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 element() function

    This function renders a live image generated from an arbitrary HTML element

  3. 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.

  4. ::first-letter CSS pseudo-element selector

    CSS pseudo-element that allows styling only the first "letter" of text within an element. Useful for implementing initial caps or drop caps styling.

  5. Blending of HTML/SVG elements

    Allows blending between arbitrary SVG and HTML elements

  6. 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.

  7. Custom Elements (V1)

    One of the key features of the Web Components system, custom elements allow new HTML tags to be defined.

  8. Datalist element

    Method of setting a list of options for a user to select in a text field, while leaving the ability to enter a custom value.

  9. Details & Summary elements

    The <details> element generates a simple no-JavaScript widget to show/hide element contents, optionally by clicking on its child <summary> element.

  10. Dialog element

    Method of easily creating custom dialog boxes to display to the user with modal or non-modal options. Also includes a `::backdrop` pseudo-element for behind the element.

  11. Element.closest()

    DOM method that returns the current element if it matches the given selector, or else the closest ancestor element that matches the given selector, or else null.

  12. 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).

  13. 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.

  14. disabled attribute of the fieldset element

    Allows disabling all of the form control descendants of a fieldset via a `disabled` attribute on the fieldset element itself.

  15. Element.getBoundingClientRect()

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

  16. 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`.

  17. 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.

  18. Element.insertAdjacentHTML()

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

  19. Media Capture from DOM Elements API

    API to capture Real-Time video and audio from a DOM element, such as a `<video>`, `<audio>`, or `<canvas>` element via the `captureStream` method, in the form of a `MediaStream`

  20. Context menu item (menuitem element)

    Method of defining a context menu item, now deprecated and [removed from the HTML specification](https://github.com/whatwg/html/issues/2730).

  21. meter element

    Method of indicating the current level of a gauge.

  22. 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

  23. progress element

    Method of indicating a progress state.

  24. 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.

  25. Selectlist - Customizable select element

    Proposal for a customizable `<select>` element, currently defined as `<selectlist>`, previously `<selectmenu>`.

  26. SVG in HTML img element

    Method of displaying SVG images in HTML using <img>.

  27. 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`

  28. wbr (word break opportunity) element

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

  29. element api

  30. element api: id

  31. element api: part

  32. element api: role

  33. element api: slot

  34. svg element: a

  35. svg element: defs

  36. svg element: desc

  37. svg element: font

  38. svg element: g

  39. svg element: line

  40. svg element: mask

  41. svg element: mpath

  42. svg element: path

  43. svg element: rect

  44. svg element: set

  45. svg element: stop

  46. svg element: svg

  47. svg element: text

  48. svg element: tref

  49. svg element: use

  50. svg element: view