Highlights

• Rév O’Conner added a settings popup to control the layout of the Inspector. “Auto” automatically switches the layout at a given toolbox width.
  • 
• The new sidebar (sidebar.revamp) and switcher setting will be enabled by default for users along with Nova in DevEdition, Beta and Release channels. To ease the transition for old sidebar users, the “Open tools from sidebar” option will be unchecked for those users to more closely resemble the old sidebar experience. The migration won’t apply to users who had already tried the new sidebar and reverted back.
• The custom wallpaper library for the New Tab page is coming along! This allows you to save multiple images to your wallpaper folder, rather than replacing one image at a time. While it’s still in development, you can test it by setting browser.newtabpage.activity-stream.newtabWallpapers.customWallpaper.library.enabled to true, starting in Firefox 157.
  • 
• Mark added an MDN search engine for Nightly and Developer Edition. Select it from the menus, or type @mdn <search term>.
  • 
  • 

Friends of the Firefox team

Resolved bugs (excluding employees)

Script to find new contributors from bug list

Volunteers that fixed more than one bug

• :Benjamin Peterson
• Amadi
• any1here
• Caleb Pickard
• Chris Vander Linden
• Gopalarathnam Venkatesan
• Igor [:ExplodingJoysticks]
• Khalid AlHaddad
• Lukáš Lipinský
• Mayank Bansal
• Nazeer Ahmed Shaikh
• Noah Varghese
• Sameem [:sameembaba]
• Sebastian Zartner [:sebo]
• sfshah
• Xiaosen Zhuang

New contributors (🌟 = first patch)

• Amadi:
  • Network monitor opens files in last tab
  • Remove the unused _discarded field in UrlbarParentController.sys.mjs
  • Update comments that point at the removed openUILinkIn function
  • Screenshot default filename contains trailing whitespace on pages without title
• Caleb Pickard
  • 🌟 Remove BROWSER_SEARCH_PREF constant
  • The phrase “The count URI loads…” appears repeatedly in the search telemetry code. It should read “The count *of* URI loads…”
• dchen705: Remove unnecessary module import in browser/components/urlbar/tests/browser/head.js
• Ekerin Agboola: Remove old documentation related to the removed SEARCH_SUGGESTIONS_LATENCY_MS histogram
• Igor [:ExplodingJoysticks]:
  • Cleanup dead code in PageThumbs (preserveAspectRatio)
  • Dead code in services/crypto/modules/utils.sys.mjs#
• Gopalarathnam Venkatesan:
  • “Add class” button (.cls) should be disabled when a class can’t be added to the selected node
  • Remove unused lightweightThemes.getMoreURL pref
  • Remove orphaned selectHistoryMode JSDoc from browser/components/preferences/tests/privacy/head.js
  • gBrowser.selectedTabs does not return tabs in tab order
• 🌟 Jieke Jiang: Remove unused AboutReaderParent._getArticle
• 🌟 Andrew: White flash on startup caused by abouthome_cache storing  incompatible startup frame
• 🌟 Rév O’Conner: Inspector does not respect panel layout
• 🌟 Kana: browser_privatebrowsing_resetPBM.js awaits an array instead of Promise.all, so the tab-close wait does nothing
• Raúl: L10nCache.add() throws on an unknown Fluent ID instead of reporting it
• 🌟 Samuel Mbabhazi: Use new color syntax throughout the DevTools
• K: “Go to line” sets a cursor line which does not exist in footer location indicator
• sfshah:
  • Turn devtools/client/jsonview/converter-child.js into an ES class
  • 🌟 Fix misspellings in SearchService.shouldShowInstallPrompt
• Nazeer Ahmed Shaikh
  • Remove deprecated logs from tt(c) harness
  • 🌟 test_dont_suggest_default_engine task is duplicated in browser_contextualsearch.js mochitest
• Noah Varghese:
  • Make browser/components/syncedtabs/sidebar.xhtml an HTML file
  • 🌟 Remove usages of “six” from toolkit/components/telemetry/tests/marionette/
• Valerie Racine (:v-racine): Fix incorrect assertion message in browser_adoptTab_failure.js
• 🌟 Xiaosen Zhuang:
  • Fix the undefined –border-color-dead-row custom property in aboutMemory.css
  • Use documentGlobal instead of the removed ownerGlobal in FormAutofillPreferences

Project Updates

Add-ons / Web Extensions

Addon Manager & about:addons

• As part of Project Nova related work:
  • Fixed responsive layout issues that caused horizontal scrolling in about:addons at high zoom levels – Bug 2059864
  • Fixed the “Discover extensions” button appearing multiple times in about:addons – Bug 2070281
  • Added telemetry for theme-picker shown events and for appearance/native-theme changes in about:addons – Bug 2069417 / Bug 2070341
  • Added an accessible name to the themes mode control in about:addons, fixed in Firefox 158 and uplifted to the Firefox 157 beta channel – Bug 2064563
    • Thanks to Mark Kennedy for the help on fixing this accessibility gap
  • Updated the built-in dark and light theme previews to use the nova style – Bug 2070274
    • Thanks to Emilio Cobos Álvarez for the fix to the default light and dark theme previews.
  • Fixed the Nova default and AMO curated theme previews to follow the OS light/dark mode while ignoring the Website appearance setting, fixed in Firefox 158 and uplifted to the Firefox 157 beta channel – Bug 2070562
• Stopped setting unused taarId session cookies for AMO on startup – Bug 1871561
  • Thanks to Manuel Bucher for helping us to clean up these unused internals.

WebExtension APIs

• Fixed webRequest requestBody parsing so POST form fields named __proto__ are no longer dropped – Bug 2061470
• Changed alarms.clearAll() to resolve with undefined instead of a boolean, starting in Firefox 157 – Bug 2067229
  • Thanks to Ollie Hensman-Crook for the fix to the alarms API.
• Implemented native messaging support via xdg-native-messaging-proxy for Flatpak and Snap builds – Bug 1955255
  • Thanks to Jan Horak for the native messaging work on Linux packaging.
• As part of Florian Quèze effort to investigate and fix intermittent failures:
  • Made windows.update() wait for the window to actually resize or move before resolving, fixing an intermittent Linux test failure – Bug 1307759
  • Fixed a pageAction popup incorrectly opening via a commands API shortcut while the extension was already shutting down – Bug 2039637
  • Fixed action.openPopup() rejecting when a tab hover preview was showing, a regression from Bug 2022281 in Firefox 150, with the fix shipping in Firefox 157 and no uplift planned – Bug 2062229

DevTools

• The team has a few sizable ongoing projects.
  • Bomsy is working on moving Stylesheets to the Debugger so we can retire the (XUL-based) Style Editor, and turn the Debugger into a “Sources” panel (keeping all the existing functionality of course).  (pref: devtools.debugger.features.stylesheets-in-debugger)
  • Alex is investigating ways to better handle CSS authored text and CSSOM changes in the Inspector, building information directly from the Rust CSS engine, with the hope it will bring performance improvement editing styles in the Rules view.
  • Nicolas is implementing a way to show to the user how the engine goes from a CSS declaration value to the computed value so it’s easier to follow what’s the result of the different call sites, or how the different units (em, %, vmin, …) are computed to their final (e.g. px) values.   (pref: devtools.inspector.css-explainers)

External contributions

• Chris Vander Linden finalized a multi-months project to add a search toolbar in the Netmonitor Raw Response panel, adapting and reusing the component we are using in the Debugger (#1941575)
  • 
• Amadi made the “Open in new tab” context menu entry to open tab next to the selected tab, not at the very end of the tab list (#2059979)
• Mayank Bansal optimized the performance of console.clear() (#2068156, #2068157, #2067000)
• Benoit added JSON Lines (JSONL/NDJSON) support in the Netmonitor Response panel (#2059673)
• Gopalarathnam Venkatesan made the “Add class” button (.cls) to be disabled when a class can’t be added to the selected node (e.g. it’s a text node, or a comment, or the doctype node) (#2000150)
• K fixed an issue with the “Go to line” action in the Debugger (#2064575)
• Samuel Mbabhazi refactored our CSS codebase to use new color syntax (e.g. rgb(255 0 0) instead of rgb(255, 0, 0)) (#2054228)
• sfshah turned devtools/client/jsonview/converter-child.js into an ES class (#2004273)

Team/Project Update

• Florian Quèze [:florian] is working on fixing test flakiness in devtools/client/debugger and already landed an impressive stack of patches (#2001947, #2070917, #2070920, #2070932, #2070970, #2027953, #1932082, #2070923, #2070933, #1814093, #1868969, #2071238)
  • that also includes fixing various accessibility issues that were spotted by a11y_checks #2070911, #2070955, #2071227, #2071231)
  • Note that Julian Descottes [:jdescottes] also has an ongoing quest to reduce intermittent failures in our codebase and fixed a few those last 2 weeks (#1767707, 2069100, #2009386)
  • [florian] 24 patches landed on Friday, you can see the impact on https://tests.firefox.dev/tests.html?path=devtools%2Fclient%2Fdebugger
• Nicolas Chevobbe [:nchevobbe] fixed a few issues spotted by Jake in the Inspector for the new-ish attr()CSS function (#2068479, #2068480, #2068483)
• Alexandre Poirot [:ochameau] fixed an OOM crash when viewing source mapped file for a large wasm module with many workers (#2058286)
• Julian Descottes [:jdescottes] improved performance of the Inspector when Devtools was opened on a page with many grid elements (#1988868)
• Hubert Boma Manilla (:bomsy) fixed an infinite loop in the Debugger search if you were searching for $ on a big JS file (#2068517)

WebDriver

• Sameem merged two internal helpers (remote/shared/Sync.sys.mjs and remote/marionette/sync.sys.mjs) which removed some code duplication.
• Khalid AlHaddad unified the navigation commands in Marionette and WebDriver BiDi to always initiate navigations via browsingContext.loadURI().
• Khalid AlHaddad updated the WebDriver BiDi client used by WebDriver tests so that browsing_context.locate_nodes returns the nodes array directly instead of the enclosing result object, matching the updated command response.
• Julian Descottes made the destinationFolder mandatory when calling the browser.setDownloadBehavior command with type=”allowed” – which aligns us with the specification. In order to restore the default behavior without having to specify a folder, clients should call setDownloadBehavior with null instead.
• Henrik Skupin fixed a bug in geckodriver where specifying androidIntentArguments in the capabilities caused the default intent arguments to be omitted.

Fluent

• According to arewefluentyet.com, ~74.77% of our strings are now using Fluent!

Lint, Docs and Workflow

• According to arewemozsrcyet.com, ~59% of our modules are now using moz-src.
• eslint-plugin-mozilla has switched from using Mocha to Jest for tests.
  • Planning on future updates to investigate getting devtools & newtab to use the jest installed at the top-level, rather than separately installed copies.

Information Management/Sidebar

• We’re working away on bug fixes for sidebar, vertical tabs, split-view, and Nova
• Thanks Florian (:fqueze) for landing a set of patches that have markedly reduced test flakiness in the Sidebar component

New Tab Page

• Custom wallpaper library
  • Dre added a “Your images” folder to the wallpaper picker on the New Tab Page, letting users save and switch between multiple custom wallpapers directly from the picker UI (desktop channels), which reduces friction for users who frequently change backgrounds.
  • Dre implemented storage and migration for multiple custom wallpapers so users keep their existing wallpaper during upgrade while gaining the ability to save and switch multiple wallpapers — migration moves old single-wallpaper prefs into the new multi-wallpaper storage and the NTP now reads the wallpaper array at load/sync points.
  • Dre updated New Tab Page strings to support multiple custom wallpapers so users now see accurate, localized labels and accessibility text when managing or switching between multiple custom backgrounds, reducing confusion in the UI during wallpaper selection.
  • Dre added a delete affordance for saved custom wallpapers inside the New Tab Page picker so users can remove unwanted images from their saved set without going to profile files or prefs, improving manageability of user-provided wallpapers.
• We’ve completed a mass migration of our unit tests from Mocha (not mochi) / Karma to Jest/RTL, which is more modern and actively maintained.
• Sections is now enabled globally for all regions that show the content feed!
• Reem Hamoui fixed Lists widget so that keyboard users can now tab to completed items on the New Tab Page and see a visible selection/focus state
• Reem Hamoui fixed the Timer widget so that keyboard users can toggle focus vs break modes with standard keys (Enter/Space/arrow keys) thanks to restored keyboard handlers and tabindex semantics.
• Reem Hamoui made it so that screenreaders now announce wallpaper names via added aria-labels/alt text and role improvements in the Customize UI.
• Maxx Crawford made it so that the Customize UI now filters wallpapers by their metadata and no longer surfaces images marked hidden or in specific visibility groups.
• Irene Ni added Section Layout Name (String) telemetry to newtab content impression & click events so impressions/clicks now carry layout identifiers for more granular UX and A/B analysis
• Reem Hamoui added accessible names (aria-label/aria-labelledby) to the HNT Customize panel back buttons to fix screen-reader discoverability and keyboard/AT announcement when navigating the New Tab Customize flow.
• Nina Pypchenko [:nina-py] preserved iframe rendering for New Tab Page widgets during drag operations to prevent iframe-backed widgets from going blank while being moved.
• Nina Pypchenko [:nina-py] restored the Stocks widget dropdown and menu visibility under High Contrast Mode by adjusting contrast-aware CSS and ARIA roles so users relying on HCM can access stock controls again.
• Nina Pypchenko [:nina-py] fixed a results text overflow for long search queries in the Stocks widget by adding word-wrap/clamping to result lines, preventing layout breakage and truncated controls when users enter long symbols or queries.
• Nina Pypchenko [:nina-py] added telemetry for theme selection in the New Tab customization panel by emitting a selection ping on change, enabling measurement of user theme choices without changing UX.
• Irene Ni restored the Lists widget switcher checkmark for the selected list by fixing menu item selection-state rendering so users can again see which list is active in the switcher.
• Reem Hamoui updated the Privacy widget CTA and spacing on the New Tab Page, adjusting CSS/layout and CTA copy so the action is more discoverable and has a clearer tap/click target across responsive breakpoints.
• Reem Hamoui updated the zero-state copy for the New Tab Privacy widget to clarify what the widget does and the next steps for users when no privacy events or trackers are present, reducing confusion for first-time or cleared-state users.
• Maxx Crawford landed Fluent strings for the Nova launch New Tab customization callout, enabling localized text in the New Tab customization callout so users in supported locales see translated UI instead of missing-string fallbacks.
• Nina Pypchenko made the customization panel reset when closed, ensuring about:newtab customization state (temporary tile/layout previews) is cleared on close so users no longer see stale previews when reopening the panel.
• Dão Gottwald fixed New Tab to pick up system High Contrast Mode on Linux and macOS, restoring correct high-contrast colors/contrast on those platforms for users who rely on OS-level accessibility settings.
• Irene Ni restored theme matching for New Tab context menus by reapplying theme-aware CSS variables in the New Tab Page contextmenu styles, fixing mismatched colors for users with custom/light/dark themes.
• Dustin Whisman fixed New Tab section context menu button color regression by adjusting the section-contextmenu button style rules (button color variables and state selectors) so section actions now respect theme contrast.
• Irene Ni restored transparency to New Tab card backgrounds by removing opaque background rules so cards correctly display background images/themes and improve visual consistency across DPI/compositing setups.

Picture-in-Picture

• Thanks to Sebastian Zartner [:sebo] for fixing broken Dailymotion captions on the PiP player.
• kpatenio fixed YouTube’s displayed playback speed settings being out of sync with PiP.
  • Reminder that the playback speed settings can be enabled with media.videocontrols.picture-in-picture.playback-speed.enabled.
  • 
• Thanks to Sylvestre Ledru [:Sylvestre] for helping fix a broken link in our PiP docs as a part of Bug 2071683.

Search and Urlbar

Address Bar

• Dao and Moritz are working on bringing the full urlbar experience into the newtab page, now enabled on nightly and going through polish and improvements.. (Bug 2068104, Bug 2068633, Bug 2069260, Bug 2064747)
• Drew enabled AMP and Wikipedia by default in AT, BE, CH, ES, IE, LU, NL, PL, PT and SE. (Bug 2066294)
• James gated adaptive autofill page results behind a minimum score threshold. (Bug 2066171)
• any1here stopped disabled Manage AI and Labs quick actions being displayed when disabled. (Bug 2070378)

Search

• Dale landed the Recent Searches widget which will be be used launched as an experiment (Bug 2063718)
  • 
• Caleb fixed the search box eating the first character typed into it. (Bug 1953361)
• Mark configured Wikipedia search for Sardinian (sc) to use the Sardinian Wikipedia rather than the Italian one. (Bug 2057690)

Places

• Marco fixed bookmarked Google Maps using Google’s default favicon. (Bug 1575809)
• Marco fixed the Downloads and History windows going full-screen instead of floating on macOS. (Bug 2058062)

Tests

• Dashboards:
  • Most frequent oranges: https://tests.firefox.dev/intermittent.html#date=21days
  • Folders with the most flaky tests: https://tests.firefox.dev/flaky.html?kind=mochitest#date=21days&view=list
  • Issues of tests in a given folder: https://tests.firefox.dev/tests.html
    • Eg devtools debugger tests shows progress of the recent effort to fix these tests recently
• Flakiness burn down
  • Multi-agent Claude sessions running for hours investigating and fixing tests of a given set provided in the prompt. Still iterating on the process. Did this 3 times so far:
    • Bug 2062142 – [meta] Fix the flakiness in browser/components/extensions/test/browser
    • Top 20 intermittent mochitest bugs annotated by sheriffs.
      • Probably what made the mochitest line go down for the first time on https://tests.firefox.dev/
      • And what helped with the sidebar component, even though sidebar wasn’t my target.
    • Bug 2070797 – [meta] Fix the flakiness in devtools/client/debugger/test/mochitest
      • https://tests.firefox.dev/tests.html?path=devtools%2Fclient%2Fdebugger%2Ftest%2Fmochitest
• Profile your claude session for cost and context size: https://github.com/fqueze/claude-profiler
  • To monitor cost during your sessions, try https://github.com/padenot/foxtail

Highlights

• Want some Kit? Check out the store!
  • 
• Sebastian Zartner [:sebo] added a panel to expose @media emulation (#1692434) and provided a way to emulate @media (prefers-reduced-motion: reduce) (#1477920)
  • 
• More theme controls have been added to the New Tab customization panel:
  • 
• Improved Picture-in-Picture caption support from some volunteer contributors
  • Thanks to Lukáš Lipinský for adding caption support to Česká televize!
  • Thanks to kernp25 for adding caption support to ardmediathek.de!

Friends of the Firefox team

Resolved bugs (excluding employees)

Script to find new contributors from bug list

Volunteers that fixed more than one bug

• :Vincent
• japandi
• Nirmal Advani
• Sebastian Zartner [:sebo]
• tanvi.manku

New contributors (🌟 = first patch)

• Aditi: Increase the maximum number of PDF.js preferences
• 🌟 Anil Verman: [Docs] Trigger listeners doc is seriously out of date
• Fede: more than six thumbnails needed when Ctrl+Tab is used
• Giulio B: frameId is wrong in webRequest events triggered via importScripts
• 🌟 Luiz Henrique Vieira: Remove dead CSS rule .alltabs-item[selected=”true”] 
• 🌟 Devin Rousso: `emulation.setLocaleOverride` does not override `Accept-Language` header for in `Worker` for `fetch` and `WebSocket`
• 🌟 muhammad shaikh: Profile delete page heading should enclose profile name in quotes
• 🌟 Kevin Gosse: nsDataObj::QueryGetData in Firefox returns E_FAIL for formats it doesn’t carry, instead of DV_E_FORMATETC per the COM contract
• Lukáš Lipinský: Česká televize captions do not display in the Picture-in-Picture window
• 🌟 mikey gough: Remove three unused devtools.debugger.file-search-* preferences
• 🌟 Nathan Leuz: Remove unused legacy preference browser.translation.neverForLanguages
• 🌟 Shawn Zivontsis: Reorder moz_origins composite unique index to UNIQUE(host, prefix)
• tanvi.manku:
  • Remove or update metrics expiring at the end of Firefox 154: pwmgr.doorhanger_submitted_* before Gecko switches to version 155 on 2026-07-20
  • unnecessary scrollbars in edit dialogs for payments and addresses
• 🌟 Tim McNulty: Remove always-true clause from NS_ASSERTION in nsNavBookmarks::AdjustIndices (Coverity CID 1274453)

Project Updates

Add-ons / Web Extensions

Addon Manager & about:addons

• As part of Nova about:addons work:
  • Introduced a shared localization module for built-in and curated AMO-hosted theme names, and updated the corresponding about:addons theme test to expect the new “Default” theme name shown when Nova is enabled – Bug 2055936 / Bug 2058235
  • Added a message bar to the about:addons themes picker to surface AMO-hosted Nova theme download and install failures instead of failing silently – Bug 2054548

WebExtensions Framework

• Fixed a startup race where an extension’s restored dynamic content scripts could be missing from the parent WebExtensionPolicy due to stale shared data – Bug 2058719

WebExtension APIs

• Fixed publicSuffix.isKnownSuffix() to reject invalid domain-name characters, including wildcard suffixes, that could previously be matched as a known public suffix – Bug 2059819
• Fixed the frameId reported by webRequest events for requests made from workers, including importScripts()-loaded scripts, which were previously attributed to the wrong frame – Bug 2048884
  • Thanks to Giulio B for the fix to webRequest frameId attribution for worker requests.

DevTools

• Benoit made it possible to display JSON Lines (JSONL/NDJSON) documents in the JSON Viewer (#2055774)
  • 
• Leo McArdle [:leo] continues his quest to add MDN icons next links to MDN (#2049610, #2050159)
• Julian Descottes [:jdescottes] vastly improved DevTools screenshot performance (by up to 35%) (#2056716)
• Hubert Boma Manilla (:bomsy) fixed keyboard navigation for about:debugging (#2050797)
• Julian Descottes [:jdescottes] fixed a bug that was preventing to show error messages in about:debugging (#2058021)
• Nicolas Chevobbe [:nchevobbe] made ::checkmark pseudo element visible in the Inspector (#2009909)
  • Used by customizable select (MDN)
  • Preference: dom.select.customizable_select.enabled
  • 

WebDriver

• Nirmal Advani cleaned up our codebase by removing the executeSoon helper, which was just a thin wrapper on top of Services.tm.dispatchToMainThread().
• Sameem removed support for the “contexts” argument in the “session.unsubscribe” command. From now on, clients can unsubscribe only by event names or subscription ids.
• John Schanck added support for validating if an authentication id is stored in the Virtual Authenticator Database.
• Alexandra Borovova disabled the download panel to prevent the loss of the focus of the current document when a download begins.

Fluent

• Here are utilities for measuring localization coverage at runtime

Lint, Docs and Workflow

• Sylvestre has converted all our in-tree documents to be Markdown instead of reStructuredText.
• Standard8 adjusted the source doc upload task, that runs on code review, to report failures into phabricator, rather than having a generic error message.
• Standard8 made it so that test-manifest-toml issues for out-of-order entries should show up in phabricator more often.
• https://arewemozsrcyet.com/ continues to head (mostly) in the right direction.

New Tab Page

• HNT Eng had a work week last week. Did a lot of prep for big cleanups (Nova, Widget cleanup post WCW)
  • Also worked on ways to automate trainhops / make them easier to deploy
• Jack Brown updated newtabTrainhopAddon to allow co-enrollment and prioritize the highest version number, which ensures the New Tab Page picks the newest addon build when multiple enrollments overlap and prevents older experiment variants from replacing newer installs.
• Fred Chasen fixed AccuWeather sponsored text overlapping the “Tell us what you think” link by adjusting medium weather card CSS (z-index and pointer-events), restoring hover and click behavior for the feedback link on affected New Tab Page cards.
• Mike Kaply fixed wallpaper uploads failing when the wallpaper list can’t be queried from remote settings by adding a remote‑settings query fallback/local cache and defensive error handling so users can upload custom wallpapers during remote‑settings outages or timeouts.
• japandi added the widgets.clocks.interaction pref and wired interaction tracking so World Clocks now emits telemetry/events for taps and opens (pref registration + tracker hooks), enabling accurate UX metrics without changing visible UI behavior.
• Maxx Crawford prevented the weather widget from activating without user opt‑in by gating activation on the opt‑in pref and updating the onboarding flow, so weather and related location/telemetry remain disabled by default until explicit user consent.
• Irene Ni made the New Tab client request layouts from remote-settings so NTP layouts and remote-config-driven content now update on load instead of remaining stale; this fixes cases where layout changes pushed via the remote-settings service (layouts collection) weren’t applied, improving consistency on desktop and Android clients that rely on remote layouts.
• Nirmal Advani removed three unused activity-stream preferences (discoverystream.thumbsUpDown.*) from prefs and related code paths, reducing prefs surface area and avoiding confusion in about:config/telemetry without changing user-visible behavior.
• Mike Conley fixed ExternalComponentWrapper to forward “live” properties like isIntersecting from MessageWrapper, restoring correct IntersectionObserver-driven behavior (visibility-based lazy-load and impression tracking) for remote components in the New Tab Page and discovery streams that relied on isIntersecting for render/telemetry triggers.
• Irene Ni standardized New Tab widgets and sections header spacing (standardize spacing) to remove misaligned tiles and reduce visual jitter when resizing or toggling sections in the New Tab Page.
• Mike Conley removed version-153 train-hop compatibility shims for the World Cup newtab logo variations (remove compatibility shims), an internal cleanup that prevents legacy logo-selection fallbacks from influencing current logo variations.
• Maxx Crawford exposed available browser themes to New Tab and added apply/install actions (expose and apply themes), allowing users to install or immediately apply themes from the New Tab surface via ThemeManager/Theme API hooks.
• Maxx Crawford added New Tab Customize Panel browser theme selection strings (add theme selection strings) so the new theme-selection UI is localized and displays correct labels across locales.
• Maxx Crawford added a full browser theme selection sub-panel to the New Tab Customize Panel (theme selection sub-panel) to let users browse, preview, and pick themes directly inside the New Tab customization flow.
• Scott Downe fixed Custom newtab wallpapers flash / blink some seconds after loading newtab by ensuring the custom wallpaper is painted only after image data is ready, which removes the multi-second visual flash on about:newtab for users with custom backgrounds and improves perceived stability during initial new-tab load.
• Maxx Crawford exposed trainhopConfig values in Discovery Stream Admin tooling, giving operators direct access to trainhop routing/weight values from the admin UI/API so content trains and experiment routing can be adjusted without code deploys—this has no immediate end-user UI change but reduces time-to-rollout for Discovery Stream content changes.
• Dre fixed Newtab custom wallpapers flash when selecting from picture of the day widget by deferring the wallpaper swap until the selected Picture of the Day is decoded and ready, which prevents the transient blank/flash users saw when changing wallpapers via the widget and makes wallpaper selection feel instantaneous and stable.
• Maxx Crawford used the POTD thumbnailUrl image for the widget background (instead of the high-res image), which reduces bandwidth, memory footprint, and New Tab Page widget load latency for users who see the Picture‑of‑the‑Day widget.
• Kyle Jones added MAC support to TopSitesFeed when fetching tiles from MARS, which enforces authenticated tile retrieval and reduces missing/401 tile failures for users relying on MARS‑served Top Sites tiles.

Performance Tools (aka Firefox Profiler)

• Bug 2050028 – Enable the Gecko profiler by default with low-overhead features when running mochitests landed, which means mochitest failures now upload profiles by default:
  • 
  • https://tests.firefox.dev/try.html can give you a prompt to ask an AI agent to look at the profile for you using profiler-cli:
    • 

Search and Urlbar

• Dao and Moritz continue work on MCAB working on making the address bar’s contents to be content-process-safe and preparing to allow cross-process IPC for the address bar.
• Mike Kaply fixed hidden actions still visible in Quick Actions mode.
• Daisuke and Drew continued work on supporting Nova on the address bar and search bar components.
• Caleb continued work to use array–binding for places sql queries, to improve performance.

Highlights

• The profile backup mechanism has been enabled by default for all desktop platforms in Nightly, as well as Beta! The current plan is to have this ride out to Firefox 151 for Windows, macOS and Linux on May 18th!
  • This feature, when enabled, will create a copy of your profile data in the background and store it in a single file on your file system that you can restore from.
  • You will be able to manage this feature in Settings under Sync (for now)
    • 
  • You can read more about the feature here
• As followups to the recent addition to the WebExtension tabs API to support the new SplitView tabs feature, tabs.group() and tabs.ungroup() have been fixed to work correctly with split view tabs, and fixed split views being prepended instead of appended to tab groups when adopted into a new window – Bug 2029099 / Bug 2029534
• Adaptive autofill has been enabled on Nightly.
  • Previously, autofill only completed domains (e.g. typing red autofilled reddit.com). Now it can also complete full URLs for pages you visit often (e.g. red → reddit.com/r/firefox), learning from what you actually click in the address bar. If a suggestion isn’t helpful, you can now dismiss it so autofill learns what not to show you too.
    • If you run into issues or have feedback, you can file a bug here!
• Markus Stange [:mstange] implemented dynamic toolbar on top in RDM (#1978145), but also implemented some static skeleton UI so it’s closer to what we actually have in Firefox for Android
  • dynamic toolbar is behind a pref: devtools.responsive.dynamicToolbar.enabled
  • it can be put on top by setting devtools.responsive.dynamicToolbar.onTop, otherwise it’s at the bottom
  • 

Friends of the Firefox team

Resolved bugs (excluding employees)

Script to find new contributors from bug list

Volunteers that fixed more than one bug

• Amin Amir
• aoia7rz7l
• Chukwuka Rosemary
• DrSeed
• Frédéric Wang Nélar
• japandi
• John Iweh
• jonathancabera
• Josh Aas
• Keji Bakare
• kofoworola shonuyi
• konyhéa
• liz
• Mathew Hodson
• Okhuomon Ajayi
• Oluwatobi
• ROSHAAN
• Sam Johnson

New contributors (🌟 = first patch)

•  Anthony Mclamb: Disable the legacy Edge migrator
•  Amin Amir
  • 🌟Fix browsingContext.sys.mjs to assign to #contextCreatedHandled instead of contextCreatedHandled
  • Fix missing WITHOUT ROWID SQLite performance optimization in SERPCategorization.sys.mjs
  • 🌟 Amine Zroual: Omitted maxResults property not handled correctly in getRecentlyClosed
• any1here: install_sig_alt_stack incorrectly checks mmap’s return value
• 🌟 Armin Ulrich: Fix MessageHandlerRegistry.sys.mjs calling getExistingMessageHandler with an unused second argument
• japandi
  • Cannot remove amazon.com from top sites list
  • The height of the pinned tabs area should be responsive to the number of pins
  • Use cenum for nsIHelperAppLauncherDialog reason constants to enable better typescript annotations
• Nathan Johnson [:narjoDev]: Remove browser.display.use_system_colors pref
• DrSeed
  • Firefox shows vertical tabs in new windows despite “Hide tabs and sidebar” setting
  • The “Expand sidebar on hover” option is not kept after the vertical tabs are disabled and enabled again
• Keji Bakare:
  • Split view’s focus-outline is clipped on the right side of left tab
  • White space on the right side of left panel in split view
• 🌟 gotyaoi: Reload toolbar button is active on about:newtab
• Itoro James: [A11y][Keyboard Navigation]Cancelling a note via Keyboard Navigation still saves it
• John Iweh: The notification dot is not displayed if the tab is in a Split View
• 🌟 John Iweh: sidebar-shown attribute remains when sidebar.revamp is false
• 🌟 jonathancabera:
  • The Move tab to Split View option is also displayed for the tabs that are within the Split View
  • A Note with long text (1003 characters) is saved by pressing ENTER even if the “Save” button is disabled
  • Tab group guide line becomes disconnected under certain conditions related to split views in vertical tab mode
• Aloys: Remove logic that forces distribution language packs to be reinstalled when upgrading from Firefoxes older than 67
• liz:
  • Create test to ensure maxRenderCountEstimate is never being set to Infinity in virtual-list component in Fx View
  • Button accessible name does not convey its function: missing topic context (Settings dialog > Topics dialog > buttons Following/Unfollow/Blocked/Unblock)
• Mary cathline: Tab Group Label does not respect touch density in vertical tab bar
• 🌟 Brandon Lucier: Popups opened with window.open give window type normal instead of popup
• karan68: [dialog] New Shortcut dialog needs a label/accessible name
• 🌟 Vector: Button does not programmatically indicate that it opens a dialog (Recent activity section > story card > ••• disclosure > Delete from History button)
• 🌟 Osoble: Update font size and weight for synced tabs device name headers in Firefox View
• konyhéa:
  • Add test for sync admin disabled to browser_syncedtabs_errors_firefoxview.js
  • Check all second paramaters for TestUtils.waitForCondition in Fx View test files
  • Recently Closed Tabs, Tabs from Other Devices, and History pages should have Cmd / Ctrl + Click on a link open the link in the new background tab.
• Noble Chinonso: #shouldHandleEvent in SidebarTreeView.js compares event.keyCode to string values, causing Home/End keys to never be handled
• Pranjali Srivastava: Add a test to verify that the space above tabs is consistent across PB, LWT and sizemode (where appropriate)
• Okhuomon Ajayi:
  • More spacing is needed between the tab note icon and the close icon on the tab
  • The tabs in vertical mode collapsed state are positioned differently in Split View
  • Keep vertical split view tabs stacked vertically even when the sidebar is expanded when expand on hover is enabled
  • Vertical split view tabs can be too big or small when tabs are overflowing
• 🌟 Rishan: Fix duplicated arrow function in browser_history_sidebar.js
• Chukwuka Rosemary:
  • “Forget About This Site” context menu option missing from Firefox View history
  • Long strings are not displayed properly on the about:opentabs page search filed
  • Add test for Forget This Site option in Fxview history context menu.
• ROSHAAN:
  • 🌟Tab note background colour is incorrect for default light theme
  •  [win/linux] The splitter between content areas does not match Figma spec
  • Fix typo in OpenInTabsUtils.confirmOpenInTabs()
• Sameeksha: Disclosure button expanded/collapsed state not programmatically defined (Customize button)
• kofoworola shonuyi:
  • 🌟Actually hide or remove sidebar-shown attribute when in fullscreen.
  • Add a test for checking sidebar-shown attribute in fullscreen mode
• 🌟 Sayd Mateen: Page URL is displayed as tab name when page’s contains about:reader?</a></p> <p>

• Oluwatobi:
  • Unable to delete selected history entries from sidebar
  • Incorrect Sidebar button state/tooltip hover text
  • The city name heading level doesn’t follow the correct heading level order
• Nishchay [:nish]: Unable to add tabs to old closed tab groups (tabGroupState.splitViews is undefined)

 

Project Updates

Add-ons / Web Extensions

Addon Manager & about:addons

• In preparation for the Project Nova restyling of the about:addons page, we have refactored about:addons into separate per-component ES modules, splitting the monolithic aboutaddons.js and aboutaddons.html into 16 dedicated component files under components/ (with no behavior or UI changes) – Bug 2032014
  • NOTE: if you have working on patches with changes to about:addons internals it is very likely you’ll need to rebase and solve merge conflicts hit on top of this refactoring, the internals are still largely the same as before but don’t hesitate to reach out to the Addons team if you have doubts / questions or need help to figure out how to adapt your patch of top of these changes

WebExtensions Framework

• Fixed exportFunction to preserve the constructibility of the wrapped function instead of unconditionally making all exported functions implicitly as constructors – Bug 2033173
  • Thanks to Gregory Pappas for contributing this improvement to the Content Scripts’ Xray Wrappers helpers!
• Fixed a Firefox 151 regression where extension content scripts accessing location.ancestorOrigins caused subsequent page script reads of the same property to fail with “Permission denied”, breaking sites like Gmail – Bug 2034329
  • Thanks to Simon Farre for promptly investigating and fixing this recent regression!

WebExtension APIs

• Updated sessions.getRecentlyClosed() to remove the hardcoded cap when maxResults is omitted – Bug 1392125
  • Shoutout to Amine Zroual for contributing this enhancement to the sessions WebExtensions API!

DevTools

• Artem Manushenkov fixed an issue where autosuggestion popup was removing overridden indicators from properties in the Inspector (#1983408)
• Andrea Marchesini [:baku] fix DevTools cookie header serialization for long cookies, which could lead to cookies not being visible in Netmonitor (#2031299)
• Julian Descottes [:jdescottes] fixed a toolbox crash that was happening we couldn’t find a localization file (e.g. when using a language pack on Nightly) (#2028930)
• Nicolas Chevobbe [:nchevobbe] improved @container tooltip so it show the value of variables used in style()(#2030239), has enough contrast in dark mode (#2033782) and contains a link to select the container (#2031688)
  • 
• Hubert Boma Manilla (:bomsy) is making good progress on migrating the Console to CodeMirror 6 (#2032758, #2026569)

Fluent

• We’re now at over 72% of our strings being Fluent! Got a component still using .properties? Convert when you can!
• 

Migration Improvements

• Thanks to dao for fixing a recent alignment issue in the migration wizard dropdown
• Thanks to volunteer contributor Anthony Mclamb for his patch that disables the legacy EdgeHTML Edge migrator! Once that finishes rolling out, presuming no surprises, we’ll go ahead and remove the migrator entirely.

New Tab Page

• Nova for New Tab has ridden the trains to Beta! It will be enabled by default, globally, when Firefox 151 goes out to release on May 19th
  • It’s possible that we’ll do a train-hop coupled with an experiment to enable HNT Nova for a few clients a bit earlier.
• Maxx Crawford enabled Nova designs for New Tab, rolling out the updated layout, widgets, and customization panel behind HNT Nova flags.
• Maxx Crawford fixed the Nova content feed to render the intended four‑column layout by correcting CSS grid breakpoints.
• Maxx Crawford resolved a first‑load failure in the Weather widget by fixing init order and fetch timing, eliminating the “Oops” error.
• Maxx Crawford synchronized the Weather toggle between about:preferences#home and the panel via the shared showWeather pref to prevent desync.
• Maxx Crawford updated Nova grid focus order to align tab flow with visual order for keyboard users.
• Maxx Crawford fixed critical UI issues in Lists and Timer widgets covering overflow, controls, and layout stability.
• Maxx Crawford guarded document.dir access in Nova render paths to avoid startup cache worker errors and improve startup stability.
• Rolf added a new normalization method for the inferred interest vector to stabilize topic relevance across sessions.
• Rolf prevented unnecessary content refreshes during Pocket New Tab experiments, reducing jank and bandwidth.
• Sameeksha defined the Customize button’s expanded/collapsed state programmatically using aria-expanded for better a11y.
• liz clarified follow/unfollow/blocked button names with topic context so screen readers announce clear actions.
• Vector marked the Delete from History control as opening a dialog via aria-haspopup=dialog for assistive tech.
• Scott Downe fixed a regression that flipped the Wallpapers pref off, restoring user selections.
• Irene Ni corrected privacy link color and focus styles for contrast and keyboard visibility.
• Reem Hamoui added a wallpaper toggle reset in the Nova customization panel so users can quickly restore default wallpapers without extra steps.
• Reem Hamoui fixed the Customize pencil button to match the Nova spec, aligning placement and iconography for visual consistency.
• Dre updated the ‘Fresh new’ wallpapers copy to a clearer, localized message for better comprehension.
• Irene Ni fixed Nova privacy link color and focus styles to meet contrast and focus ring guidelines, improving accessibility on New Tab.
• Irene Ni adjusted Sponsored tile character limits to prevent truncation/overflow, yielding cleaner titles across grid and wide tiles.
• Scott Downe fixed a regression that flipped the Wallpapers user pref to false, restoring wallpapers for affected users and preventing unintended disablement.
• Reem Hamoui hooked the wallpaper check into the new toggle logic so the Customization Panel accurately reflects wallpaper availability and state.
• Irene Ni landed Nova UI updates for the Daily Briefing 3-pack card, improving spacing, type scale, and tap targets.
• Reem Hamoui added a wallpaper toggle reset in the Nova customization panel so users can quickly restore default wallpapers without extra steps.
• Reem Hamoui fixed the Customize pencil button to match the Nova spec, aligning placement and iconography for visual consistency.
• Dre updated the ‘Fresh new’ wallpapers copy to a clearer, localized message for better comprehension.
• Irene Ni fixed Nova privacy link color and focus styles to meet contrast and focus ring guidelines, improving accessibility on New Tab.
• Irene Ni adjusted Sponsored tile character limits to prevent truncation/overflow, yielding cleaner titles across grid and wide tiles.
• Scott Downe fixed a regression that flipped the Wallpapers user pref to false, restoring wallpapers for affected users and preventing unintended disablement.
• Reem Hamoui hooked the wallpaper check into the new toggle logic so the Customization Panel accurately reflects wallpaper availability and state.
• Irene Ni landed Nova UI updates for the Daily Briefing 3-pack card, improving spacing, type scale, and tap targets.

Search and Urlbar

• Marco has fixed a couple of issues with the places databases to try and improve stability. This should help with avoiding users losing bookmarks or favicons.
• Work continues on the new separate search bar to improve the functionality, e.g. allowing middle click to perform a search in a new tab, avoiding performing a search when adding a search engine.
• Work also continues on the new Nova layouts.

Smart Window

• uplifted 10 bugs to 150.0.1 dot release addressing initial user feedback from diary study and Connect
  • jump to bottom of conversation 2028692
  • stop streaming button 2029204
  • back/forward navigation from assistant 2029229
  • dark mode for various chips 2024499
• search engine switching from smart bar 2021973
• Nova styling within smart window 2026794

Storybook/Reusable Components/Acorn Design System

• Dustin converted moz-breadcrumb-group variables into JSON design tokens Bug 2029181 – Convert moz-breadcrumb-group variables into JSON design tokens
• Dustin converted moz-box-* variables into JSON design tokens Bug 2029180 – Convert moz-box-* variables into JSON design tokens
• Dustin converted moz-promo variables to JSON design tokens Bug 2029190 – Convert moz-promo variables into JSON design tokens
• Dustin converted moz-reorderable-list variables to JSON design tokens Bug 2029191 – Convert moz-reorderable-list variables into JSON design tokens
• Dustin converted moz-visual-picker variables to JSON design tokens Bug 2029193 – Convert moz-visual-picker-item variables into JSON design tokens
• Dustin updated browser-shared.css so it passes use-design-tokens Bug 2022985 – Update browser-shared.css so it passes use-design-tokens
• Dustin updated popup.css so it passes use-design-tokens Bug 2022979 – Update popup.css so it passes use-design-tokens
• Jon added opacity tokens and added opacity to use-design-tokens stylelint rule  Bug 1955325 – Create opacity tokens
• Jon converted toolbar design tokens to JSON Bug 2017970 – Convert toolbar design tokens to json
• Anna fixed moz-select with panel-list drop-down size inconsistency Bug 2032365 – Applications Action drop-down menus sometimes have a different size when opened
• Anna fixed issue with the disabled state of moz-radio component Bug 2027123 – moz-radio disabled state cannot be changed while the moz-radio-group is disabled
• Anna updated moz-button and moz-box-button components to prevent label corruption when accesskeys are present and the label changes.   Bug 2022326 – moz-button with accesskey label becomes corrupted when l10nId updates dynamically

UX Fundamentals

• The error pages shown when a server sends back an invalid response header or an unsupported content encoding now display accurate, context-specific messages. The invalid response header page also gained a helpful list of next steps. – 2027209
• In progress: The error page illustrations are being replaced with new artwork, and the system now supports per-illustration size configuration, giving each image the ability to define its own appropriate dimensions. – 2031837

Settings Redesign

• Tim converted settings related to Accessibility page to config-based pane Bug 1968116 – Convert settings related to Accessibility page to config-based settings
• Benjamin converted Privacy & Security page to the config-based pane Bug 1968112 – Convert settings related to Privacy & Security page to config-based settings
• Finn integrated Firefox Labs page into setting-pane config Bug 2021047 – Integrate Firefox Labs page into setting-pane config
• Anna converted Firefox Updates section to config-based prefs Bug 1990961 – Convert Firefox Updates section to config-based prefs
• Mark Kennedy added moz-promo, that is welcoming users to the redesigned settings Bug 2015093 – Add a moz-promo to welcome users to the redesign
  • 
• Anna added possibility to search for actions in the redesigned “Applications” section Bug 2020370 – It’s no longer possible to search for actions in the new “Applications” section
• Anna fixed the Settings navbar layout breakage

Highlights

• Thanks to overholt, macOS Nightly now has support for sharing the current tab’s URL via QR Code (Right-click tab, Share > Generate QR Code). This is held to Nightly for now.
  • 
• Scott Downe fixed an issue where newtab background GIFs could max out RAM while idle in the background by throttling animated background decoding on backgrounded tabs. This fix is going out in Firefox 150.
• Special thanks to volunteer contributor 1justinpeter who just added speed unit conversion support to the AwesomeBar!
  • You can try it in Nightly – try 1000 km/h to m/s
    • 
  • This is tentatively slated to go out in Firefox 150
• New Tab Sections have been enabled by default in Canada!
  • 

Friends of the Firefox team

Resolved bugs (excluding employees)

Volunteers that fixed more than one bug

• Chris Vander Linden
• Itiel
• Justin Peter
• Khalid AlHaddad
• Mauro V [:cheff]
• Sam Johnson
• Sebastian Zartner [:sebo]

New contributors (🌟 = first patch)

•  Mohammed Abdullah: screenshot command crops image after 10000px height
•  Jocsan: Profile delete page title should enclose profile name in quotes
• 🌟 karan68: [dialog] ‘X’ icon buttons are missing labels
•  Knot False: Replace KeywordUtils use of nsIScriptableUnicodeConverter with Services.textToSubURI.ConvertAndEscape
• 🌟 Pushkar Singh: Remove unused devtools.inspector.remote pref
• 🌟 MUTHUSRIHEMADHARSHINI: Card images do not have an alt attribute
•  Sukhmeet[:sukh]: firefox forgets open tabs depending on window close order
• 🌟 Alex Reisner: Create a preference to disable the drag-and-drop method of creating tab groups
• 🌟 torrenceb90: Remove unused devtools.target-switching.server.enabled pref
• 🌟 baris: Button does not programmatically indicate that it opens a dialog (Customize button)

Project Updates

Add-ons / Web Extensions

WebExtensions Framework

• Fixed a structuredClone regression in the MV2 userScripts sandbox, bringing it in line with the fix already applied to content scripts and MV3 userScripts sandboxes, fix applied in Nightly 150 and uplifted to Beta 149 – Bug 2020773
• Fixed a tab crash triggered by calling Document.parseHTMLUnsafe() from a browser extension content script (due to an assertion failure hit because parseHTMLUnsafe was wrongly trying to create a document that belongs to the expanded privileged principal that originated the call). The changes applied is now making sure parseHTMLUnsafe will use the webpage document’s principal (and prevent the crash as a side effect of that) – Bug 1912587
• Fixed a regression where the load event on about:blank iframes would not fire when a content script injected a style element (regressed in Firefox 148 as a side effect of the changes applied by Bug 543435, fix landed in Nightly 140 and uplifted to Beta 149 and Release 148) – Bug 2020300
  • Thanks to Vincent Villa for promptly investigating and fixing this regression!

WebExtension APIs

• As part of followups related to the work to allow action.openPopup calls without user activation, action.openPopup() will reject the requests when another panel, context menu, doorhanger, or notification is already open in the window – Bug 2022281
• As part of followups to the work in support of the splitView mode support introduced in the tabs API, tabs.move() has been tweaked to correctly return all specified tabs moved in a split view – Bug 2022372

Addon Manager & about:addons

• Fixed a rendering regression where the context menu on about:addons cards would appear with a transparent background at non-default zoom levels – Bug 2006926
  • Thanks to Botond Ballo for investigating and fixing this small rendering regression!

DevTools

• Chris Vander Linden moved the SearchInFileBar component to a shared folder in (#2019256, #2020518)
• Chris Vander Linden made a few Netmonitor file use proper private properties (#2021639, #2021640, #2021641, #2021642, #2021643, #2021644, #2021645)
• Mohammed Abdullah refactored screenshot dimension handling to use shared logic from ScreenshotsUtils.sys.mjs (#1942439)
• Lorenz A fixed an issue in the Flexbox Layout pane regarding base size when flex-basis was set from the flex shorthand (#1939289)
• Oriol Brufau [:Oriol] improved one of our object test (#2021445)
• Sebastian Zartner [:sebo] added a new Element-specific pseudo-classes section in the pseudo-class panel and added support for the new :open pseudo class (#2014442)
  • 
• Simon Farre [:sfarre] made it so Reporting API requests are now visible in Netmonitor (#2013043)
• Leo McArdle [:leo] fixed the Network request panel so it would show POST data even before the request was finished (#2014623)
• Leo McArdle [:leo] fixed a couple issues with the Inspector Fonts panel inputs (#2013910, #2013904)
• Julian Descottes [:jdescottes] updated the device list in Responsive Device Mode to include recent phones and tablets (#1982802)

WebDriver

• Khalid AlHaddad contributed over the past two weeks by adding a test for correct viewport dimensions on new top-level browsing contexts, improving WebDriver tests with global asyncio markers and a timeout multiplier for a better stability of slow running builds, and introducing a fixture to remove webextensions installed during a test. Thank’s a lot!
• James Teh added Marionette-prefixed commands to query extended accessibility properties and traverse the accessibility tree using UUID-identified nodes.
• Jonathan Moss updated the marionette-integration test manifest files so all tests now run as part of the OS integration CI jobs.
• Alexandra Borovova fixed a regression when prompts opened with WebDriver Classic were automatically closed by default when the `moz:debuggerAddress` capability was passed, which is still a common pattern for Selenium.
• Alexandra Borovova fixed the download events that were triggered by the requests with the `Content-Dispostion` header opened in the new tab to be linked to a navigation.
• Alexandra Borovova updated the logic to not send the “log.entryAdded” events for console APIs that don’t use the printer (e.g., `console.time` or `console.clear`).
• Henrik Skupin fixed an issue in the browsingContext.locateNodes command where the root element was not returned when using a CSS selector.
• Henrik Skupin simplified the logic for Marionette commands managing window state, size, and position to improve stability.
• Julian Descottes fixed the support of non-utf8 headers for various network module commands.
• Julian Descottes fixed a bug with keepalive requests which could still be sent after setting the network conditions to “offline”.
• Julian Descottes fixed a race condition which could lead parallel calls to browsingContext.setViewport to timeout.

Lint, Docs and Workflow

• Mossop has replaced most instances of ContentTask.spawn with SpecialPowers.spawn.
  • There is a lint rule to prevent further uses.
  • Feel free to help clean up existing uses if you have any.
• https://arewemozsrcyet.com/ is live and in the middle of being moved to a mozilla repo, bugs / comments can go to https://bugzilla.mozilla.org/show_bug.cgi?id=2014746
  • 

New Tab Page

• Luca Greco fixed an issue where the new tab page was broken for users who had moved their profile to a new directory. Special shout-out to Scott for driving that one over the line and getting the fix uplifted to Beta!
• baris updated a button so that it indicated that it opens a dialog (Customize button) by adding aria-haspopup=”dialog” and focus management so screen readers announce the Personalize dialog correctly.
• Maxx Crawford added the first version of a refined grid system for Nova, introducing column-based container queries and CSS tokens for more consistent responsive New Tab layouts. This is currently off by default.
• Maxx Crawford updated Widgets components to use parent grid columns so cards align to the new Nova grid across breakpoints without layout jumps.
• Mike Conley enabled the pref to communicate with MARS over OHTTP by default so New Tab network calls use OHTTP by default, reducing IP exposure for all channels. This was already enabled on Beta and Release via Nimbus, but this patch is the pref flip that will ride the trains.
• Mike Conley added a train-hoppable asrouter-newtab-message external component for inline messaging to let us update New Tab inline messages via Remote Settings without a full Firefox update. The OMC team will take over building out the actual UI for the new message surface.
• Nathan Barrett landed sections layout support for Nova, to refine section spacing and ordering using the new grid for a cleaner, denser above-the-fold.
• Maxx Crawford fixed “Weather data is not available right now message” begin shown on the Weather widget by correcting gating so the Weather widget fetches and renders data reliably on v150.
• Maxx Crawford resolved an issue where experiments could accidentally override weather preferences set by the user
• Nina Pypchenko [:nina-py] aligned the newtab devtools button to match the Personalize button to improve visual consistency and discoverability of the DevTools toggle.

Search

• Marco worked on replacing ContentTask.spawn in various tests @ 2023131, 2023134
• Dale worked on several TrustPanel UX fixes @ 2017369, 2017376
• Daisuke fixed issue with SwitchTab results with no title @ 2020341
• Moritz worked on several telemetry issues relating to the new search bar 2021927
• Moritz fixed the unified search button having no focus border @ 2023656
• Dao added support for middle clicking to search in the unified search menu @ 2011220

Smart Window

• “Beta” badges 2017667
  • 
• Added AI Controls integration, supporting the blocked state (2010599)
  • 
• Added more user choice with split memory generation (2017428)
  • 
• Added chat search in Firefox View (2009070)
• Follow-up prompts now persist across tab switches (2019696)
• Conversation starter prompts now update with the foregrounded tab (2013657)
• Current tab context is now removable (2018802)
• Keyboard fixes for smartbar input (2019556 2017939 2015090)
• Show sign in button in chat if signed out (2015720)

Storybook/Reusable Components/Acorn Design System

• Tim Giles fixed some issues with panel-list using popover:
  • A macOS issue where keyboard events went to the wrong <moz-select>Bug 2017668
  • Scrolling now dismisses an open panel-listBug 2018563
• akulyk updated the panel-list variant of moz-select to use role=”combobox”, improving screen reader semantics and keyboard navigation consistency.
• Dustin Whisman updated the moz- widgets CSS to pass use-design-tokens:
  • panel-list, moz-input-*, moz-select, moz-toggle, moz-visual-picker, moz-message-bar, moz-five-star, and moz-reorderable-list
• Dustin Whisman updated some design token names for consistency (Bug 2013342):
  • –font-size-heading-* now a font-size variant (was –heading-font-size)
  • –card-border-color, –card-box-shadow, –card-box-shadow-hover, –popup-box-shadow, –tab-box-shadow (were nested as variants previously and now are under their component name)

UX Fundamentals

• Added keyboard autofocus to the “Try Again” button in Felt Privacy error pages so users who land on an error page can immediately press enter to retry. (2021447)
• Added keyboard access keys to the three primary error page buttons: G (Go Back), T (Try Again), and P (Proceed to Site). (404501)
• In progress: refactoring net error illustrations into a shared object and adding alt text so assistive technology can read out meaningful descriptions. (2022033)
• In progress: adding improved messaging to the file-not-found error page. (2018850)
• In progress: restoring the error page for Work Offline mode so users see messaging that accurately reflects that they’re in Offline mode, not that there’s a network problem. (