What is CSS cross-browser compatibility in 2023?

Dohány Tamás
2 min readApr 6, 2023
“CSS compatibility — AI version”


A thought experiment from the perspective of many years.

Earlier times, “cross-browser compatibility” was a super rhyme for agencies developing application. In 2000s.

Since @supports (2019) static method been, and container queries (2022) placed, CSS logic started transforming irreversible.


  • The browser support of style definitions been querying by @supports rules easily: https://caniuse.com/css-supports-api
  • The app/lib UI logic might been built for the most supported props, it is a personal interest at the first of the app/lib need to work with a huge range of devices!
  • Browsers cruel race increasingly rises face-to-face to support CSS features wider and earlier as well.
    Nobody like unsupported style definitions.

As we see, creating an app for “everybody” in 2023 means making CSS for…

  • a large scale of viewport range availability
    container queries from XS mobiles to 4K TVs.
  • a large number of browsers
    backward compatibility also represented by having default styles updated by @supports rule extensions if available.
  • the complexity of the application logic even more and more robust
    supporting x browser y version z viewport size. It is also can be solved.


Although in the age of Singularity, this is not our biggest problem available to create an app for a new arrival company, even so how we manage and keeps up the thing called Internet what is the citadel of human knowledge, hopefully not consumed finally by AI robots.