1. 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.

  2. focusin & focusout events

    The `focusin` and `focusout` events fire just before the element gains or loses focus, and they bubble. By contrast, the `focus` and `blur` events fire after the focus has shifted, and don't bubble.

  3. JSON parsing

    Method of converting JavaScript objects to JSON strings and JSON back to objects using JSON.stringify() and JSON.parse()

  4. View Transitions API (single-document)

    Provides a mechanism for easily creating animated transitions between different DOM states, while also updating the DOM contents in a single step. This API is specific to single-document transitions, support for same-origin cross-document transitions is [being planned](https://github.com/WICG/view-transitions/blob/main/cross-doc-explainer.md).

  5. DOM Parsing and Serialization

    Various DOM parsing and serializing functions, specifically `DOMParser`, `XMLSerializer`, `innerHTML`, `outerHTML` and `insertAdjacentHTML`.

  6. audiocontext api: `audiocontext()` constructor: `options.sinkid` parameter

  7. audiocontext api: `sinkchange` event

  8. audiocontext api: sinkid

  9. audioprocessingevent api

  10. audioprocessingevent api: `audioprocessingevent()` constructor

  11. audioprocessingevent api: inputbuffer

  12. audioprocessingevent api: outputbuffer

  13. audioprocessingevent api: playbacktime

  14. audiosinkinfo api

  15. audiosinkinfo api: type

  16. document api: browsingtopics

  17. element api: `focusin` event

  18. htmlmediaelement api: sinkid

  19. mlgraphbuilder api: sin

  20. processinginstruction api

  21. processinginstruction api: sheet

  22. processinginstruction api: target

  23. scheduling api: isinputpending

  24. svgmissingglyphelement api

  25. xpathresult api: singlenodevalue

  26. types: `asin()`

  27. types: `<easing-function>`

  28. types: `<easing-function>`: `cubic-bezier()` with ordinate ∉ [0,1]

  29. types: `<easing-function>`: `linear()`

  30. types: `<easing-function>`: `steps()` with `start`, `end` or no direction

  31. types: `<easing-function>`: `steps()` with `start`, `end` or no direction: `jump-` keywords for `steps()`

  32. types: <ratio>: accepts a single <number> as a value.

  33. types: `sin()`

  34. headers http header: if-modified-since

  35. headers http header: if-unmodified-since

  36. headers http header: range: cors-safelisted request header with single `bytes` range

  37. javascript built-in: math: sin

  38. javascript built-in: math: sinh

  39. javascript built-in: temporal api: temporal.instant interface: temporal.instant.since()

  40. javascript built-in: temporal api: temporal.plaindatetime interface: temporal.plaindatetime.since()

  41. javascript built-in: temporal api: temporal.plaindate interface: temporal.plaindate.since()

  42. javascript built-in: temporal api: temporal.plaintime interface: temporal.plaintime.since()

  43. javascript built-in: temporal api: temporal.plainyearmonth interface: temporal.plainyearmonth.since()

  44. javascript built-in: temporal api: temporal.zoneddatetime interface: temporal.zoneddatetime.since()

  45. svg element: missing-glyph

  46. svg element: missing-glyph: d

  47. svg element: missing-glyph: horiz-adv-x

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

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

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