1. AVIF image format

    A modern image format based on the [AV1 video format](/av1). AVIF generally has better compression than [WebP](/webp), JPEG, PNG and GIF and is designed to supersede them. AVIF competes with [JPEG XL](/jpegxl) which has similar compression quality and is generally seen as more feature-rich than AVIF.

  2. DOMMatrix

    The `DOMMatrix` interface represents 4x4 matrices, suitable for 2D and 3D operations. Supersedes the `WebKitCSSMatrix` and `SVGMatrix` interfaces.

  3. HEIF/HEIC image format

    A modern image format based on the [HEVC video format](/hevc). HEIC generally has better compression than [WebP](/webp), JPEG, PNG and GIF. It is hard for browsers to support HEIC because it is [complex and expensive to license](https://en.wikipedia.org/wiki/High_Efficiency_Video_Coding#Patent_licensing). [AVIF](/avif) and [JPEG XL](/jpegxl) provide free licenses and are designed to supersede HEIC.

  4. HTML Imports

    Deprecated method of including and reusing HTML documents in other HTML documents. Superseded by ES modules.

  5. JPEG 2000 image format

    JPEG 2000 was built to supersede the original JPEG format by having better compression and more features. [WebP](/webp), [AVIF](/avif) and [JPEG XL](/jpegxl) are all designed to supersede JPEG 2000.

  6. JPEG XL image format

    A modern image format optimized for web environments. JPEG XL generally has better compression than [WebP](/webp), JPEG, PNG and GIF and is designed to supersede them. JPEG XL competes with [AVIF](/avif) which has similar compression quality but fewer features overall.

  7. JPEG XR image format

    JPEG XR was built to supersede the original JPEG format by having better compression and more features. [WebP](/webp), [AVIF](/avif) and [JPEG XL](/jpegxl) are all designed to supersede JPEG XR.

  8. SPDY protocol

    Networking protocol for low-latency transport of content over the web. Superseded by HTTP version 2.

  9. Temporal

    A modern API for working with date and time, meant to supersede the original `Date` API.

  10. WebGPU

    An API for complex rendering and compute, using hardware acceleration. Use cases include demanding 3D games and acceleration of scientific calculations. Meant to supersede WebGL.

  11. WebP image format

    Image format (based on the VP8 video format) that supports lossy and lossless compression, as well as animation and alpha transparency. WebP generally has better compression than JPEG, PNG and GIF and is designed to supersede them. [AVIF](/avif) and [JPEG XL](/jpegxl) are designed to supersede WebP.

  12. css property: baseline-shift: super

  13. css property: font-variant-position: super

  14. css property: font-variant: super

  15. css property: vertical-align: super

  16. javascript built-in: json: javascript is a superset of json

  17. javascript built-in: set: issupersetof

  18. javascript operator: super

  19. flif / fuif / pik image formats