Specification

• https://github.com/whatwg/dom/pull/1404
• https://github.com/whatwg/html/pull/11741

Explainer

https://github.com/MicrosoftEdge/MSEdgeExplainers/blob/main/OpaqueRange/explainer.md

Links

• Previous early design review, if any: https://github.com/w3ctag/design-reviews/issues/1142
• An introduction to the feature, aimed at unfamiliar audiences: Introduction
• A description of the problems that end-users were facing before this proposal: User-Facing Problem
• Alternatives considered: Alternatives Considered
• Examples of how to use the proposal to solve the end-users' problems: Proposed Approach
• What do the end-users experience with this proposal: Proposed Approach
• User research you did to validate the problem and/or design, if any: No formal user research; relevant validation feedback is included under “Other feedback and reviews” below.
• Web Platform Tests: https://wpt.fyi/results/dom/ranges/tentative?label=experimental&label=master&aligned

The specification

• Follows the Web Platform Design Principles.
• Includes Security and Privacy Considerations sections based on answers to the Security/Privacy Questionnaire.
  • Filled out questionnaire: https://github.com/MicrosoftEdge/MSEdgeExplainers/blob/main/OpaqueRange/security-privacy-questionnaire.md

Where and by whom is the work is being done?

• GitHub repo:
  • https://github.com/whatwg/dom
  • https://github.com/whatwg/html
• Primary contacts:
  • Stephanie Zhang (@stephanieyzhang), Microsoft, Chromium implementer and spec contributor
  • Dan Clark (@dandclark), Microsoft, engineering lead and spec editor
  • Leo Lee (@leotlee), Microsoft, team lead
• Organization/project driving the specification: WHATWG
• This work is being funded by: Microsoft
• Primary standards group developing this feature: WHATWG
• Group intended to standardize this work: WHATWG
• Incubation and standards groups that have discussed the design:
  • WHATWG: https://github.com/whatwg/html/issues/11478
  • CSSWG: https://github.com/w3c/csswg-drafts/issues/10346
  • TPAC 2025 Meeting Minutes: https://www.w3.org/2025/11/11-whatwg-minutes.html

Feedback so far

• Multi-stakeholder feedback:
  • Chromium comments: Positive; Chromium is prototyping the feature and plans to begin developer and origin testing soon
  • Mozilla comments: https://github.com/mozilla/standards-positions/issues/1289 and https://github.com/whatwg/html/issues/11478#issuecomment-3887267749
  • WebKit comments: https://github.com/WebKit/standards-positions/issues/541
  • Other feedback and reviews:
    • https://github.com/w3c/csswg-drafts/issues/10346
    • https://github.com/w3c/csswg-drafts/issues/4603
    • https://github.com/MicrosoftEdge/MSEdgeExplainers/issues/1104
• Major unresolved issues with or opposition to this specification:
  • No major unresolved design objections at this time. The proposal has continued to evolve based on prior TAG feedback and ongoing multi-stakeholder discussion
• Status/issue trackers for implementations:
  • Chrome Status
  • Mozilla Bugzilla
  • WebKit's Bugzilla

You should also know that...

This proposal previously received early TAG design review in https://github.com/w3ctag/design-reviews/issues/1142, under its earlier name, FormControlRange, which was later renamed to OpaqueRange.

Since that review, the proposal has advanced to Stage 2, evolved into draft specification text in WHATWG DOM and WHATWG HTML, and incorporated feedback from Mozilla and Apple.

We are now requesting TAG specification review for OpaqueRange ahead of experimentation in Chromium.

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