# Firefox 154.0 - Product: Firefox (https://whatsnew.fyi/product/firefox) - Vendor: Mozilla - Date: 2026-08-18 - Version: 154.0 - Original notes: https://www.mozilla.org/en-US/firefox/154.0/releasenotes/ - Permalink: https://whatsnew.fyi/product/firefox/releases/154.0 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: the summaries, labels and curation here are © What's New. Quote freely with attribution and a link back; wholesale republication of the corpus is not permitted — terms: https://whatsnew.fyi/terms. The vendors' own release notes remain their publishers'. --- - **added** — Firefox's Local Network Access protections now extend to WebSocket connections - **added** — Smart Window can now suggest groups of related tabs and propose a name for each group - **added** — Firefox on Windows is now a supported browser for NVIDIA GeForce NOW - **added** — Local Firefox 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 - **added** — Windows users can now choose a different Firefox app icon in Settings - **added** — The address bar now includes a Manage AI quick action that opens the AI controls in Settings - **added** — Performing a hard reload on a page now also clears and updates its cached favicons - **added** — Added a time picker user interface to input type="time" and input type="datetime-local" - **added** — Firefox now supports the text-box-trim and text-box-edge CSS properties and the associated text-box shorthand - **added** — Firefox now supports the sibling-index() and sibling-count() CSS functions - **added** — Added support for the No-Vary-Search HTTP response header for the HTTP disk cache - **added** — Firefox now supports Iterator.prototype.chunks and Iterator.prototype.windows methods - **added** — Firefox now supports Iterator.prototype.includes() - **added** — Firefox now supports the Iterator.prototype.join method - **changed** — The full-page Translations feature now runs language identification on all page loads - **changed** — Video seeking is now significantly faster on all operating systems - **changed** — 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 - **changed** — Firefox View is moving out of the toolbar by default for new profiles and for profiles where it hasn't been used recently - **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 Firefox 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 the Vertical Tabs sidebar staying visible in full screen mode - **fixed** — Fixed PDF documents not being scaled correctly in print preview when the Fit to Page Width option is used ###### New - Firefox's Local Network Access protections now extend to WebSocket connections. Websites that try to open a WebSocket to a device on the local network will now ask for permission first. - In Smart Window, Firefox can now suggest groups of related tabs and propose a name for each group. This feature is part of a progressive roll out. What is a progressive roll out? Certain new Firefox features are released gradually. This means some users will see the feature before everyone does. This approach helps to get early feedback to catch bugs and improve behavior quickly, meaning more Firefox users overall have a better experience. - Firefox on Windows is now a supported browser for NVIDIA GeForce NOW, letting users stream supported PC games directly in the browser. - Local Firefox 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