proposals Documentation

Tracking ECMAScript Proposals

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Technical Documentation: tc39/proposals

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Overview (`README.md`)

[ECMAScript](https://github.com/tc39/ecma262) proposals

ECMAScript Internationalization API Specification proposals

Contributing to proposals

Active proposals

Proposals follow this process document.
This list contains only stage 2 proposals and higher that have not yet been withdrawn/rejected, or become finished.
Stage 2 indicates that the committee expects these features to be developed and eventually included in the standard.

Stage 3

Proposal Author Champion Test262 Feature Flag Meeting Notes
Legacy RegExp features in JavaScript Claude Pache Mark MillerClaude Pache legacy-regexp  -2026‑01 -2024‑06 -2023‑07 -2017‑05 -2017‑05 -2017‑03 -2016‑09
Source Phase Imports Luca Casonato Guy BedfordLuca Casonato source-phase-imports  -2026‑05 -2026‑01 -2024‑10 -2024‑07 -2024‑06 -2023‑07 -2023‑05 -2023‑05 -2023‑03
Dynamic Code Brand Checks Nicolo Ribaudo Krzysztof KotowiczMike SamuelNicolo Ribaudo No test262 tests  -2026‑05 -2026‑01 -2024‑06 -2024‑04 -2021‑01 -2019‑12 -2019‑07
Deferring Module Evaluation Yulia StartsevGuy Bedford Nicolò Ribaudo import-defer testing plan  -2026‑07 -2026‑03 -2025‑02 -2024‑12 -2024‑12 -2024‑10 -2024‑06 -2024‑04 -2023‑07 -2022‑11 -2021‑01
Non-extensible Applies to Private Mark MillerShu-yu GuoChip MorningstarErik Marks Mark MillerShu-yu GuoChip MorningstarErik Marks nonextensible-applies-to-private  -2025‑09 -2025‑07 -2025‑04
Import Text Eemeli Aro Eemeli Aro import-text  -2026‑03 -2025‑11
Error Stack Accessor Jordan Harband Jordan HarbandMark Miller tests PR  -2026‑05 -2026‑03 -2025‑11 -2025‑02
RegExp Buffer Boundaries (\A, \z, \Z) Ron Buckton Ron Buckton tests PR  -2026‑05 -2026‑03 -2026‑01 -2023‑07 -2021‑12 -2021‑10
Await Dictionary Alexander J. Vincent Ashley ClaymoreJordan HarbandChris de Almeida await-dictionary tests 1 2  -2026‑07 -2025‑11 -2025‑09 -2023‑03
Curtailing the power of "Thenables" Matthew Gaudet Matthew Gaudet :question:  -2026‑09 -2026‑09 -2026‑07 -2026‑07 -2026‑05 -2026‑03 -2025‑07 -2025‑02

Stage 2.7

Proposal Author Champion Test262 Feature Flag Meeting Notes
Decorators Daniel EhrenbergKristen Hewell Garrett Kristen Hewell Garrett decorators testing plan  -2026‑05 -2025‑11 -2025‑02 -2024‑06 -2023‑11 -2023‑05 -2023‑03 -2023‑01 -2023‑01 -2022‑06 -2022‑03 -2022‑03 -2022‑03 -2021‑12 -2021‑07 -2020‑09 -2020‑07 -2020‑06 -2020‑03 -2019‑03 -2019‑01 -2018‑11 -2018‑09 -2018‑07 -2018‑05 -2018‑03 -2018‑01 -2018‑01 -2017‑09 -2017‑09 -2017‑07 -2016‑09 -2016‑07 -2016‑05 -2016‑01 -2015‑09 -2015‑05 -2015‑03 -2015‑01 -2014‑04
Decorator Metadata Kristen Hewell Garrett Kristen Hewell Garrett decorator-metadata  -2026‑05 -2024‑06 -2023‑05 -2023‑05 -2023‑03
ShadowRealm Caridy PatiñoJean-Francois Paradis Dave HermanMark MillerCaridy PatiñoLeo BalterRick WaldronChengzhong Wu ShadowRealm  -2025‑02 -2025‑02 -2024‑12 -2024‑06 -2024‑02 -2023‑11 -2023‑09 -2022‑11 -2022‑09 -2022‑06 -2022‑03 -2021‑12 -2021‑08 -2021‑07 -2021‑05 -2021‑04 -2021‑01 -2020‑11 -2020‑06 -2020‑02 -2018‑07 -2018‑05 -2017‑03 -2017‑01 -2015‑05 -2014‑06 -2014‑01
ESM Phase Imports Luca CasonatoGuy Bedford Luca CasonatoGuy Bedford :question:  -2026‑05 -2026‑03 -2024‑12 -2024‑12 -2024‑10 -2024‑06 -2024‑04 -2024‑02
Immutable ArrayBuffers Mark MillerPeter HoddieRichard GibsonJack Works Mark MillerPeter HoddieRichard GibsonJack Works :question:  -2025‑07 -2025‑05 -2025‑04 -2025‑02 -2024‑12 -2024‑10
Import Bytes Steven Salat Steven Salat Import Bytes  -2025‑09
JSON.parse options Robin RicardRichard ButtonNicolò RibaudoAshley Claymore Nicolò RibaudoAshley ClaymorePeter Klecha :question:  -2026‑07 -2026‑03 -2023‑07 -2022‑07
export all from Guy Bedford Nicolò Ribaudo :question: &nbsp-2026‑09 -2026‑05
Deferred Re-exports Nicolò Ribaudo Nicolò Ribaudo :question:  -2026‑09 -2026‑05 -2026‑01 -2025‑11 -2025‑09 -2025‑04 -2024‑04

Stage 2

Proposal Author Champion Stage 2.7 reviewers Meeting Notes
function.sent metaproperty Allen Wirfs-Brock Daniel EhrenbergDomenic Denicola  -2026-01 -2026‑01 -2024‑06 -2022‑06 -2019‑07 -2018‑03 -2015‑11 -2015‑11
throw expressions Ron Buckton Ron Buckton Nicolò Ribaudo  -2024‑06 -2024‑02 -2023‑09 -2023‑09 -2023‑07 -2018‑01 -2017‑11 -2017‑09 -2017‑07
Function implementation hiding Domenic DenicolaMichael Ficarra Michael Ficarra Yehuda KatzWaldemar HorwatMike Samuel  -2026‑01 -2024‑06 -2023‑07 -2020‑06 -2019‑12 -2019‑07 -2018‑05
collection normalization Bradley Farias Michael FicarraAshley ClaymoreJordan Harband  -2026‑01 -2021‑03 -2019‑07 -2019‑01
Module Expressions SurmaDaniel EhrenbergNicolò Ribaudo SurmaNicolò Ribaudo Leo BalterGuy BedfordMathieu HofmanJordan Harband  -2022‑11
Pipeline Operator J. S. ChoiJames DiGioiaRon BucktonTab Atkins J. S. ChoiRon BucktonTab Atkins Ross KirslingChristian Ulbrich  -2026‑01 -2023‑07 -2022‑03 -2022‑01 -2021‑08 -2021‑03 -2018‑03 -2017‑11 -2017‑09
Destructure Private Fields Justin Ridgewell Kevin Gibbons Robin RicardWaldemar HorwatSarah Groff Hennigh-PalermoJordan HarbandSergey Rubanov  -2026‑01 -2023‑07 -2021‑12
String.dedent Misha KaletskyHemanth HMJustin Ridgewell Hemanth HMJustin Ridgewell Robin RicardJordan HarbandMark CohenSarah Groff Hennigh-Palermo  -2026‑01 -2022‑11 -2022‑09 -2022‑06 -2020‑09
Module Declarations Daniel EhrenbergNicolò Ribaudo Mark MillerNicolò Ribaudo Richard GibsonGuy Bedford  -2022‑11
Symbol Predicates Robin RicardJordan Harband Ashley ClaymoreJordan Harband Daniel MinorNicolò RibaudoMathieu Hofman  -2026‑01 -2023‑09 -2023‑05 -2023‑01 -2022‑07
Async Iterator helpers Gus Caplan Michael FicarraJonathan KeslinKevin Gibbons Richard GibsonYulia StartsevJason Orendorff  -2026‑07 -2026‑07 -2025‑11 -2024‑06 -2023‑09 -2023‑05
Iterator.range Jack Works Jack Works Waldemar HorwatJordan Harband  -2026‑01 -2024‑04 -2023‑03
Async Context Chengzhong Wu Andreu BotellaChengzhong WuJustin Ridgewell James M SnellMark S. Miller  -2026‑05 -2025‑09 -2025‑07 -2025‑05 -2025‑04 -2024‑12 -2024‑10 -2024‑04 -2023‑09 -2023‑05 -2023‑03 -2023‑02 -2020‑07 -2020‑06
"Discard" (void) Bindings Ron Buckton Ron Buckton Ashley ClaymoreOliver Medhurst  -2026‑01 -2024‑10 -2024‑10 -2024‑06 -2024‑04 -2024‑02
Propagate active ScriptOrModule with JobCallback Record Chengzhong Wu Chengzhong Wu Nicolò RibaudoChris de Almeida  -2026‑01 -2024‑07
Structs: Fixed Layout Objects and Some Synchronization Primitives Shu-yu Guo Shu-yu Guo Mark MillerWaldemar HorwatYulia StartsevNicolò Ribaudo  -2024‑10 -2024‑06 -2024‑04 -2024‑02 -2023‑03
Extractors Ron Buckton Ron Buckton Jordan HarbandJustin Ridgewell  -2024‑10 -2024‑04 -2024‑02
SeededPRNG Tab Atkins Tab Atkins Kevin GibbonsJesse AlamaMark Miller  -2025‑05 -2025‑05
Math.clamp Oliver Medhurst Oliver Medhurst Jordan Harband  -2025‑05 -2025‑02
Native Promise Predicate Mathieu Hofman Mathieu Hofman Jordan HarbandJames SnellJustin Ridgewell  -2025‑09
Error.captureStackTrace Matthew Gaudet Matthew GaudetDan Minor Jordan HarbandMichael Ficarra  -2025‑11 -2025‑07 -2025‑02
Object.keysLength Ruben BridgewaterJordan Harband Ruben BridgewaterJordan Harband Eemeli AroJames Snell  -2025‑07
Sync Imports Guy Bedford Guy Bedford Nicolò RibaudoJames Snell  -2026‑01 -2024‑12
Amount Ben Allen Ben Allen Waldemar HorwatJordan Harband  -2026‑07 -2026‑05 -2026‑03 -2025‑11 -2025‑09 -2025‑09
Error code property James Snell James Snell Jordan HarbandRichard Gibson  -2026‑07 -2026‑07 -2026‑03
Fused Multiply-Add Waldemar Horwat Waldemar Horwat Jordan HarbandMichael Ficarra  -2026‑07
Bigint from exponential Richard Gibson Richard Gibson Michael FicarraRuben Bridgewater  -2026‑09 -2026‑07 -2026‑07
Composites Ashley Claymore Ashley Claymore Jordan HarbandMichael FicarraRoss Kirsling  -2026‑09 -2026‑07 -2025‑11 -2025‑11 -2025‑04

The test262 feature flag links to a code search of tests using that feature flag, which may constitute complete or partial coverage.
The :question: means there is no feature flag for tests yet.

Contributing to proposals

See Contributing to ECMAScript and How We Work for the most up-to-date information on contributing to proposals to TC39 standards and how proposals advance.

Onboarding proposals

Proposals that are Stage 1 and above must be transferred to the TC39 GitHub organization for discoverability and archival purposes. To onboard a proposal:

  1. Transfer your repository to the @tc39-transfer organization
    • if you are a TC39 delegate, but not a member of that organization, please contact @LJHarb
  2. The Github Administrator, or one of the chairs, will transfer your repository to the TC39 organization the next chance they get.

Note that as part of the onboarding process your repository name may be normalized. Don't worry, repo redirects will continue to work as long as you never create a fork, or a new repository, with the same name - although Github Pages redirects will be broken (please update your links!).


Overview (`ecma402/README.md`)

[ECMAScript Internationalization API Specification](https://github.com/tc39/ecma402) proposals

ECMAScript proposals

Active proposals

Proposals follow this process document.
This list contains only stage 1 proposals and higher that have not yet been withdrawn/rejected, or become finished.

Stage 3

Proposal Author Champion Test262 Feature Flag Meeting Notes
Keep trailing zeros in Intl.NumberFormat and Intl.PluralRules Eemeli Aro Eemeli Aro Intl.NumberFormat-v3  -2026-05 -2026‑03 -2025‑11 -2025‑07 -2025‑05

Stage 2.7

Proposal Author Champion Test262 Feature Flag Meeting Notes

Stage 2

Proposal Author Champion Stage 2.7 reviewers Meeting Notes
eraDisplay option for Intl.DateTimeFormat Louis-Aime Shane Carr, Louis-Aime Eemeli AroDaniel Minor  -2022‑11 -2021‑01
More Currency Display Choices Eemeli Aro Eemeli Aro Jordan HarbandNicolò Ribaudo  -2024‑12

Stage 1

Proposal Author Champion Meeting Notes
Smart Unit Preferences in Intl.NumberFormat Younies Mahmoud Younies Mahmoud  -2024‑10 -2024‑06 -2020‑06
Intl LocaleMatcher Long Ho Shane Carr, Long Ho  -2021‑01
Intl.Segmenter v2 Frank Yung-Fong Tang Frank Yung-Fong Tang  -2022‑01 -2021‑12
Intl.MessageFormat Eemeli Aro Eemeli Aro  -2024‑06 -2024‑04 -2024‑02 -2024‑02 -2023‑09 -2022‑03
Intl.MessageResource Eemeli Aro Eemeli Aro  -2022‑11
Intl.ZonedDateTimeFormat Frank Yung-Fong Tang Frank Yung-Fong Tang  -2023‑05
explore associating a unit with a number Shane Carr Shane Carr  -2025‑11
[Stable Formatting] stable-formatting Eemeli Aro Eemeli Aro  -2023‑09 -2025‑02 -2026‑05
Default Behaviours for some Intl APIs Eemeli Aro Eemeli Aro  -2026‑05
Intl Sequence Units Shane Carr Shane Carr  -2026‑07 -2026‑05
Intl Energy Units Johan Røed Nicolò Ribaudo, Shane Carr  -2026‑03 -2025‑11
Intl.DateTimeFormat Alignment With Other Standards Eemeli Aro Eemeli Aro  -2026‑07

Contributing new proposals

Please see Contributing to ECMAScript for the most up-to-date information on contributing proposals to this standard.

Onboarding existing proposals

Proposals that are Stage 1 and above must be transferred to the TC39 GitHub organization for discoverability and archival purposes. To onboard a proposal that lives outside the TC39 organization:

  1. Transfer your repository to the @tc39-transfer organization
  • if you are a TC39 delegate, but not an admin in that organization, please contact @LJHarb
  1. @bterlson, @gesa, or @codehag will transfer your repository to the TC39 organization the next chance they get.

Note that as part of the onboarding process your repository name may be normalized. Don't worry, repo redirects will continue to work as long as you never create a fork, or a new repository, with the same name - although Github Pages redirects will be broken (please update your links!).


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