Inactive Proposals
March 10, 2026 · View on GitHub
Inactive proposals are proposals that at one point were presented to the committee but were subsequently abandoned, withdrawn, or rejected.
| Proposal | Champion | Rationale | Meeting Notes |
|---|---|---|---|
| Callable class constructors | Yehuda Katz Allen Wirfs-Brock | Withdrawn: can be solved with decorators | -2016‑01 |
{Set,Map}.prototype.toJSON | David Bruant Jordan Harband | Rejected: better solved by a custom replacer function. | -2016‑03 |
| Typed Objects | Till Schneidereit (previously Dmitry Lomov, Niko Matsakis) | Postponed: waiting for WebAssembly requirements to become clearer | -2018‑11 -2014‑01 |
| Object enumerables | Leo Balter John-David Dalton | Rejected | -2016‑07 |
| Cancelable Promises | Domenic Denicola | Withdrawn | -2016‑09 -2016‑07 -2016‑05 |
| Proposed Grammar change to ES Modules | Bradley Farias | Rejected: No consensus on this specific solution. | -2017‑01 |
| Dynamic Module Reform | Caridy Patiño | Withdrawn: we decided to preserve the current semantics | -2018‑07 -2016‑09 |
| SIMD.JS - SIMD APIs | Peter Jensen Yehuda Katz | Stage 1: Start with SIMD in WASM; implementations not pursuing SIMD.js for now. | -2017‑03 -2016‑01 -2015‑09 -2015‑07 -2015‑05 -2014‑07 |
| Updates to Tail Calls to include an explicit syntactic opt-in | Brian Terlson Eric Faust | Inactive | -2016‑05 -2016‑03 -2016‑03 |
| Object.shallowEqual | Sebastian Markbage | Withdrawn | -2016‑07 |
%constructor%.construct | James M Snell | Never presented | Never presented |
Builtins.typeOf() and Builtins.is() | James M Snell | Withdrawn: can be solved in other ways | -2017‑09 |
| Tagged Collection Literals | Kat Marchán | Withdrawn: pursuing when new syntax and other alternatives | -2018‑05 |
Date.parse fallback semantics | Morgan Phillips | Inactive; likely replaced by uniform parsing of quasi-standard Date.parse input | -2016‑07 |
| Distinguishing literal strings | Mike West Adam Klein | Withdrawn: Trusted Types no longer a dependent | -2017‑11 |
| Annex B — HTML Attribute Event Handlers | Allen Wirfs-Brock | Withdrawn per PR comment | - 2019 07 |
| Normative ICU Reference | Domenic Denicola | Withdrawn; champion is no longer participating in TC39 | -2017‑05 |
| Zones | Domenic Denicola Miško Hevery | Withdrawn; champion is no longer participating in TC39 | -2016‑03 -2016‑01 |
| Blöcks | Domenic Denicola | Withdrawn; champion is no longer participating in TC39 | -2018‑05 |
| RegExp Atomic Groups & Possessive Quantifiers | Justin Ridgewell | Never presented; engines are not interested in the feature, mainly because it doesn't solve backtracking for most users | -2021‑10 |
| RefCollection | Robin Ricard | Withdrawn; replaced with Symbols as WeakMap keys; also there were OCAP/membrane concerns around providing a globally available pre-instantiated RefCollection | -2020‑04 |
| Generic Comparison | Hemanth HM Jordan Harband | Withdrawn: replaced with Array Equality | -2020‑06 |
from ... import | Bradley Farias | Never presented; preliminary feedback about syntax cost not being worth the weight | Never presented |
| TypedArray stride parameter | Shu-yu Guo | Withdrawn: concern about performance implications, and the proposal is not expressive enough | -2020‑09 -2020‑03 |
| Unused Function Parameters | Gus Caplan | Rejected: the need to solve the problem does not outweigh the hazards | -2020‑09 |
| Improving iteration on Objects | Jonathan Keslin | Withdrawn: concern about need for such an API | -2020‑02 |
String.prototype.at | Mathias Bynens Rick Waldron | Obsoleted by renamed String.prototype.item proposal | Never presented |
ArrayBuffer.prototype.transfer | Domenic Denicola Shu-yu Guo | Withdrawn: superseded by Resizable Buffers | -2018‑07 -2014‑09 |
deprecated | James M Snell | Never presented | Never presented |
| Function helpers | J. S. Choi | Presented and rejected before Stage 1 on 2021-10; split up into multiple subsequent proposals | -2021‑10 |
"use module" | Dave Herman | Inactive; champion does not wish to pursue | -2017‑07 |
| Function.pipe and flow | J.S. Choi | Withdrawn: rejected for stage 1 | -2022‑07 |
Symbol.thenable | Gus Caplan Jordan Harband Myles Borins | Withdrawn; changing thenability on Module Namespace objects is not web compatible, and allowing non-Promise use of "then" is not worth slowing down all Promise operations | -2018‑05 |
WeakRefs cleanupSome | Yulia Startsev Daniel Ehrenberg | Withdrawn; subsumed by WebAssembly JS Promise Integration, which avoids the long task issue | -2020‑07 |
| Operator overloading | Daniel Ehrenberg | Withdrawn | -2023‑11 -2019‑12 -2018‑01 |
| Extensible numeric literals | Daniel Ehrenberg | Withdrawn | -2020‑09 |
| JSON.tryParse | Jack Works | Rejected; some deemed this too specific a solution for a generalized language-wide problem | -2023‑11 |
| UUID | Benjamin Coe | Withdrawn; moved to crypto.randomUUID() in February 2023 | -2019‑12 -2019‑10 |
Math Extensions | Rick Waldron | Withdrawn: no interested champions in February 2024 | -2016‑07 |
| Generator arrow functions | Sergey Rubanov Brendan Eich | Withdrawn: no interested champions in February 2024 | -2016‑09 |
Math.signbit: IEEE-754 sign bit | JF Bastien | Withdrawn: no interested champions in February 2024 | -2017‑05 |
| Getting last element of Array | Keith Cirkel | Withdrawn; the Array#at proposal supersedes this work. | -2018‑03 |
| Sequence properties in Unicode property escapes | Mathias Bynens | Withdrawn; subsumed by RegExp v flag with set notation + properties of strings proposal | -2019‑10 -2018‑05 |
| Record & Tuple | Robin Ricard Richard Button | Withdrawn; subsumed by Composites | -2025‑04 -2025‑02 -2022‑11 -2022‑09 -2022‑07 -2021‑12 -2021‑10 -2021‑03 -2020‑09 -2020‑07 -2020‑06 -2020‑03 -2019‑10 |
| Dynamic Import Host Adjustment | Mike Samuel, Krzysztof Kotowicz | Withdrawn; no longer being pursued. | -2026‑03 -2019‑12 |
See also the active proposals, stage 1 proposals, stage 0 proposals, and finished proposals documents.