Merge pull request #3658 from MicrosoftDocs/user/pabrosse/select-multiple

`<select>` element UI changes in 142

Author: captainbrosset

microsoft-edge/web-platform/release-notes/142-images/select-dropdown.png

@@ -21,6 +21,8 @@ To stay up-to-date and get the latest web platform features, download a preview
    * [AccentColor and AccentColorText system colors](#accentcolor-and-accentcolortext-system-colors)
    * [document.activeViewTransition property](#documentactiveviewtransition-property)
    * [Range syntax for style container queries and if() functions](#range-syntax-for-style-container-queries-and-if-functions)
+* [UI features](#ui-features)
+   * [Mobile and desktop parity for \<select\> elements](#mobile-and-desktop-parity-for-select-elements)
 * [SVG features](#svg-features)
    * [Support download attribute in SVG \<a\> element](#support-download-attribute-in-svg-a-element)
    * [CSS width and height support for SVG \<use\> element](#css-width-and-height-support-for-svg-use-element)
@@ -133,6 +135,49 @@ See also:
 * [if()](https://developer.mozilla.org/docs/Web/CSS/if) at MDN.
 
 
+<!-- ====================================================================== -->
+## UI features
+
+Below are user interface changes in Microsoft Edge.
+
+
+<!-- ------------------------------ -->
+#### Mobile and desktop parity for `<select>` elements
+
+`<select>` HTML elements, when using the `size` and `multiple` attributes, now appear the same way on desktop and mobile devices, as either:
+
+* A scrollable list showing all options at once in the page.
+* An expandable dropdown list in the page.
+
+
+<!-- ---------- -->
+###### `<select size="3">`
+
+ `<select size="3">` (or another `size` value greater than 1) now always appears as a list showing all options at once in the page, both on desktop and mobile devices:
+
+![A list showing all options at once in the page](./142-images/select-list.png)
+
+Previously, mobile devices ignored the `size` attribute and always rendered an element such as `<select size="3">` as a dropdown list.
+
+
+<!-- ---------- -->
+###### `<select multiple>`
+
+`<select multiple>` now always appears as a list showing all options at once in the page, both on desktop and mobile devices.
+
+Previously, mobile devices rendered `<select multiple>` as a dropdown list.
+
+
+<!-- ---------- -->
+###### `<select multiple size="1">`
+
+`<select multiple size="1">` now always appears as a dropdown list, both on desktop and mobile devices:
+
+![A dropdown list in the page](./142-images/select-dropdown.png)
+
+Previously, desktop devices rendered `<select multiple size="1">` as a list showing all options at once in the page.
+
+
 <!-- ====================================================================== -->
 ## SVG features
 <!-- https://developer.mozilla.org/docs/Web/SVG -->

microsoft-edge/web-platform/release-notes/142-images/select-list.png

@@ -38,6 +38,7 @@ This table lists high-impact changes which the Microsoft Edge team is tracking c
 | Deprecate unload event | Future release (TBD) | Introduces a new Permission-Policy to allow creating unload event listeners. The default policy is `allow`, but the default policy will gradually be migrated to `deny`, such that unload handlers stop firing on pages, unless a page explicitly opts in to re-enable them.  This change is happening in the Chromium project, on which Microsoft Edge is based.  For more information, see [Intent to Deprecate: Deprecate unload event](https://groups.google.com/a/chromium.org/g/blink-dev/c/dvusqw9-IhI/m/SBkm_u1RAQAJ). |
 | Externally loaded entities in XML parsing | v144 | Synchronous fetching of external XML entities/DTDs, which are then used when parsing under specific circumstances, has been removed. See [Externally loaded entities in XML parsing](./release-notes/144.md#externally-loaded-entities-in-xml-parsing), in _Microsoft Edge 144 web platform release notes (Jan. 2025)_. |
 | Deprecate `Intl.Locale` getters | v143 | The accessor properties of the `Intl.Locale` object are now deprecated, in favor of the corresponding functions, per specification. See [Deprecate `Intl.Locale` getters](./release-notes/143.md#deprecate-intllocale-getters), in _Microsoft Edge 143 web platform release notes (Dec. 2025)_. |
+| Mobile and desktop parity for `<select>` elements | v142 | The appearance of `<select>` HTML elements, when using the `multiple` and `size` attributes, is now consistent across mobile and desktop devices. See [Mobile and desktop parity for `<select>` elements](./release-notes/142.md#mobile-and-desktop-parity-for-select-elements), in _Microsoft Edge 142 web platform release notes (Oct. 2025)_. |
 | Remove special font size rules for `<h1>` | v140 | The special margin and font size rules for `<h1>` elements, when nested in `<article>`, `<aside>`, `<nav>`, and `<section>` elements, are now removed, to improve accessibility. See [Removed special font size rules for `<h1>` within some elements](./release-notes/140.md#removed-special-font-size-rules-for-h1-within-some-elements) in _Microsoft Edge 140 web platform release notes (Sep. 2025)_. |
 | Asynchronous range removal for Media Source Extensions throws exceptions | v138 | The following changes have been made to the Media Source Extensions specification, to disallow ambiguously defined behavior involving asynchronous range removals:  <br/>* `SourceBuffer.abort()` no longer aborts `SourceBuffer.remove()` operations.  <br/>* Setting `MediaSource.duration` can no longer truncate currently buffered media.  <br/>While these changes were made a long time ago, and Safari and Firefox have already implemented them, Chromium had not yet done so.  Exceptions are now thrown in both cases.  See [Media Source API](https://developer.mozilla.org/docs/Web/API/Media_Source_Extensions_API) at MDN. |
 | Removal of automatic SwiftShader fallback | v138 | Previously, if a WebGL context could not be created with the available GPU, Chromium would automatically fall back to using the SwiftShader software renderer.  This automatic fallback behavior is now removed and the WebGL context creation will now fail instead of falling back to SwiftShader.  SwiftShader poses security risks and leads to a poor user experience when falling back from a high-performance GPU-backed WebGL to a CPU-backed implementation.  SwiftShader remains a useful tool for doing headless testing on a site.  This use case is still supported by opting in, which you can do by running Microsoft Edge with the `--enable-unsafe-swiftshader` command-line argument.  See [Using Chromium with SwiftShader](https://chromium.googlesource.com/chromium/src/+/main/docs/gpu/swiftshader.md). |