This release includes a major new feature to sync your Spaces across devices using your Mozilla account! Please note that the first time this feature is enabled, it will merge both your local and cloud Spaces.

If you encounter any issues, please report them on the issues page.

Security

Various security fixes.

Fixed

Fixed live folders for GitHub issues not working with the new GitHub UI
Fixed Zen preventing Linux systems from going to sleep after a long browsing session.
Fixed arrow-key and Page Up/Down scrolling not working on some pages with embedded content from other sites.
Fixed live audio streams such as internet radio stopping when playing in the background.

Other bug fixes and improvements.

Added

Updated to Firefox 155.0 and 155.0.1

Added

By using your Mozilla account, you can now sync your Spaces, Folders, Tabs, and much more between devices! This can be enabled in Settings > Sync > Sync your Spaces across devices.

Added

The chrome UI now has a better look and feel, implementing squircles and other design elements to make it more visually appealing.

Added

A new on-boarding experience has been added to help new users get started with the browser and its features.

Added

Creating a new Space is now faster and requires less animation wait time, making the process more efficient.

Added

Containers can now be reordered in Settings, and the new order is used wherever containers are listed.

Change

Font size has been increased for the sidebar text, making it easier to read and navigate through tabs and spaces.

Change

Zen now uses firefox-portal-detection.com instead of detectportal.firefox.com to detect captive portals and check network connectivity, so network allowlists referencing the old domain need updating.

Change

PDFs smaller than the paper size can now be enlarged to fill the sheet when printing, by setting the scale above 100%.

Fixed

Improved on session store performance, lowering CPU usage spikes and disk usage when storing the session (Bug gh-14990)

Fixed duplicate separator on tab context menu (Bug gh-15031)

Fixed minimizing PiP window failing to collapse into the sidebar (Bug gh-14710)

Fixed slower access to saved passwords and unexpected Primary Password prompts caused by recent changes to password storage.

Fixed an issue where addresses were failing to autofill on some sites.

Other bug fixes and improvements.

Added

Update Firefox version to 154.0.1

If you encounter any issues, please report them on the issues page.

Security

Various security fixes.

Fixed

Improved battery life on MacOS when using vibrancy effects

Improved performance of session restore, having spikes of CPU usage every time the session is stored into disk (Bug gh-14990)

Fix multiple glance tabs when joining tabs (Bug gh-14975)

Improved rendering performance on MacOS and memory leaks when using WebRTC (Bug gh-9649)

Fixed an issue on macOS where closing a browser window could leave behind an invisible window that continued to capture mouse clicks over the area where it used to be.

Fixed an issue on Windows where an auto-hiding taskbar would not appear until the Zen window had been minimized and restored after launch.

Fixed an issue where the Windows taskbar would appear in front of a full screen Picture-in-Picture window.

Fixed PDF documents not being scaled correctly in print preview when the Fit to Page Width option is used.

Other bug fixes and improvements.

Added

Update Firefox version to 154.0

Local Zen profile backups are now available on macOS in addition to Windows and Linux, and backups can be restored across all three platforms.

Sites can now be exempted from having their cookies and site data cleared on shutdown without also being exempted from tracking protection and other cookie restrictions.

The full-page Translations feature now translates content.

The full-page Translations feature now runs language identification on all page loads, resulting in an improved experience for offering translations to users.

Performing a hard reload on a page (holding Shift while clicking the Refresh button) now also clears and updates its cached favicons.

Change

Improved performance on all systems and benchmarks by using a different memory allocator

Video seeking is now significantly faster on all operating systems, making it quicker to jump to a point in a video.

Enabled webrender compositor on Linux, improving performance and reducing power usage on Linux systems that support it.

Text selected in a PDF is now highlighted the same way as text on a web page, and the highlight color follows operating system settings such as high-contrast mode.

Known

Following recent changes to Zen's password storage, some users may experience slower performance when Zen accesses saved passwords. Users with a Primary Password enabled may also see unexpected password prompts, such as when starting Zen or opening certain content.

Fixed

Fixes issue setting keybinds with shift + digit or symbol (Bug gh-9918)

Fix closing split tab in one window changing focus of other windows (Bug gh-13761)

Fixed audio and video failing to play, or hanging when seeking, on websites that load media from a Blob URL.

Other bug fixes and improvements.

Added

Updated Firefox to 153.0.3

You can now filter draft GitHub pull requests in live folders.

Compact mode now tracks your mouse even after it leaves the window, the sidebar stays open while your cursor lingers near the window's edge and only tucks away once you move further out. This only changed for Windows and MacOS, Linux is still the same as before.

You can now move the window by dragging empty space in the top part of a webpage, with native snapping and tiling, just like dragging the titlebar. Links, buttons, and other interactive elements still work as usual.

You can now have multiple media controls in the sidebar, allowing you to control multiple media sources at once.

Improved startup performance and feeling

Fixed

Various performance fixes, energy consumption improvements, RTX Super Resolution not working, and HDR video playback not working on Windows.

NOTE: This might need a restart to take effect (Bug gh-14292)

• Fixed extra divider when urlbar has no results (Bug gh-14717)
• Fix boost applying wrong size override (Bug gh-14461)
• Fixed crashes/hangs when creating new spaces (Bug gh-14713)
• Fixed non-tab drags allowing to switch Spaces (Bug gh-14724)
• Fixed essential tab reordering not working at maximum capacity (Bug gh-14726)
• Fixed compact sidebar activation at right screen edge (Bug gh-14409)
• Other bug fixes and improvements.

Added

Updated Firefox to 153.0.1

Security

Various security fixes.

Fixed

• Fixed 'Add tab to essentials' context menu item being always disabled (Bug gh-14616)
• Fixed external links not being routed properly by Space Routing (Bug gh-14600)
• Fixed boosts size override not persisting (Bug gh-14461)
• Other bug fixes and improvements.

Added

• Updated Firefox to 153.0
• High Dynamic Range (HDR) video playback is now available on Windows - this feature needs HDR mode enabled for the display in Windows Settings - Display.
• Improved UI for container selection and management
• It is now possible to merge multiple PDFs by dragging a PDF into the PDF sidebar.
• Added support for Apple's system-wide full-screen keyboard command (Globe-F).
• Zen now verifies and displays Qualified Website Authentication Certificates (QWACs) in accordance with eIDAS regulations.
• Added improved support for videos with overlays so users can more easily access video actions from context menus.

Security

Various security fixes.

Fixed

• Fixed essentials promo UI leaving gap on pressing Esc (Bug gh-14544)
• Fixed misaligned symbolic space icons in Space options menu on Linux (Bug gh-14495)
• Fixed Spaces switching when dragging tab to another monitor (Bug gh-14511)
• Fixed tab order flipping when moving tabs between workspaces (Bug gh-14495)
• Fixed a hang that could occur after using a file picker dialog on macOS 26
• Other bug fixes and improvements.

Added

• Updated to Firefox 152.0.6

Fixed

Prevent sidebar from flickering when moving a tab (Bug gh-14131)

Full-screening while on a glance tab will now expand the glance tab to a normal tab (Bug gh-11766)

Fixed space routing tabs opening in background when it should be in foreground (Bug gh-14183)

Other minor bug fixes and improvements.

Added

Updated to Firefox 152.0.2 and 152.0.3

Added 'Edit pinned tab' context menu item to manually set a pinned tab's URL

Added 'Add Route for Domain' context menu item to quickly add a tab's domain to the Space Routing settings