrainian UI locale, a quick shortcut to copy the current tab URL, and the latest security fixes for Waterfox 6.6.5.

What's included:

  • Adds Ukrainian as a UI language.
  • Introduces a keyboard shortcut to quickly copy the current tab URL on macOS (Command+Shift+U) and Windows/Linux (Ctrl+Shift+U).
  • Includes the latest security advisories from MFSA 2025-89.

1.1.5 - Ecosia partnership and search fixes

Android
October 14, 2025 View full notes

Android release that renews the Ecosia search partnership, fixes Mojeek search queries, and pulls in the latest security and stability fixes.

What's included:

  • Renews the Ecosia search partnership on Android with a focus on climate-positive, privacy-friendly search.
  • Keeps existing non-Ecosia default search choices unchanged while offering Ecosia as an improved default.
  • Fixes malformed search queries when using Mojeek.
  • Updates to GeckoView ESR 140.4 and Android Components 140.4 for upstream security and stability fixes.

6.6.4 - Ecosia partnership, Waterfox Private Search, and search fixes

Desktop
October 9, 2025 View full notes

Waterfox 6.6.4 restores canonical app naming on Linux, renews the Ecosia partnership, adds Waterfox Private Search, adjusts tab grouping defaults, and fixes several search provider and security issues.

What's included:

  • Renews the Ecosia partnership and makes Ecosia the default search engine again.
  • Introduces Waterfox Private Search as an optional subscription-based, ad-free search provider.
  • Fixes Mojeek search queries and restores Google search autocomplete when set as default.
  • Applies all security advisories from Mozilla MFSA 2025-83.
  • Restores the Linux app name and window class to 'waterfox' for better desktop integration.
  • Disables automatic tab grouping by default due to a group-merging issue, with a preference to re-enable it.

6.6.3 - Theming polish and tab group refinements

Desktop
September 11, 2025 View full notes

Polish-focused 6.6.3 update that fixes theme style leakage, improves contrast, refines tab group behavior, and updates emoji support.

What's included:

  • Fixes a long-standing issue where Waterfox interface styles could bleed into website content.
  • Improves theme colouring to avoid contrast issues and enables the active tab context line by default.
  • Refines tab group behavior at startup and when collapsing the only group, keeping layout stable.
  • Updates emoji rendering to Emoji 16.0.1 on platforms without native support.

1.1.4 - OLED black theme

Android
September 4, 2025 View full notes

Android 1.1.4 adds a black theme optimized for OLED devices and updates core libraries for the latest security and performance fixes.

What's included:

  • Adds a Black theme specifically designed for OLED displays.
  • Updates to the latest development libraries for improved security and performance.

6.6.2 - Theme refinements, Windows Mica/Acrylic, and tab group improvements

Desktop
August 29, 2025 View full notes

Waterfox 6.6.2 polishes the theme, refines vertical tabs and Windows translucency, and improves tab grouping behavior while restoring recent history and top sites in the address bar.

What's included:

  • Refines the default Waterfox UI theme, including restoring tab shapes and improving contrast between active/inactive tabs and the navigation bar.
  • Adds Windows 11 Mica-style translucency with optional stronger Acrylic effects via about:config.
  • Improves tab grouping behavior so new tabs stay in the correct group, collapsing the only group works intuitively, and the cancel auto-grouping shortcut behaves reliably.
  • Makes auto-grouping more resilient by cleaning up timers and listeners and handling edge cases across windows.
  • Restores recent history and top sites in the address bar and fixes middle-click paste behavior on Linux.
  • Begins addressing a long-standing issue where some users saw an empty or hidden profile after updating.

6.6.1 - WebGPU enablement and private tab improvements

Desktop
August 21, 2025 View full notes

Patch release that enables WebGPU on stable builds, fixes several Linux and Windows UI issues, and adds new privacy and control options for Private Tabs.

What's included:

  • Enables WebGPU on release channel builds by removing code that previously blocked it.
  • Restores Unity global menu support on Linux and fixes issues with the Restart command and its alignment on Linux and Windows.
  • Fixes the missing Install update option in about:addons when automatic updates are disabled.
  • Disables captive portal detection so the operating system handles it, removing an extra network request to Mozilla.
  • Reorganizes Waterfox language strings and restores missing Tree Vertical Tabs labels.
  • Adds a preference to control the New Private Tab button and tightens privacy for Private Tabs by disabling suggestions and not saving search terms.

6.6.0 - Major ESR 140 upgrade with vertical tabs, tab groups, and new tab experience

Desktop
August 19, 2025 View full notes

Waterfox 6.6.0 upgrades the underlying platform from ESR 128 to 140 and introduces first-party vertical tabs, private tabs, tab grouping, new tab wallpapers, expanded media and hardware acceleration, and privacy-friendly defaults.

What's included:

  • Upgrades the underlying platform from ESR 128 to ESR 140, rolling up twelve months of upstream changes.
  • Adds first-party vertical tabs with optional tree-style layout and a quick New Private Tab button.
  • Introduces automatic tab grouping, customizable placement, and a redesigned new tab page with wallpapers, search bar, and optional weather.
  • Enables Firefox profile import for bookmarks, history, cookies, form data, and passwords.
  • Turns on WebGPU, Web Share API, VP8/VP9 hardware acceleration for WebRTC, improved MathML rendering, and other modern platform features.
  • Refines the UI with layout and theming options, status bar, compact density, and platform-specific polish on Windows and macOS.
  • Tightens privacy defaults by reducing promos, speculative connections, remote config fetches, and bundled A/B testing code.

1.1.3 - JPEG-XL animations and theme stability

Android
August 15, 2025 View full notes

Adds support for animated and alpha-transparent JPEG-XL images and fixes crashes when using custom themes on Android.

What's included:

  • Adds support for JPEG-XL images with animations and alpha transparency on Android.
  • Fixes experimental crashes when a custom theme is selected due to missing colour definitions.

6.6.0 Beta 6 - Theming and stability fixes before 6.6.0 final

Desktop
August 14, 2025 View full notes

Final 6.6.0 beta that polishes theming and fixes crashes caused by optimization flags on some systems.

What's included:

  • Fixes various small theming issues introduced in earlier 6.6 betas.
  • Resolves crashes on certain systems caused by aggressive optimization flags.

1.1.2 - Experimental themes, wallpapers, and x86_64 support

Android
August 10, 2025 View full notes

Adds experimental theme and wallpaper support on Android and reintroduces support for x86_64 Android devices.

What's included:

  • Adds experimental theme support so users can try alternate UI themes.
  • Introduces experimental custom wallpapers to personalize the app background.
  • Reintroduces support for x86_64 Android devices.

6.6.0 Beta 5 - Private tab button and privacy fixes

Desktop
August 7, 2025 View full notes

Fifth 6.6.0 beta adding an easily accessible New Private Tab button and fixing private tab history, translation model downloads, password autofill, and the screenshot tool.

What's included:

  • Adds a clearly visible New Private Tab button next to the New Tab button.
  • Ensures Private Tabs no longer retain browsing history.
  • Fixes translation model downloads so language packs are no longer blocked.
  • Restores password autofill behavior.
  • Returns the screenshot tool to the context menu.

6.6.0 Beta 4 - Onboarding and new tab personalization

Desktop
August 6, 2025 View full notes

Fourth 6.6.0 beta reintroducing the about:welcome setup experience and adds search, weather, and wallpaper customization to the new tab page.

What's included:

  • Brings back the about:welcome onboarding flow for new or reset profiles.
  • Adds a toggle to show or hide a search bar on the new tab page.
  • Adds an optional weather widget for your location on the new tab page (opt-in, requires sending your IP to Mozilla).
  • Lets you set custom new tab wallpapers using your own image, predefined colors, or a custom color.

6.5.11 - Final ESR 128 security update

Desktop
July 28, 2025 View full notes

Final 6.5.x release on ESR 128 delivering the latest security fixes before the move to ESR 140 in Waterfox 6.6.

What's included:

  • Includes the latest security fixes (MFSA 2025-58).
  • Marks the final Waterfox release based on ESR 128 before moving to ESR 140 in the 6.6 release series.

1.1.1 - DuckDuckGo fix and menu improvements

Android
July 28, 2025 View full notes

Android release that fixes the DuckDuckGo default search engine bug and adds a Quit button plus a menu redesign toggle.

What's included:

  • Fixes an issue where DuckDuckGo could not be set correctly as the default search engine.
  • Adds a Quit button to the main menu for easier app exit.
  • Introduces a toggle to switch between the new menu design and the classic layout.

6.6.0 Beta 3 - macOS auto-update fix and logo, privacy, and classic extensions tweaks

Desktop
July 24, 2025 View full notes

Third 6.6.0 beta that fixes a macOS auto-update bug, refreshes the liquid glass logo, tightens speculative connections and remote config behavior, and restores classic extension compatibility.

What's included:

  • Fixes a macOS auto-update bug in earlier beta builds by requiring a one-time manual reinstall and cache cleanup.
  • Updates the Waterfox logo and dock icon on macOS 26 and standardizes icons across platforms.
  • Disables speculative connections when typing in the address bar and uses bundled offline copies of remote settings instead of contacting Mozilla.
  • Removes packaged A/B testing code that was already disabled.
  • Fixes duplicate tab creation when opening a duplicate and restores compatibility with classic-style extensions such as TabMixPlus.

1.1.0 - ESR-based rebuild of Waterfox for Android

Android
July 18, 2025 View full notes

Major rebuild of Waterfox for Android on the ESR codebase with everything compiled from source for better stability, performance, and privacy-friendly defaults.

What's included:

  • Rebuilds Waterfox for Android on the ESR codebase with Android Components, Gecko, and SpiderMonkey compiled from scratch.
  • Removes telemetry, sponsored content, experimentation frameworks, and tracking services in favour of strict privacy defaults.
  • Adds advanced privacy features such as enhanced DNS over HTTPS with Ultra Protection (Oblivious HTTP) and full about:config access.
  • Greatly expands add-on support: browse and install from the full Mozilla Add-ons store, use Android-only views, custom AMO collections, and install .xpi files.
  • Updates search and navigation with privacy-focused engines, Waterfox-specific top sites, and JPEG-XL support.
  • Simplifies the app by removing unnecessary integrations and preparing new distribution channels like GitHub APKs and alternative app stores.

6.6.0 Beta 2 - Tree vertical tabs and automatic tab grouping

Desktop
July 8, 2025 View full notes

Second 6.6.0 beta focusing on tree-style vertical tabs, automatic tab grouping, and Firefox profile import on the ESR 140 platform.

What's included:

  • Introduces tree-style vertical tabs in the vertical tab sidebar.
  • Adds automatic tab grouping with configurable placement, delay, and a cancel shortcut.
  • Allows importing bookmarks, history, cookies, form history, and passwords directly from a Firefox profile.
  • Exposes fine-grained control over auto-grouping behavior via about:config preferences.

6.5.10 - Security fixes and Startpage default search

Desktop
June 24, 2025 View full notes

Patch release that includes the latest security fixes and temporarily switches the default search engine to Startpage while Bing syndication is being retired.

What's included:

  • Includes the latest security fixes from Mozilla's MFSA 2025-53 advisory.
  • Temporarily switches the default search engine to Startpage while Bing search syndication and APIs are discontinued.
  • Highlights the availability of Waterfox 6.6.0 Beta 1 for testing on ESR 140.

6.6.0 Beta 1 - ESR 140 beta: platform upgrade and modern web features

Desktop
June 24, 2025 View full notes

First 6.6.0 beta upgrading Waterfox to the ESR 140 platform with WebGPU, modern CSS/DOM/SVG features, improved media and WebRTC, and UI/network/privacy refinements.

What's included:

  • Upgrades the underlying platform from version 128.0 to 140.0 for beta testing.
  • Enables experimental web platform features including CSS Masonry layout, new CSS and SVG capabilities, and modern DOM APIs such as CloseWatcher and screen orientation lock.
  • Improves media and graphics with WebGPU, VP8/VP9 hardware acceleration for WebRTC, MathML updates, and enhanced autoplay controls.
  • Refines UI defaults such as smooth scrolling, updated Proton colors, and layout and bookmark tweaks.
  • Introduces network and cookie handling improvements like CHIPS, SameSite enhancements, and HTTP/3-related optimizations.
  • Reduces promotions and tightens extension and privacy behavior in line with upstream platform changes.

6.5.8 - Security update and media crash hotfix

Desktop
May 22, 2025 View full notes

Security-focused 6.5.8 release with the latest upstream fixes, a short-lived media crash issue resolved in 6.5.9, and continued promotion of the Waterfox Private Search open beta.

What's included:

  • Includes the latest security fixes from Mozilla advisories MFSA 2025-37 and MFSA 2025-43.
  • Documents a temporary crash affecting certain media-heavy sites, resolved in follow-up release 6.5.9.
  • Continues the open beta promotion of Waterfox Private Search as a more private, ad-light search option.

6.5.9 - Security fixes and media crash patch

Desktop
May 22, 2025 View full notes

Patch release that addresses media playback crashes and includes the latest upstream security fixes, while continuing the Waterfox Private Search open beta.

What's included:

  • Includes the latest security fixes from MFSA 2025-37 and MFSA 2025-44.
  • Fixes crashes when playing certain media files.
  • Highlights the ongoing open beta for Waterfox Private Search.

6.5.7 - Vertical tabs improvements and security fixes

Desktop
April 29, 2025 View full notes

Patch release focusing on vertical tabs polish, stability, and the latest security updates, plus an open beta of Waterfox Private Search.

What's included:

  • Includes the latest security fixes (MFSA 2025-29).
  • Improves vertical tabs favicon handling, bookmarks sidebar and library integration, popup menus, tab previews, private window stability, and drag-and-drop behavior.
  • Announces the open beta of Waterfox Private Search, a privacy-focused meta-search engine.

6.5.6 - JPEG-XL security fixes and WASM sandbox restoration

Desktop
March 25, 2025 View full notes

Patch release that updates JPEG-XL to address security issues, restores WASM sandboxed libraries, and includes the latest security fixes.

What's included:

  • Updated the JPEG-XL library to resolve reported security issues.
  • Re-enabled WASM sandboxed libraries after fixing underlying build issues.
  • Includes the latest upstream security fixes (MFSA 2025-17).

6.5.5 - Restart button and status bar fixes

Desktop
March 5, 2025 View full notes

Patch release that restores the Restart button on Linux and Windows, cleans up the status bar text, and includes the latest security updates.

What's included:

  • Includes the latest security fixes from Mozilla (MFSA 2025-13).
  • Restores the Restart button on Linux and Windows.
  • Removes the unexpected `(NULL)` label from the status bar text on Linux and Windows.

6.5.4 - Security update for 6.5.4

Desktop
February 4, 2025 View full notes

This patch release delivers the latest upstream security fixes for Waterfox 6.5.4 and documents the remaining known issue with the Restart button on Linux and Windows.

What's included:

  • Includes the latest security fixes from Mozilla's MFSA 2025-09 advisory.
  • Restart button remains missing on Linux and Windows (known issue).

6.5.3 - Stability and theming fixes

Desktop
January 7, 2025 View full notes

Maintenance release with theming polish, configuration clean-up, and the latest security updates.

What's included:

  • Polished various theming issues.
  • Updated base configuration defaults and removed unused values.
  • Includes the latest security fixes (MFSA 2025-02).
  • Restart button remains missing on Linux and Windows.
  • Some users may still experience session restore issues (Bug 1901899).

6.5.2 - Theming, vertical tabs, and security fixes

Desktop
November 26, 2024 View full notes

Patch release focusing on theming improvements, vertical tab stability, and the latest security updates.

What's included:

  • Fixes various theming issues across the browser UI.
  • Resolves multiple problems with vertical tabs.
  • Includes the latest upstream security fixes (MFSA 2024-64).

6.5.1 - JPEG-XL stability and Look & Feel fixes

Desktop
November 9, 2024 View full notes

Bugfix release that updates the JPEG-XL library to prevent crashes and restores missing Look & Feel strings.

What's included:

  • Updated the JPEG-XL library to the latest version to stop crashes on sites serving .jxl images.
  • Restored missing strings on the Look & Feel preferences page so theme settings can be changed again.
  • Known issues remain: missing Restart button on Linux/Windows, status bar colour mismatches, and occasional session restore problems.

6.5.0 - ESR 128 stable and architecture overhaul

Desktop
October 30, 2024 View full notes

First stable Waterfox 6.5 release on the ESR 128 branch with updated system requirements, performance tuning, and classic tools like the legacy password and config managers.

What's included:

  • First stable release of the ESR 128 branch (6.5.x) with updated versioning and dropping the 'G' prefix
  • Raised minimum system requirements to match modern Windows 10-era hardware (SSE3-class CPUs)
  • Retuned CPU code generation for Skylake-class and newer processors for better performance
  • Added a Table of Contents to the Preferences page for easier navigation
  • Reintroduced the classic password manager and configuration manager

6.5.0 Beta 3 - CPU compatibility, security patches, and DRM fixes

Desktop
October 17, 2024 View full notes

Third 6.5.0 beta improving compatibility with older CPUs, applying security patches, and fixing DRM playback on macOS.

What's included:

  • Improves compatibility with older CPUs.
  • Includes additional security patches for this beta.
  • Fixes DRM playback on macOS.

6.5.0 Beta 2 - Fixes for vertical tabs and default browser issues

Desktop
October 2, 2024 View full notes

Second 6.5.0 beta focusing on fixing the initial round of vertical tab bugs and default browser handling on Windows.

What's included:

  • Fixes setting Waterfox as the default browser on Windows.
  • Corrects vertical tabs autohide behavior in F11 fullscreen.
  • Resolves errors and missing functionality in the vertical tabs options page and sidebar menu.
  • Restores tab preview and F1 toggling behavior for Waterfox vertical tabs.
  • Fixes toolbar customisation issues that could remove the vertical tabs button.

6.5.0 Beta 1 - ESR 128 beta and architecture overhaul

Desktop
September 6, 2024 View full notes

First Waterfox 6.5.0 beta on the ESR 128 branch with updated system requirements, performance tuning, and classic tools returning.

What's included:

  • First beta release on the ESR 128 branch (6.5.x) and dropping the 'G' prefix from version numbers.
  • Raises minimum system requirements to match modern Windows 10-era hardware (SSE3-class CPUs).
  • Retunes CPU code generation for Skylake-class and newer processors for improved performance.
  • Adds a Table of Contents to the Preferences page for easier navigation.
  • Allows setting any URL as the new tab page via the browser.newtab.url preference in about:config.
  • Reintroduces the classic password manager implementation.