# Release notes for version 1.23b By Steven Van · 2026-10-01 Zen Browser 1.23b adds a Library for history and downloads, moves to Firefox 157.0, and fixes slow startups with many tabs open. Zen Browser 1.23b adds a Library, a single place to organize and get to history, media, downloads, spaces and more. The release also updates the browser to Firefox 157.0 and fixes a number of performance and playback problems. The full list is in the [release notes](), and the browser is listed on our site as [Zen Browser](). ## Features - Library: a new place to organize and access history, media, downloads, spaces and more. - The sidebar can now be resized even when it is hidden. If it is resized too small, it hides itself automatically. - Updated to Firefox 157.0. - WebRTC video calls can now use hardware AV1 decoding on supported devices. ## Fixes - Startup and new windows are significantly faster when many tabs are open. - Icon animations such as the boost indicator and the musical notes on the sidebar are more performant. - The status panel and glance controls now use the correct theme colors. - Some HDR videos encoded in 8-bit color formats no longer look dull and gray on Windows, and display in HDR instead. - Audio and video stay better in sync when the playback speed is changed repeatedly, for example on YouTube. - On Windows, making a video full screen no longer leaves the taskbar showing over it. ![Zen Browser]() Zen Browser Privacy-focused, beautifully designed browser built on Firefox — split views, workspaces, and a minimal UI for focused browsing. [View Zen Browser →]() Sources [Original source]() [Read Release notes for version 1.23b on Creators Toolbox]() --- Canonical source: https://creatorstoolbox.com/blog/zen-browser-release-notes-for-version-1-23b