Specification

https://www.w3.org/TR/selectors-4/

Explainer

https://github.com/w3c/csswg-drafts/blob/main/selectors-4/Selectors_4_Explainer.md

Links

• The WG's request for this TAG review:

  • https://github.com/w3c/csswg-drafts/issues/12799#issuecomment-3628969842

• TAG review of the previous version of this specification, if any:

  • https://github.com/w3ctag/design-reviews/issues/219
  • https://github.com/w3ctag/design-reviews/issues/233
  • https://github.com/w3ctag/design-reviews/issues/709
  • https://github.com/w3ctag/design-reviews/issues/1010
  • https://github.com/w3ctag/design-reviews/issues/998

• A description of what has changed since our previous review:

  • see Explainer, What is new in Selectors 4

• Web Platform Tests: <!-- Or other tests if this is not a web platform feature. -->

  • https://wpt.fyi/results/css/selectors/

<img width="1157" height="217" alt="Image" src="https://github.com/user-attachments/assets/26e5009b-04f9-47f8-98f5-0ccaaa5c8be7" />

The specification

• Follows the Web Platform Design Principles.
• Includes Security and Privacy Considerations sections based on answers to the Security/Privacy Questionnaire.

Where and by whom is the work is being done?

• GitHub repo: https://github.com/w3c/csswg-drafts

• Primary contacts:

  • Elika Etemad @fantasai Editor
  • Tab Atkins @tabatkins Editor
  • Chris Lilley @svgeesus Staff Contact
  • Alan Stearns @astearns Co-Chair

• Primary standards group developing this feature: W3C CSS WG

Feedback so far

• Active horizontal reviews:
  • https://github.com/w3c/csswg-drafts/issues/13469
• Multi-stakeholder feedback:
  • Selectors 4 is implemented in Chrome, Firefox, and Safari; also in Ladybird and Servo
  • WPT results for those five
• Major unresolved issues with or opposition to this specification:
  • No opposition
  • Some minor issues being resolved

You should also know that...

This mature and widely implemented specification is now being readied for a CR Snapshot before proceeding to W3C Recommendation. Newer work is in Selectors 5, which is outside the scope of this review.

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