Microsoft Edge 142 web platform release notes (Oct. 2025) (#3573)

* New beta web platform release notes

* Finalized relnotes content

* In-article TOC

* Fix md tagging

* Writer/Editor pass

* sdk expect dates

* New beta web platform release notes

* Writer/Editor pass, format

* toc entry

* linkfix

* Edit pass for new features

* OTs

* escape length

* Writer/Editor review pass

* New beta web platform release notes

* Sort features and clean them up

* More formatting

* cont'd

* webrtc audiolevel

* cont'd

* cont'd

* browser bound keys

* Done with most content

* toc

* add todo's for clarif

* see also todos

* links

* Revert "links"

This reverts commit e456df6.

* addressed todos

* nits

* link

* fix date

* cap'z JS

* New beta web platform release notes

* Add TOC entry

* In progress rewrite and formatting

* Done with content changes

* detailed content

* escape code in link text

* Remove local network access as it's not shipping in 140

* Writer/Editor pass

* linkfix

* New beta web platform release notes

* toc, some cleanup

* technical editing of 141 items

* detailed content

* fix link

* finished writer/editor pass

* likely date

* Address comments

* Clarified syntax

* New beta web platform release notes

* toc, Oct. 4x

* Edited CSS features

* Remove 141 feature

* web apis

* OTs

* Change script to include more Chrome OTs

* writer/editor pass

* del future date: yaml, esc HTML tags in link text

* try empty date: yaml field

* date:

* new, or active OTs?

* Re-order OT section

---------

Co-authored-by: captainbrosset <[email protected]>
Co-authored-by: Michael S. Hoffman <[email protected]>
Co-authored-by: Michael Hoffman <[email protected]>

Author: captainbrosset

microsoft-edge/toc.yml

@@ -30,6 +30,10 @@
           href: ./web-platform/release-notes/index.md
           displayName: what's new, announcements
 
+        - name: Microsoft Edge 142
+          href: ./web-platform/release-notes/142.md
+          displayName: Microsoft Edge 142 web platform release notes (Oct. 2025)  # page title
+
         - name: Microsoft Edge 141
           href: ./web-platform/release-notes/141.md
           displayName: Microsoft Edge 141 web platform release notes (Oct. 2025)  # page title

microsoft-edge/web-platform/release-notes/135.md

@@ -39,7 +39,6 @@ To stay up-to-date and get the latest web platform features, download a preview
     * [Create service worker client and inherit service worker controller for iframe with `srcdoc`](#create-service-worker-client-and-inherit-service-worker-controller-for-iframe-with-srcdoc)
     * [Dispatching click events to captured pointer](#dispatching-click-events-to-captured-pointer)
     * [Float16Array](#float16array)
-    * [HSTS tracking prevention](#hsts-tracking-prevention)
     * [`sourceElement` property for `NavigateEvent`](#sourceelement-property-for-navigateevent)
     * [PerformanceNavigationTiming API NotRestoredReasons name change](#performancenavigationtiming-api-notrestoredreasons-name-change)
     * [Observable API](#observable-api)
@@ -244,14 +243,6 @@ If a pointer is captured while the `pointerup` event is being dispatched, the `c
 The `Float16Array` typed array is now supported.  Number values are rounded to half-precision float-point format (IEEE FP16) when writing into a `Float16Array` instance.
 
 
-<!-- ---------- -->
-###### HSTS tracking prevention
-
-Mitigates user tracking by third-parties via the HTTP Strict Transport Security (HSTS) cache.
-
-This feature only allows HSTS upgrades for top-level navigations, and blocks HSTS upgrades for sub-resource requests.  Blocking such an HSTS upgrade makes it infeasible for third-party sites to use the HSTS cache in order to track a user across the web.
-
-
 <!-- ---------- -->
 ###### `sourceElement` property for `NavigateEvent`
 

microsoft-edge/web-platform/release-notes/139.md

@@ -37,7 +37,6 @@ To stay up-to-date and get the latest web platform features, download a preview
     * [WebGPU: 3D texture support for BC and ASTC compressed formats](#webgpu-3d-texture-support-for-bc-and-astc-compressed-formats)
     * [WebXR depth sensing performance improvements](#webxr-depth-sensing-performance-improvements)
   * [PWA features](#pwa-features)
-    * [New PWA manifest update algorithm](#new-pwa-manifest-update-algorithm)
     * [Web app scope extensions](#web-app-scope-extensions)
   * [Removed features](#removed-features)
     * [Remove auto-detection of ISO-2022-JP charset in HTML](#remove-auto-detection-of-iso-2022-jp-charset-in-html)
@@ -285,23 +284,6 @@ See also:
 #### PWA features
 
 
-<!-- ---------- -->
-###### New PWA manifest update algorithm
-
-The updating of installed PWAs uses a new algorithm.  The new update algorithm makes the update process more deterministic and predictable, and gives you more control over whether, and when, updates should apply to existing installations of your app.
-
-The new update algorithm has the following benefits:
-
-* **Consistency:** The algorithm provides a consistent way to detect when a manifest update should happen.
-* **Reduced user interruptions:** App users won't see the update dialog, except when it's strictly necessary, such as to confirm security-sensitive changes.
-* **Browser flexibility:** Microsoft Edge can now allow known, trusted apps to update without displaying a notification, and can block updates for known bad apps.
-* **Developer control:** You have more control over when the update dialog is shown to users.
-* **Reduce network traffic:** Unnecessary network traffic is minimized.
-
-See also:
-* [Predictable Web App Updating - Explainer](https://github.com/WICG/manifest-incubations/blob/gh-pages/predictable-app-updating.md)
-
-
 <!-- ---------- -->
 ###### Web app scope extensions
 

microsoft-edge/web-platform/release-notes/140.md

@@ -27,9 +27,6 @@ To stay up-to-date and get the latest web platform features, download a preview
     * [View transitions: more animation properties are inherited](#view-transitions-more-animation-properties-are-inherited)
     * [Nested view transitions](#nested-view-transitions)
     * [`font-variation-settings` descriptor in `@font-face` rules](#font-variation-settings-descriptor-in-font-face-rules)
-  * [SVG features](#svg-features)
-    * [CSS `width` and `height` support for SVG `<use>` element](#css-width-and-height-support-for-svg-use-element)
-    * [Support `download` attribute in SVG `<a>` element](#support-download-attribute-in-svg-a-element)
   * [Web APIs](#web-apis)
     * [`__Http-` and `__HostHttp-` cookie name prefixes](#__http--and-__hosthttp--cookie-name-prefixes)
     * [`overscroll-behavior` propagation from `<html>` to the viewport](#overscroll-behavior-propagation-from-html-to-the-viewport)
@@ -214,56 +211,6 @@ See also:
 * [@font-face](https://developer.mozilla.org/docs/Web/CSS/@font-face) at MDN.
 
 
-<!-- ------------------------------ -->
-#### SVG features
-
-
-<!-- ---------- -->
-###### CSS width and height support for SVG `<use>` element
-
-The SVG `<use>` element now supports the `width` and `height` CSS properties.
-
-This allows you to control the sizing of SVG elements through CSS, such as to improve their responsiveness.
-
-With this feature, the following two HTML snippets now produce the same output:
-
-```html
-<svg width="100px" height="100px">
- <defs>
-    <symbol id="sym" width="80" height="80">
-      <rect width="100" height="100" fill="green" />
-    </symbol>
-  </defs>
-  <use href="#sym" style="width:40px; height:40px" />
-</svg>
-```
-
-```html
-<svg width="100px" height="100px">
- <defs>
-    <symbol id="sym" width="80" height="80">
-      <rect width="100" height="100" fill="green" />
-    </symbol>
-  </defs>
-  <use href="#sym" width="40" height="40" />
-</svg>
-```
-
-See also:
-* [`<svg>`](https://developer.mozilla.org/docs/Web/SVG/Reference/Element/svg) at MDN.
-
-
-<!-- ---------- -->
-###### Support `download` attribute in SVG `<a>` element 
-
-The `download` attribute is now supported by SVG `<a>` elements.
-
-The `download` attribute enables you to specify that the target of an SVG hyperlink should be downloaded rather than navigated to.
-
-See also:
-* [`<a>`](https://developer.mozilla.org/docs/Web/SVG/Reference/Element/a) at MDN.
-
-
 <!-- ------------------------------ -->
 #### Web APIs
 

microsoft-edge/web-platform/release-notes/141.md

@@ -5,10 +5,9 @@ author: MSEdgeTeam
 ms.author: msedgedevrel
 ms.topic: conceptual
 ms.service: microsoft-edge
-ms.date: 09/04/2025
+ms.date: 10/02/2025
 ---
 # Microsoft Edge 141 web platform release notes (Oct. 2025)
-<!-- todo: check date field above -->
 
 The following are the new web platform features and updates in Microsoft Edge 141, which releases on October 2, 2025.
 
@@ -21,11 +20,9 @@ To stay up-to-date and get the latest web platform features, download a preview
 * [Web platform features](#web-platform-features)
   * [CSS features](#css-features)
     * [CSS `::search-text` pseudo-element](#css-search-text-pseudo-element)
-    * [`document.activeViewTransition` property](#documentactiveviewtransition-property)
     * [Support `width` and `height` presentational attributes on nested `<svg>` elements](#support-width-and-height-presentational-attributes-on-nested-svg-elements)
   * [Web APIs](#web-apis)
     * [`ariaNotify()` API](#arianotify-api)
-    * [`dataTransfer` property for `insertFromPaste`, `insertFromDrop`, and `insertReplacementText` input events](#datatransfer-property-for-insertfrompaste-insertfromdrop-and-insertreplacementtext-input-events)
     * [IndexedDB `getAllRecords()` method and `direction` option for `getAll()` and `getAllKeys()`](#indexeddb-getallrecords-method-and-direction-option-for-getall-and-getallkeys)
     * [Navigation API `precommitHandler`](#navigation-api-precommithandler)
     * [`windowAudio` option for `getDisplayMedia()`](#windowaudio-option-for-getdisplaymedia)
@@ -81,24 +78,6 @@ See also:
 * [::search-text](https://drafts.csswg.org/css-pseudo-4/#selectordef-search-text) in _CSS Pseudo-Elements Module Level 4_.
 
 
-<!-- ---------- -->
-###### `document.activeViewTransition` property
-
-The `document.activeViewTransition` property provides access to the currently running view transition, whether this transition is on a single web page, or between two web pages.
-
-The View Transition API allows you to create visual transitions between different states of a single page, or between multiple pages.
-
-For transitions within single pages, the `document.startViewTransition()` method returns a transition object.  The `document.activeViewTransition` property now provides access to this transition object, which means you no longer need to store the `document.startViewTransition()` return value.
-
-For transitions between multiple pages, the `document.activeViewTransition` property now gives you access to the currently running transition object, for the duration of the transition. This is in addition to the `pageswap` and `pagereveal` events.
-
-See also:
-* [View Transition API](https://developer.mozilla.org/docs/Web/API/View_Transition_API) at MDN.
-* [Document: startViewTransition() method](https://developer.mozilla.org/docs/Web/API/Document/startViewTransition) at MDN.
-* [Window: pageswap event](https://developer.mozilla.org/docs/Web/API/Window/pageswap_event) at MDN.
-* [Window: pagereveal event](https://developer.mozilla.org/docs/Web/API/Window/pagereveal_event) at MDN.
-
-
 <!-- ---------- -->
 ###### Support `width` and `height` presentational attributes on nested `<svg>` elements
 
@@ -130,45 +109,6 @@ See also:
 * [`<svg>`](https://developer.mozilla.org/docs/Web/SVG/Reference/Element/svg) at MDN.
 
 
-<!-- ---------- 
-todo: this is planned to ship with 142 after all. Keeping here until we need it for the 142 release notes.
-###### Range syntax for style container queries and `if()` functions
-
-The CSS `@container style()` queries and `if()` functions now support the range syntax.
-
-The range syntax makes it possible to compare custom properties and values by using the `<` and `>` operators.
-
-For a comparison to be valid, both sides of the comparison must resolve to the same data type.  The range syntax is limited to the following numeric types: `<length>`, `<number>`, `<percentage>`, `<angle>`, `<time>`, `<frequency>`, and `<resolution>`.
-
-Example comparing a custom property with a literal length:
-
-```css
-@container style(--inner-padding > 1em) {
-  .card { border: 2px solid; }
-}
-```
-
-Example comparing two literal values:
-
-```css
-@container style(1em < 20px) {
-  ...
-}
-```
-
-Example comparing a value from the `attr()` substitution function with a literal value:
-
-```css
-.item-grid {
-  background-color: if(style(attr(data-columns, type<number>) > 2): lightblue; else: white);
-}
-```
-
-See also:
-* []()
--->
-
-
 <!-- ------------------------------ -->
 #### Web APIs
 
@@ -182,22 +122,6 @@ See also:
 * [Creating a more accessible web with Aria Notify](https://blogs.windows.com/msedgedev/2025/05/05/creating-a-more-accessible-web-with-aria-notify/).
 
 
-<!-- ---------- -->
-###### `dataTransfer` property for `insertFromPaste`, `insertFromDrop`, and `insertReplacementText` input events
-
-The input event objects of type `insertFromPaste`, `insertFromDrop`, and `insertReplacementText` now have a `dataTransfer` property, for better interoperability with other browsers.
-
-The `dataTransfer` property provides access to the clipboard or drag-drop data when the user edits text within a `contenteditable` element.  The same data is also available on the `dataTransfer` property of `beforeinput` events.
-
-This feature only applies to `contenteditable` elements.
-
-See also:
-* [DataTransfer](https://developer.mozilla.org/docs/Web/API/DataTransfer) at MDN.
-* [InputEvent: inputType property](https://developer.mozilla.org/docs/Web/API/InputEvent/inputType) at MDN.
-* [HTML contenteditable global attribute](https://developer.mozilla.org/docs/Web/HTML/Reference/Global_attributes/contenteditable) at MDN.
-* [Element: beforeinput event](https://developer.mozilla.org/docs/Web/API/Element/beforeinput_event) at MDN.
-
-
 <!-- ---------- -->
 ###### IndexedDB `getAllRecords()` method and `direction` option for `getAll()` and `getAllKeys()`