Limited support Useful when Anchor position container queries adds a clear capability without requiring fragile workarounds.

Browser support

Feature Desktop Mobile
Chrome
Edge
Firefox
Safari
Chrome Android
Safari iOS
anchor position queries
Experimental
143
143
143
anchor position queries fallback
Experimental

`fallback` feature

143
143
143
anchor position queries fallback any value
Experimental

`any` query value

143
143
143
CSS property
anchored
Experimental
143
143
143
1+Supported (version) Not supported Has note Sub-feature descriptions sourced from MDN Web Docs (CC BY-SA 2.5)

Syntax

CSS
.tooltip {
  position: absolute;
  position-anchor: --trigger;
}
@container anchored(fallback: bottom) {
  .tooltip::before { transform: rotate(180deg); }
}

Live demo

tooltiptop

CSS tooltiptop demo.

PreviewFullscreen

tooltipbottom

CSS tooltipbottom demo.

PreviewFullscreen

rightsidepopover

CSS rightsidepopover demo.

PreviewFullscreen

Use cases

  • Browser-native behavior

    Use Anchor position container queries to rely on the platform for behavior that would otherwise require extra code or CSS complexity.

  • Progressive enhancement

    Enhance the experience where support exists while keeping a solid baseline elsewhere.

Cautions

  • Check browser support and actual product need before adding a new platform feature widely.
  • Keep feature usage understandable so future contributors know why it was chosen.

Accessibility

  • New platform features should still preserve readable defaults and robust interaction patterns.
  • Verify that enhancement paths do not leave unsupported environments with a broken experience.