Experimental Chromium Web Platform Features
Experimental web platform features are not yet part of the official web platform specifications and are marked as "experimental" in Chromium.
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Added in Chromium 123 current
- Element Get HTML
ElementGetHTML
chromestatus.comThe prototype implementation (which was shipped in 2020 and then shape-changed in 2023) contained a method called `getInnerHTML()` that could be used to serialize DOM trees containing shadow roots. That part of the prototype was not standardized with the rest of declarative shadow dom, and only recently has it reached spec consensus (https://github.com/whatwg/html/issues/8867). As part of that consensus, the shape of the getInnerHTML API changed. This feature represents the desire to ship the new, agreed-upon shape, which is: - getHTML({serializableShadowRoots:bool, shadowRoots:[roots]}).
- Nested Top Layer Support
NestedTopLayerSupport
chromestatus.comThe prior behavior caused issues if a top layer element (dialog, fullscreen, etc.) was DOM-nested within a popover. The inner element, when promoted to the top layer, would cause the outer popover to be hidden, which also (via CSS display:none) hid the inner element. That, in turn, caused issues at least for dialogs, which inert the entire page. This change makes top layer elements "nestable" within popovers.
- Shadow Root Clonable
ShadowRootClonable
chromestatus.comThis enables individual control over whether a shadow root is clonable (via standard platform cloning commands such as `cloneNode()`). Imperative shadow roots can now be controlled via a parameter to `attachShadow({clonable:true})`. Declarative shadow roots can be controlled via a new attribute, `<template shadowrootmode=open shadowrootclonable>`.
- WebGPU Experimental Features
WebGPUExperimentalFeatures
chromestatus.comFunctionality added to the WebGPU spec after its first shipment in a browser. ServiceWorker and SharedWorker support is added to WebGPU, aligning with existing WebGL capabilities.
- Writing Suggestions
WritingSuggestions
chromestatus.comUAs are starting to provide writing suggestions to users as they type on various editable fields across the web. While this is generally useful for users, there are cases when developers may want to turn off UA-provided writing assistance, such as extensions or sites that wish to provide similar functionality on their own. To that end, developers need a solution that would turn on/off UA-provided writing assistance. The new attribute 'writingsuggestions' has values 'true'/'false' that would allow developers to turn on/off browser-provided writing suggestions. The attribute's state for an element can also be inherited from ancestor elements, thereby allowing developers to control this functionality at a per-element or per-document/sub-document scale.
- New features in Chromium 123 with missing descriptionCSS Calc Size Function
CSSCalcSizeFunction
CSS Custom State New SyntaxCSSCustomStateNewSyntax
CSS Pseudo Open ClosedCSSPseudoOpenClosed
Dialog Close When Open RemovedDialogCloseWhenOpenRemoved
Display Contents FocusableDisplayContentsFocusable
Page Conceal EventPageConcealEvent
Web Assembly JS Promise IntegrationWebAssemblyJSPromiseIntegration
Added in Chromium 122 Polypane 18.0.4
- Form Controls Vertical Writing Mode Direction Support
FormControlsVerticalWritingModeDirectionSupport
chromestatus.comCSS property writing-mode allow elements to go vertical, but users cannot set the direction in which value changes. With this feature, we are allowing the form control elements meter, progress and range input type to have vertical writing mode and choose the form control's value direction. If direction is rtl, the value is rendered from bottom to top. If direction is ltr, the value is rendered from top to bottom. For Web compatibility, we plan to slowly rollout the change in 123 and enable in stable in 124.
- Keyboard Focusable Scrollers
KeyboardFocusableScrollers
chromestatus.comImproves accessibility by making scroll containers focusable using sequential focus navigation. Today, the tab key doesn't focus scrollers unless tabIndex is explicitly set to 0 or more. By making scrollers focusable by default, users who can't (or don't want to) use a mouse will be able to focus clipped content using a keyboard's tab and arrow keys. This behavior is enabled only if the scroller does not contain any keyboard focusable children. This logic is necessary so we don't cause regressions for existing focusable elements that might exist within a scroller like a <textarea>.
- Media Capture Voice Isolation
MediaCaptureVoiceIsolation
chromestatus.comThis is about adding support in Chrome for the VoiceIsolation getUserMedia constraint (https://w3c.github.io/mediacapture-extensions/#voiceisolation-constraint). The constraint only takes effect on platforms where there is low-level support for voice-isolation style denoising. Currently this is limited to a selected number of ChromeOS devices, but further platforms will be added.
- Stylable Select
StylableSelect
Allows <button> and <datalist> in <selectlist> which replace the default button and listbox respectively, as well as introducing a new <selectedoption> element that shows the chosen value.
- Web Auth Allow Create In Cross Origin Frame
WebAuthAllowCreateInCrossOriginFrame
chromestatus.comThis feature allows web developers to create WebAuthn[0] credentials (that is, "publickey" credentials, aka passkeys) in cross-origin iframes. Two conditions are required for this new ability: 1. The iframe has a publickey-credentials-create-feature permission policy. 2. The iframe has transient user activation. This will allow developers to create passkeys in embedded scenarios, such as after an identity step-up flow where the Relying Party is providing a federated identity experience. [0]: https://w3c.github.io/webauthn/
- New features in Chromium 122 with missing descriptionApp Title
AppTitle
CSS Cross FadeCSSCrossFade
CSS Text Spacing TrimCSSTextSpacingTrim
Offset Mapping Unit VariableOffsetMappingUnitVariable
Performance Mark Feature UsagePerformanceMarkFeatureUsage
Top Level TpcdTopLevelTpcd
Web Authentication HintsWebAuthenticationHints
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