1. Audio element

    Method of playing sound on webpages (without requiring a plug-in). Includes support for the following media properties: `currentSrc`, `currentTime`, `paused`, `playbackRate`, `buffered`, `duration`, `played`, `seekable`, `ended`, `autoplay`, `loop`, `controls`, `volume` & `muted`

  2. CSS Filter Effects

    Method of applying filter effects using the `filter` property to elements, matching filters available in SVG. Filter functions include blur, brightness, contrast, drop-shadow, grayscale, hue-rotate, invert, opacity, sepia and saturate.

  3. Custom Elements (deprecated V0 spec)

    Original V0 version of the custom elements specification. See [Custom Elements V1](#feat=custom-elementsv1) for support for the latest version.

  4. document.elementFromPoint()

    Given coordinates for a point relative to the viewport, returns the element that a click event would be dispatched at if the user were to click the point (in other words, the element that hit-testing would find).

  5. Scroll methods on elements (scroll, scrollTo, scrollBy)

    Methods to change the scroll position of an element. Similar to setting `scrollTop` & `scrollLeft` properties, but also allows options to be passed to define the scroll behavior.

  6. Element.getBoundingClientRect()

    Method to get the size and position of an element's bounding box, relative to the viewport.

  7. HTML5 semantic elements

    HTML5 offers some new elements, primarily for semantic purposes. The elements include: `section`, `article`, `aside`, `header`, `footer`, `nav`, `figure`, `figcaption`, `time`, `mark` & `main`.

  8. HTMLElement.innerText

    A property representing the text within a DOM element and its descendants. As a getter, it approximates the text the user would get if they highlighted the contents of the element with the cursor and then copied to the clipboard.

  9. Element.insertAdjacentElement() & Element.insertAdjacentText()

    Methods for inserting an element or text before or after a given element, or appending or prepending an element or text to a given element's list of children.

  10. Element.insertAdjacentHTML()

    Inserts a string of HTML into a specified position in the DOM relative to the given element.

  11. Picture element

    A responsive images method to control which image resource a user agent presents to a user, based on resolution, media query and/or support for a particular image format

  12. Portals

    Portals enable seamless navigation between sites or pages. A new page can be loaded as an inset using the `<portal>` element (similar to an iframe) which can then seamlessly transition to the new navigated state when "activated".

  13. Element.scrollIntoViewIfNeeded()

    If the element is fully within the visible area of the viewport, it does nothing. Otherwise, the element is scrolled into view. A proprietary variant of the standard `Element.scrollIntoView()` method.

  14. Video element

    Method of playing videos on webpages (without requiring a plug-in). Includes support for the following media properties: `currentSrc`, `currentTime`, `paused`, `playbackRate`, `buffered`, `duration`, `played`, `seekable`, `ended`, `autoplay`, `loop`, `controls`, `volume` & `muted`

  15. wbr (word break opportunity) element

    Represents an extra place where a line of text may optionally be broken.

  16. elementinternals api: ariakeyshortcuts

  17. elementinternals api: ariasort

  18. elementinternals api: reportvalidity

  19. element api: animate: implicit to/from keyframes are supported

  20. element api: `animationstart` event

  21. element api: ariakeyshortcuts

  22. element api: ariasort

  23. element api: `compositionstart` event

  24. element api: `gesturestart` event

  25. element api: insertadjacenthtml

  26. element api: insertadjacenttext

  27. element api: part

  28. element api: `touchstart` event

  29. element api: `transitionstart` event

  30. css property: clip-path: on html elements

  31. css property: clip-path: on svg elements

  32. css property: content: element replacement

  33. css property: filter: on svg elements

  34. css property: mix-blend-mode: on svg elements

  35. html element: article

  36. html element: input: `type="range"`: tick mark support

  37. html element: input: `type="range"`: vertically-oriented slider support

  38. html element: ol: start

  39. html element: portal

  40. html element: rt

  41. html element: rtc

  42. html element: script: type: importmap

  43. svg element: font: vert-adv-y

  44. svg element: font: vert-origin-x

  45. svg element: font: vert-origin-y

  46. svg element: missing-glyph: vert-adv-y

  47. svg element: missing-glyph: vert-origin-x

  48. svg element: missing-glyph: vert-origin-y

  49. svg element: path: d: `d` as css property supports `path()`

  50. svg element: textpath: startoffset