Web features explorer

📅 August 2026 release notes

Newly available

The following features are newly available:

  • Media element pseudo-classes: The :playing, :paused, :seeking, :buffering, :stalled, :muted, and :volume-locked CSS pseudo-classes match <audio> and <video> elements based on their state.
  • sibling-count() and sibling-index(): The sibling-count() and sibling-index() CSS functions return integers that are useful to style elements based on their positions among siblings or on the number of siblings, for example as part of a calc() expression.

Widely available

The following features are now widely available:

  • Declarative shadow DOM: The shadowrootmode attribute on <template> creates a shadow root without the use of JavaScript. It is a declarative alternative to the attachShadow() method.

New in Chrome

The following features are now available in Chrome:

  • Connection allowlists: The Connection-Allowlist HTTP response header limits which requests a page may initiate using fetch and other APIs.
  • Reference target: The referenceTarget property of a ShadowRoot object forwards attributes such as for and aria-labelledby to elements inside a shadow DOM. You can use this to, for example, link a <label> to its <input> even if the <input> is in the shadow DOM of a web component.
  • window-drag: The window-drag: move CSS declaration sets an element as a window drag handle, like a device's app title bar. You can use this to add click-and-drag areas to an installed progressive web app, often alongside window controls overlay.

New in Chrome Android

The following features are now available in Chrome Android:

  • Connection allowlists: The Connection-Allowlist HTTP response header limits which requests a page may initiate using fetch and other APIs.
  • Reference target: The referenceTarget property of a ShadowRoot object forwards attributes such as for and aria-labelledby to elements inside a shadow DOM. You can use this to, for example, link a <label> to its <input> even if the <input> is in the shadow DOM of a web component.
  • window-drag: The window-drag: move CSS declaration sets an element as a window drag handle, like a device's app title bar. You can use this to add click-and-drag areas to an installed progressive web app, often alongside window controls overlay.

New in Edge

The following features are now available in Edge:

  • Connection allowlists: The Connection-Allowlist HTTP response header limits which requests a page may initiate using fetch and other APIs.
  • Reference target: The referenceTarget property of a ShadowRoot object forwards attributes such as for and aria-labelledby to elements inside a shadow DOM. You can use this to, for example, link a <label> to its <input> even if the <input> is in the shadow DOM of a web component.
  • window-drag: The window-drag: move CSS declaration sets an element as a window drag handle, like a device's app title bar. You can use this to add click-and-drag areas to an installed progressive web app, often alongside window controls overlay.