2026
1 featuresThe source property of a ToggleEvent object is the element which triggered the toggle event to fire for a popover, <dialog>, or <details> element, if applicable.
2025
1 features2024
1 featuresThe shadowrootmode attribute on <template> creates a shadow root without the use of JavaScript. It is a declarative alternative to the attachShadow() method.
2023
1 features2018
1 features2017
1 featuresThe srcset and sizes attributes for <img> elements set a list of possible sources for the image and a corresponding list of size conditions for choosing a source, to show a responsive image that fits the size of the display.
2015
3 featuresThe <dl>, <dt>, and <dd> HTML elements represent a list of terms and their associated descriptions. Use a description list to create glossaries or similar list of key-value pairs.
The style global HTML attribute applies inline CSS styling declarations to individual elements.
Limited Availability
7 featuresThe name="theme-color" attribute for the <meta> HTML element suggests a color that the browser can use to customize the display of the page or the browser user interface.
The headingoffset HTML attribute offsets the heading level of descendant <h1>–<h6> elements. The headingreset HTML attribute prevents heading offset computation from traversing beyond the element.
Interest invokers, registered by the interestfor HTML attribute, trigger events and actions on a target element when a user shows interest in the element, through behaviors such as hover, focus, or long-press. Pseudo-elements apply styles to sources and targets of interest.
The blocking="render" attribute for <link>, <script>, and <style> elements blocks rendering until the external script or stylesheet has been loaded. For <link rel="expect">, rendering is blocked until a specific element is in the DOM.
The focusgroup global HTML attribute combines descendant elements into a single tab stop, with arrow-key navigation between them, for toolbars, tabs, menus, radio groups, and other composite controls. It's an alternative to the sequential navigation of tabindex.
The popover="hint" global HTML attribute creates a popover that is subordinate to popovers with a popover="auto" attribute. You can use this to create tooltips that don't dismiss auto popovers.