# Zen Browser changelog > Zen Browser release notes. - Vendor: Zen Browser - Category: Browsers - License: MPL-2.0 - Language: C++ - Official site: https://zen-browser.app/ - Tracked by: What's New (https://whatsnew.fyi/product/zen-browser) - Harvested from: GitHub (zen-browser/desktop) - Entries below: 23 (newest first) What's New is an index, not a publisher: every entry below links to the vendor's own release notes, which are the authoritative source. Entries are labelled where they are hand-curated sample data, pre-releases, or drawn from a secondary source such as a developer blog. Reuse: release facts (products, versions, dates, links, CVE ids and flags) are open data under CC BY 4.0, from the API at https://whatsnew.fyi/api/v1 or the nightly dataset at https://github.com/whatsnew-fyi/dataset. The summaries, labels and curation are © What's New: quote freely with attribution and a link back; wholesale republication of them is not permitted — terms: https://whatsnew.fyi/terms. The vendors' own release notes remain their publishers'. ## Releases ### 1.23.2b — Release build - 1.23.2b (2026-10-09) - Date: 2026-10-09 - Version: 1.23.2b - Original notes: https://github.com/zen-browser/desktop/releases/tag/1.23.2b - Permalink: https://whatsnew.fyi/product/zen-browser/releases/1.23.2b - **added** — Added an 'open library' command to the command palette - **added** — Right-clicking the media tab in the Library can now disable it - **changed** — Session backup file names now use local dates - **fixed** — The library no longer gets stuck after being opened and closed quickly - **fixed** — Blocked or unsafe downloads now offer the choice to be opened or saved - **fixed** — Moving multiple tabs to a new window no longer irrecoverably loses unloaded tabs - **fixed** — Sidebars no longer have too much minimum width when aligned to the right - **fixed** — HEIC media no longer appears in the media tab without rendering correctly - **fixed** — Space-assigned bookmarks are being saved again - **fixed** — A memory leak issue on startup has been fixed #### Zen Stable Release ##### New Features - Added an 'open library' command to the command palette. - You can now right-click the media tab in the Library to disable it. ##### Fixes - Changed session backup file names to use local dates ([#15806](https://github.com/zen-browser/desktop/issues/15806)) - Fixed the library getting stuck after opening and closing it quickly ([#15833](https://github.com/zen-browser/desktop/issues/15833)) - Fixed blocked/unsafe downloads not having the choice to be opened or saved. ([#15809](https://github.com/zen-browser/desktop/issues/15809)) - Fixed moving multiple tabs to new window irrecoverably loses unloaded tabs. ([#15810](https://github.com/zen-browser/desktop/issues/15810)) - Fixed the sidebar having too much minimum width when they are aligned to the right. ([#15794](https://github.com/zen-browser/desktop/issues/15794)) - Fixed HEIC media being listed in the media tab but do not render correctly. ([#15778](https://github.com/zen-browser/desktop/issues/15778)) - Fixed space-assigned bookmarks not being saved anymore. ([#12721](https://github.com/zen-browser/desktop/issues/12721)) - Fixed a memory leak issue on startup. - Other bug fixes and improvements. ### 1.23.1b — Release build - 1.23.1b (2026-10-06) - Date: 2026-10-07 - Version: 1.23.1b - Original notes: https://github.com/zen-browser/desktop/releases/tag/1.23.1b - Permalink: https://whatsnew.fyi/product/zen-browser/releases/1.23.1b - **security** — Applied Mozilla Firefox security advisory MFSA2026-104 - **changed** — Updated to Firefox 157.0.1 - **added** — Added an option in the Library to filter closed tabs instead of history entries - **added** — Added keyboard shortcut opt/alt + shift + L to quickly open the Library - **added** — Added 'Clear all downloads' option to the Library accessible by right clicking on the downloads section tab - **added** — Added 'Clear history' option to the Library accessible by right clicking on the history section tab - **fixed** — Fixed transparent sidebars having low opacity - **fixed** — Fixed downloads failing on macOS when Firefox is set to ask where to save files but doesn't have permission to access the Downloads folder #### Zen Stable Release ##### Security - https://www.mozilla.org/en-US/security/advisories/mfsa2026-104/ ##### New Features - Updated to Firefox 157.0.1 - Added an option in the Library to filter closed tabs instead of history entries. - A keyboard shortcut (opt/alt + shift + L) has been added to quickly open the Library. - 'Clear all downloads' and 'Clear history' options have been added to the Library by right clicking on the respective section tabs. ##### Fixes - Fixed transparent sidebars having low opacity. - Fixed downloads failing on macOS when Firefox is set to ask where to save files but doesn't have permission to access the Downloads folder. - Other bug fixes and improvements. ### 1.23b — Release build - 1.23b (2026-10-02) - Date: 2026-10-03 - Version: 1.23b - Original notes: https://github.com/zen-browser/desktop/releases/tag/1.23b - Permalink: https://whatsnew.fyi/product/zen-browser/releases/1.23b - **added** — Introduce Library for organizing and accessing history, media, downloads, spaces and more - **added** — Allow resizing the sidebar even when it is hidden, with automatic hiding if resized too small - **added** — Enable WebRTC video calls to use hardware AV1 decoding on supported devices instead of software decoding - **changed** — Update to Firefox 157.0 - **changed** — When a link gets routed to a specific space, prioritize the window that has that space open - **changed** — Add blur effects to elements like the sidebar and command bar - **changed** — Make buttons at the bottom of the sidebar appear larger on macOS - **changed** — Swiping right on the last space now attempts to create a new space - **changed** — Reverse buttons at the bottom of the sidebar when the sidebar is positioned at the right - **fixed** — Improve startup and new window performance when many tabs are open - **fixed** — Make icon animations like the boost indicator and musical notes on the sidebar more performant - **fixed** — Fix status panel and glance controls not using the correct theme colors - **fixed** — Fix HDR videos encoded in 8-bit color formats appearing dull and gray on Windows instead of displaying in HDR - **fixed** — Improve audio and video synchronization when repeatedly changing video playback speed - **fixed** — Fix fullscreen video on Windows leaving the taskbar visible over the video - **security** — Address security advisory MFSA2026-97 #### Zen Stable Release Introducing Library! A better place to organize and access your history, media, downloads, spaces and more. ##### Security - https://www.mozilla.org/en-US/security/advisories/mfsa2026-97/ ##### New Features - Introducing Library! A better place to organize and access your history, media, downloads, spaces and more. - You can now resize the sidebar even when its hidden. If the sidebar is resized too small, it will automatically hide itself. - Updated to Firefox 157.0 - WebRTC video calls can now use hardware AV1 decoding on devices that support it, instead of always decoding AV1 video in software. ##### Fixes - Significant performance improvements on startups/new windows when there are lots of tabs open. - Certain icon animations like the boost indicator or musical notes on the sidebar are now more performant. ([#15299](https://github.com/zen-browser/desktop/issues/15299)) - Fixed status panel and glance controls not using the correct theme colors. ([#15280](https://github.com/zen-browser/desktop/issues/15280)) - Fixed some HDR videos encoded in 8-bit color formats looking dull and gray on Windows instead of displaying in HDR. - Improved audio and video synchronization when repeatedly changing the playback speed of videos, for example on YouTube. - Fixed an issue on Windows where making a video full screen would leave the Windows taskbar showing over the video. ##### Changes - When a link gets routed to a specific space, it will prioritize the window that has that space open. - Some elements like the sidebar and the command bar now appear with blur effects. - On MacOS, buttons at the bottom of the sidebar now appear larger. - Swiping to the right on the last space will now try to create a new space. - When the sidebar is at the right, the buttons at the bottom are now reversed. ### 1.22.3b — Release build - 1.22.3b (2026-09-22) - Date: 2026-09-23 - Version: 1.22.3b - Original notes: https://github.com/zen-browser/desktop/releases/tag/1.22.3b - Permalink: https://whatsnew.fyi/product/zen-browser/releases/1.22.3b - **changed** — Updated to Firefox 156.0.1 - **added** — The command bar now allows you to search through tabs and folders more efficiently - **fixed** — Fixed Zen leaking system handles on Windows as content processes were started and stopped - **fixed** — Fixed context menu actions on the urlbar not working - **fixed** — Fixed overflow-extension order in single toolbar mode - **fixed** — Fixed not being able to install add-ons while in compact mode - **fixed** — Fixed Zen windows on macOS 27 immediately returning to maximized after being restored by double-clicking the title bar #### Zen Stable Release ##### New Features - Updated to Firefox 156.0.1 - The command bar now allows you to search through tabs and folders more efficiently. ##### Fixes - Fixed Zen leaking system handles on Windows as content processes were started and stopped. - Fixed context menu actions on the urlbar not working. ([#15437](https://github.com/zen-browser/desktop/issues/15437)) - Fixed overflow-extension order in single toolbar mode. ([#15419](https://github.com/zen-browser/desktop/issues/15419)) - Fixed not being able to install add-ons while in compact mode. ([#15445](https://github.com/zen-browser/desktop/issues/15445)) - Fixed Zen windows on macOS 27 immediately returning to maximized after being restored by double-clicking the title bar. - Other bug fixes and improvements. ### 1.22.2b — Release build - 1.22.2b (2026-09-15) - Date: 2026-09-16 - Version: 1.22.2b - Original notes: https://github.com/zen-browser/desktop/releases/tag/1.22.2b - Permalink: https://whatsnew.fyi/product/zen-browser/releases/1.22.2b - **security** — Security advisory for Firefox 156.0 applied - **added** — On macOS, Zen can now be set to open automatically when the computer starts up from the Startup section of Settings - **added** — Added 'Expand current view' action to the command bar - **added** — Added 'New space' action to the command bar - **added** — Added 'Reopen closed tab' action to the command bar - **added** — Added 'Duplicate tab' action to the command bar - **added** — Added 'Reset pinned tab' action to the command bar - **changed** — Updated to Firefox 156.0 - **fixed** — Fixed high-sample-rate FLAC audio in MP4 failing to play on certain video sites - **fixed** — Fixed subtitles not appearing in the Picture-in-Picture window when turned on after the window has already opened - **fixed** — Fixed the find bar becoming permanently unavailable in a tab after reversing the panes in Split View - **fixed** — Fixed some sites failing to load when DNS over HTTPS is enabled and the site does not support HTTPS - **fixed** — Fixed an issue on Windows where Zen could block an auto-hiding taskbar from showing - **fixed** — Fixed the sidebar not hiding if the urlbar is open when compact mode is enabled - **fixed** — Fixed an issue where cross-space tab routing would freeze the browser under certain conditions - **fixed** — Fixed cross-device sync losing certain tabs if they are created too quickly - **fixed** — Fixed certain issues related to live folders appearing as active even when there are no tabs showing in them - **changed** — Zen's built-in PDF viewer now starts up to 45% faster - **changed** — Improved memory and CPU usage when Zen displays large JPEG images scaled down to fit a page - **changed** — On Windows devices with ARM64 processors, WebRTC video calls may now use hardware H264 decoding instead of falling back to software #### Zen Stable Release ##### Security - https://www.mozilla.org/en-US/security/advisories/mfsa2026-90/ ##### New Features - Updated to Firefox 156.0 - Zen on macOS can now be set to open automatically when the computer starts up, from the Startup section of Settings. - Added the following actions to the command bar: 'Expand current view', 'New space', 'Reopen closed tab', 'Duplicate tab', 'Reset pinned tab'. ##### Fixes - Fixed high-sample-rate FLAC audio in MP4 failing to play on certain video sites. - Fixed subtitles not appearing in the Picture-in-Picture window when they are turned on in the video player after the window has already opened. - Fixed the find bar becoming permanently unavailable in a tab after reversing the panes in Split View. - Fixed some sites failing to load when DNS over HTTPS is enabled and the site does not support HTTPS. - Fixed an issue on Windows where Zen could block an auto-hiding taskbar from showing. - Fixed the sidebar not hiding if the urlbar is open when compact mode is enabled. ([#13196](https://github.com/zen-browser/desktop/issues/13196)) - Fixed an issue where cross-space tab routing would freeze the browser under certain conditions. ([#14171](https://github.com/zen-browser/desktop/issues/14171)) - Fixed cross-device sync losing certain tabs if they are created too quickly ([#15380](https://github.com/zen-browser/desktop/issues/15380)) - Fixed certain issues related to live folders appearing as active even when they are no tabs showing in them. - Other bug fixes and improvements. ##### Changes - Zen's built-in PDF viewer now starts up to 45% faster. - Improved memory and CPU usage when Zen displays large JPEG images scaled down to fit a page. - On Windows devices with ARM64 processors, WebRTC video calls may now use hardware H264 decoding instead of falling back to software. - Live Folders will now ignore archived issues and pull requests. - Improved the look and feel of drag-and-drop interactions for tabs. Specially on MacOS, where the drag-and-drop behavior is now done natively. - Folders will now fully-expand if all tabs within them are visible. Folder animations has also been improved for smoother transitions. ### 1.22.1b — Release build - 1.22.1b (2026-09-11) - Date: 2026-09-12 - Version: 1.22.1b - Original notes: https://github.com/zen-browser/desktop/releases/tag/1.22.1b - Permalink: https://whatsnew.fyi/product/zen-browser/releases/1.22.1b - **added** — Add option to sync normal tabs across devices along with Spaces, Folders, and other data in Settings > Sync > Sync your Spaces across devices - **added** — Add ability to share Spaces, folders and split views to other Zen users and non-Zen users via shareable link accessible from context menu - **fixed** — Improve performance and battery usage while scrolling and playing videos #### Zen Stable Release ##### New Features - You now have the option to sync normal tabs across devices along with your Spaces, Folders, and other data. This can be enabled in Settings > Sync > Sync your Spaces across devices. - You can now share Spaces, folders and split views to other Zen users and non-Zen users via a shareable link. This can be found in the context menu of a Space, folder or split view. ##### Fixes - Noticeably improved performance and battery usage while scrolling, and playing videos. - Other bug fixes and improvements. ### 1.22b — Release build - 1.22b (2026-09-04) - Date: 2026-09-05 - Version: 1.22b - Original notes: https://github.com/zen-browser/desktop/releases/tag/1.22b - Permalink: https://whatsnew.fyi/product/zen-browser/releases/1.22b - **security** — Security vulnerability addressed per Mozilla security advisory MFSA2026-82 - **changed** — Updated to Firefox 155.0 and 155.0.1 - **added** — Sync Spaces, Folders, Tabs, and other data between devices using Mozilla account via Settings > Sync > Sync your Spaces across devices - **changed** — Chrome UI redesigned with squircles and other visual design elements for improved appearance - **added** — New onboarding experience added to help new users get started with the browser and its features - **changed** — Creating a new Space is now faster with reduced animation wait time - **added** — Containers can now be reordered in Settings with the new order applied wherever containers are listed - **fixed** — Fixed live folders for GitHub issues not working with the new GitHub UI - **fixed** — Fixed Zen preventing Linux systems from going to sleep after a long browsing session - **fixed** — Fixed arrow-key and Page Up/Down scrolling not working on some pages with embedded content from other sites - **fixed** — Fixed live audio streams such as internet radio stopping when playing in the background - **changed** — Font size increased for sidebar text to improve readability and navigation - **changed** — Captive portal detection now uses firefox-portal-detection.com instead of detectportal.firefox.com, requiring network allowlist updates - **changed** — PDFs smaller than paper size can now be enlarged to fill the sheet when printing by setting the scale above 100% #### Zen Stable Release ##### Security - https://www.mozilla.org/en-US/security/advisories/mfsa2026-82/ ##### New Features - Updated to Freifox 155.0 and 155.0.1 - 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. - The chrome UI now has a better look and feel, implementing squircles and other design elements to make it more visually appealing. - A new on-boarding experience has been added to help new users get started with the browser and its features. - Creating a new Space is now faster and requires less animation wait time, making the process more efficient. - Containers can now be reordered in Settings, and the new order is used wherever containers are listed. ##### Fixes - 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. ##### Changes - Font size has been increased for the sidebar text, making it easier to read and navigate through tabs and spaces. - 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. - PDFs smaller than the paper size can now be enlarged to fill the sheet when printing, by setting the scale above 100%. ### 1.21.16b — Release build - 1.21.16b (2026-08-28) - Date: 2026-08-29 - Version: 1.21.16b - Original notes: https://github.com/zen-browser/desktop/releases/tag/1.21.16b - Permalink: https://whatsnew.fyi/product/zen-browser/releases/1.21.16b - **changed** — Update Firefox version to 154.0.1 - **fixed** — Improved session store performance, lowering CPU usage spikes and disk usage when storing the session - **fixed** — Fixed duplicate separator on tab context menu - **fixed** — Fixed minimizing PiP window failing to collapse into the sidebar - **fixed** — Fixed slower access to saved passwords and unexpected Primary Password prompts caused by recent changes to password storage - **fixed** — Fixed an issue where addresses were failing to autofill on some sites #### Zen Stable Release ##### New Features - Update Firefox version to 154.0.1 ##### Fixes - Improved on session store performance, lowering CPU usage spikes and disk usage when storing the session ([#14990](https://github.com/zen-browser/desktop/issues/14990)) - Fixed duplicate separator on tab context menu ([#15031](https://github.com/zen-browser/desktop/issues/15031)) - Fixed minimizing PiP window failing to collapse into the sidebar ([#14710](https://github.com/zen-browser/desktop/issues/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. ### 1.21.15b — Release build - 1.21.15b (2026-08-18) - Date: 2026-08-19 - Version: 1.21.15b - Original notes: https://github.com/zen-browser/desktop/releases/tag/1.21.15b - Permalink: https://whatsnew.fyi/product/zen-browser/releases/1.21.15b - **security** — Address security advisories from Mozilla Firefox - **changed** — Update Firefox version to 154.0 - **added** — Local Zen profile backups are now available on macOS in addition to Windows and Linux, and backups can be restored across all three platforms - **added** — 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 - **added** — The full-page Translations feature now translates iframe content - **changed** — The full-page Translations feature now runs language identification on all page loads - **changed** — Performing a hard reload on a page now also clears and updates its cached favicons - **fixed** — Improved battery life on macOS when using vibrancy effects - **fixed** — Improved performance of session restore by reducing CPU usage spikes when storing session to disk - **fixed** — Fix multiple glance tabs when joining tabs - **fixed** — Improved rendering performance on macOS and reduced memory leaks when using WebRTC - **fixed** — Fixed an issue on macOS where closing a browser window could leave behind an invisible window that continued to capture mouse clicks - **fixed** — 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** — Fixed an issue where the Windows taskbar would appear in front of a full screen Picture-in-Picture window - **fixed** — Fixed PDF documents not being scaled correctly in print preview when the Fit to Page Width option is used #### Zen Stable Release ##### Security - https://www.mozilla.org/en-US/security/advisories/mfsa2026-74/ ##### New Features - 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