Firefox Nightly
Release Notes

Fixed quick gamepad button presses sometimes being missed in web games on macOS.

Fixed tabs sometimes detaching into a new window when clicked on Linux with Wayland.

Fixed long drop-down lists on web pages sometimes showing blank space in place of the last options until the list was scrolled.

Fixed menus and panels fading in on Windows and Linux when animation effects are turned off in the operating system.

Fixed some videos displaying incorrectly on Windows when NVIDIA RTX Video HDR is enabled.

Fixed bookmarks not being imported from Google Chrome profiles that are signed in to a Google account.

Fixed some sites, such as Slack, failing to load instead of falling back to HTTP/2 when the site rejected an HTTP/3 request.

Fixed the Replace button in Apple Writing Tools on macOS inserting the clipboard contents instead of the rewritten text on some sites, such as Gmail.

Fixed the file upload dialog opening in the last folder a file was saved to, such as Downloads, instead of the folder last used for uploads.

Fixed memory usage growing rapidly when sites such as the Zoom web app were left open in a minimized window.

Open tabs can now be searched with a keyboard shortcut: Ctrl+Shift+A on Windows and Linux, Cmd+Shift+A on macOS. The Extensions and Themes shortcut is now Ctrl+Shift+F on Windows and Linux, and Cmd+Shift+E on macOS. These shortcuts can be changed in about:keyboard.

Starting with Firefox 159, Firefox Nightly on macOS selects the word or link under the pointer when right-clicking like other macOS apps.

Web addresses written in the Javanese, Balinese, Canadian Aboriginal Syllabics, and N'Ko scripts are now displayed in their own script instead of as encoded "xn--" text.

The AI chatbot's Summarize page option now shares the page's address with the chatbot provider instead of the page's text content.

On macOS, apps that sign in through the default browser, such as ChatGPT, now open their sign-in page in Firefox instead of Safari when Firefox is the default browser.

The Web Console now allows let, const, and class variables to be declared again, so a snippet can be edited and re-run without a redeclaration error.

Starting with Firefox 156, in Nightly builds the centering of content inside buttons and text inputs is now expressed with align-content in the built-in stylesheet, so pages can override it.

Starting with Firefox 156, Firefox Nightly supports Scoped Custom Element Registries. Those registries can be created using the CustomElementRegistry() constructor that are separate from the global window.customElements registry. Creating more than one registry is useful for multiple custom elements that have the same tag name to coexist.

Starting with Firefox 158, Firefox Nightly supports the corner-shape property, including all corner-*-shape longhand properties, allowing to change the shape of the corners of an element.

Starting with Firefox 158, Firefox Nightly now supports the random() CSS function, which allows authors to introduce randomness into their styles, generating a random value in a given range (with an optional increment) that is usable anywhere that math functions can be specified.

Starting with Firefox 158, Firefox Nightly now supports streaming uploads with the Fetch API, allowing web applications to send request bodies incrementally using a ReadableStream without buffering the entire body first.

Firefox now supports scoped custom element registries. A registry created with the CustomElementRegistry() constructor is separate from the global window.customElements registry, so custom elements that share a tag name can coexist on the same page.

Firefox now supports scroll-driven animations, so CSS animations and Web Animations API animations can progress with the scroll position of a container or with an element's visibility as it scrolls into view, using the animation-timeline, scroll-timeline, view-timeline, and animation-range properties and the ScrollTimeline and ViewTimeline interfaces.

The Sanitizer API now sanitizes HTML as it is parsed rather than afterwards, so custom element constructors no longer run for elements the sanitizer removes.

On compatible devices, WebGL now supports the EXT_clip_control and EXT_texture_mirror_clamp_to_edge extensions and WebGL 2 supports EXT_texture_norm16.

The WebGL extension EXT_clip_control is now available on compatible devices.

The WebGL extension EXT_texture_mirror_clamp_to_edge is now available on compatible devices.