This feature allows developers to specify decoding attribute on HTMLImageElement and SVGImageElement which would have one of two states: “async”: This indicates that the developer prefers responsiveness and performance over atomic presentation of image and non-image content. “sync”: This indicates that the developer prefers atomic presentation of content over responsiveness. "auto": This indicates a default state where the user-agent can select the behavior.



Established standard

Status in Chromium


Enabled by default (tracking bug) in:

  • Chrome for desktop release 64
  • Chrome for Android release 64

Consensus & Standardization

After a feature ships in Chrome, the values listed here are not guaranteed to be up to date.

  • No signal
  • No signal
  • In development
  • Positive


Search tags

img async, image async,

Last updated on 2020-11-09