September 2019 web platform update
Now widely available on the web platform
Widely available
-
Classes: Classes are an object-oriented syntax for JavaScript prototypes. Learn more.
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Fetch (initial support): The
fetch()
method makes asynchronous HTTP requests. Learn more.
Newly available on the web platform
Newly available
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Print events: An alternative to
@media print
queries, thebeforeprint
andafterprint
events allow you to change the page for printing and and restore the page after printing. Learn more. -
Sticky positioning: The
position: sticky
CSS declaration positions an element in the normal flow until it crosses a specified threshold, at which points it becomes fixed (stuck) at that position. Learn more.
Now available in Chrome
Limited availability
-
Form-associated custom elements: Custom elements may act like built-in form elements, via the the
attachInternals()
method ofHTMLElement
and theElementInternals
API. Learn more. -
Lazy-loading images and iframes: The
loading="lazy"
attribute for<img>
and<iframe>
elements blocks loading the external resource until the user scrolls to that element's part of the page. Learn more.
Now available in Chrome Android
Limited availability
-
Form-associated custom elements: Custom elements may act like built-in form elements, via the the
attachInternals()
method ofHTMLElement
and theElementInternals
API. Learn more. -
Lazy-loading images and iframes: The
loading="lazy"
attribute for<img>
and<iframe>
elements blocks loading the external resource until the user scrolls to that element's part of the page. Learn more.
Now available in Safari
Limited availability
-
color-scheme: The
color-scheme
CSS property sets which color schemes (light or dark) an element uses and may prevent automatic dark mode adjustments by the browser. Learn more. -
Promise.allSettled(): The
Promise.allSettled()
static method waits for an array of promises to settle (resolve or reject). Learn more. -
Visual viewport API: The
visualViewport
API provides a way to query and modify the user-visible viewport of a web page. Learn more.
Now available in Safari on iOS
Limited availability
-
color-scheme: The
color-scheme
CSS property sets which color schemes (light or dark) an element uses and may prevent automatic dark mode adjustments by the browser. Learn more. -
prefers-color-scheme: The
prefers-color-scheme
CSS media query detects the requested color scheme, light or dark. Learn more. -
Promise.allSettled(): The
Promise.allSettled()
static method waits for an array of promises to settle (resolve or reject). Learn more. -
Visual viewport API: The
visualViewport
API provides a way to query and modify the user-visible viewport of a web page. Learn more.