Coverage
Auto-generated Baseline coverage report.
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Coverage report generated by scripts/generate-coverage.mjs
. Do NOT edit this file directly.
Baseline Coverage
- web-features:
v2.47.0
JavaScript Language (syntax)
- total:
33
- mapped:
33
- coverage:
100.0%
Feature ID | Name | Baseline | Year | Mapped | Mechanism | Delegates |
---|---|---|---|---|---|---|
arguments-callee | arguments.callee | limited | - | ✅ | delegate | core:no-caller |
async-await | Async functions | widely | 2017 | ✅ | delegate | es-x:no-async-functions |
async-generators | Async generators | widely | 2020 | ✅ | delegate | es-x:no-async-iteration |
atomics-wait-async | Atomics.waitAsync | limited | - | ✅ | delegate | es-x:no-atomics-waitasync |
bigint | BigInt | widely | 2020 | ✅ | delegate | es-x:no-bigint |
bigint64array | BigInt64Array | widely | 2021 | ✅ | self | self:no-bigint64array |
class-syntax | Classes | widely | 2016 | ✅ | delegate | es-x:no-classes |
date-get-year-set-year | getYear() and setYear() | limited | - | ✅ | delegate | es-x:no-date-prototype-getyear-setyear |
destructuring | Destructuring | widely | 2020 | ✅ | delegate | es-x:no-destructuring |
escape-unescape | escape() and unescape() | limited | - | ✅ | delegate | es-x:no-escape-unescape |
exponentiation | Exponentiation operator | widely | 2017 | ✅ | delegate | es-x:no-exponential-operators |
functions | Functions | widely | 2015 | ✅ | delegate | - |
functions-caller-arguments | Function caller and arguments | limited | - | ✅ | self | self:no-function-caller-arguments |
generators | Generators | widely | 2016 | ✅ | delegate | es-x:no-generators |
globalthis | globalThis | widely | 2020 | ✅ | delegate | es-x:no-global-this |
hashbang-comments | Hashbang comments | widely | 2020 | ✅ | delegate | es-x:no-hashbang |
html-wrapper-methods | HTML wrapper methods | limited | - | ✅ | delegate | es-x:no-string-create-html-methods |
javascript | JavaScript (initial core language support) | widely | 2015 | ✅ | delegate | - |
let-const | Let and const | widely | 2016 | ✅ | delegate | es-x:no-block-scoped-variables |
logical-assignments | Logical assignments | widely | 2020 | ✅ | delegate | es-x:no-logical-assignment-operators |
math-sum-precise | Math.sumPrecise() | limited | - | ✅ | self | self:no-math-sum-precise |
nullish-coalescing | Nullish coalescing | widely | 2020 | ✅ | delegate | es-x:no-nullish-coalescing-operators |
numeric-seperators | Numeric separators | widely | 2020 | ✅ | delegate | es-x:no-numeric-separators |
optional-catch-binding | Optional catch binding | widely | 2020 | ✅ | delegate | es-x:no-optional-catch-binding |
proxy-reflect | Proxy and Reflect | widely | 2016 | ✅ | delegate | es-x:no-proxy , es-x:no-reflect |
shared-memory | SharedArrayBuffer and Atomics | widely | 2021 | ✅ | delegate | es-x:no-shared-array-buffer , es-x:no-atomics |
spread | Spread syntax | widely | 2020 | ✅ | delegate | es-x:no-spread-elements , es-x:no-rest-spread-properties |
template-literals | Template literals | widely | 2020 | ✅ | delegate | es-x:no-template-literals |
temporal | Temporal | limited | - | ✅ | self | self:no-temporal |
top-level-await | Top-level await | widely | 2021 | ✅ | delegate | es-x:no-top-level-await |
unicode-point-escapes | Unicode point escapes | widely | 2015 | ✅ | delegate | es-x:no-unicode-codepoint-escapes |
weak-references | Weak references | widely | 2021 | ✅ | delegate | es-x:no-weakrefs |
with | with | limited | - | ✅ | delegate | core:no-with |
Web APIs (api.*)
- total:
486
- excluded (out-of-scope):
9
- included (in-scope):
477
- mapped:
465
- coverage:
97.5%
Feature ID | Name | Baseline | Year | Mapped | Patterns | Descriptors | Memo |
---|---|---|---|---|---|---|---|
a | <a> | widely | 2015 | ✅ | typed | 18 | - |
abortable-fetch | Abortable fetch | widely | 2019 | ✅ | typed | 2 | - |
aborting | AbortController and AbortSignal | widely | 2019 | ✅ | safe , typed | 9 | - |
abortsignal-any | AbortSignal.any() | newly | 2024 | ✅ | safe | 1 | - |
accelerometer | Accelerometer | limited | - | ✅ | safe , typed | 7 | - |
accesskey | accesskey | widely | 2015 | ✅ | typed | 2 | - |
active-view-transition | Active view transition | limited | - | ✅ | typed | 11 | - |
alerts | Alerts | widely | 2015 | ✅ | safe | 3 | - |
ambient-light | Ambient light sensor | limited | - | ✅ | safe , typed | 3 | - |
anchor-positioning | Anchor positioning | limited | - | ✅ | typed | 72 | - |
angle-instanced-arrays | ANGLE_instanced_arrays WebGL extension | widely | 2016 | ✅ | safe , typed | 5 | - |
animations-css | Animations (CSS) | widely | 2015 | ✅ | safe , typed | 13 | - |
app-file-handlers | File handlers | limited | - | ✅ | typed | 1 | - |
app-launch-handler | Launch handler | limited | - | ✅ | safe , typed | 3 | - |
aria-attribute-reflection | ARIA attribute reflection | newly | 2023 | ✅ | typed | 103 | - |
async-clipboard | Async clipboard | newly | 2024 | ✅ | safe , typed | 13 | - |
async-iterable-streams | Asynchronously iterable streams | limited | - | ✅ | typed | 2 | - |
attribution-reporting | Attribution reporting | limited | - | ✅ | typed | 6 | - |
audio | <audio> | widely | 2015 | ✅ | typed | 1 | - |
audio-session | Audio session | limited | - | ✅ | safe , typed | 2 | - |
audio-video-tracks | Audio and video tracks | limited | - | ✅ | typed | 23 | - |
audio-worklet | AudioWorklet | widely | 2021 | ✅ | safe , typed | 13 | - |
autocapitalize | autocapitalize | limited | - | ✅ | typed | 1 | - |
autocorrect | autocorrect | limited | - | ✅ | typed | 1 | - |
autofocus | autofocus | widely | 2015 | ✅ | typed | 3 | - |
autonomous-custom-elements | Autonomous custom elements | widely | 2020 | ✅ | safe , typed | 6 | - |
background-fetch | Background fetch | limited | - | ✅ | safe , typed | 26 | - |
background-sync | Background sync | limited | - | ✅ | safe , typed | 9 | - |
badging | Badging | limited | - | ✅ | safe | 2 | - |
barcode | Barcode detector | limited | - | ✅ | safe , typed | 3 | - |
barprop | BarProp | widely | 2015 | ✅ | safe , typed | 7 | - |
base | <base> | widely | 2015 | ✅ | typed | 2 | - |
base64encodedecode | Base64 encoding and decoding | widely | 2016 | ✅ | typed | 2 | - |
battery | Battery status | limited | - | ✅ | safe , typed | 10 | - |
beacons | Beacons | widely | 2018 | ✅ | safe | 1 | - |
beforeinstallprompt | beforeinstallprompt | limited | - | ✅ | safe , typed | 6 | - |
beforeunload | beforeunload | limited | - | ✅ | safe , typed | 2 | - |
bfcache-blocking-reasons | Back/forward cache blocking reasons | limited | - | ✅ | typed | 10 | - |
blocking-render | blocking-render | limited | - | ✅ | typed | 3 | - |
body | <body> | widely | 2015 | ❌ | - | - | - |
br | <br> | widely | 2015 | ❌ | - | - | - |
broadcast-channel | BroadcastChannel | widely | 2022 | ✅ | safe , typed | 6 | - |
button | <button> | widely | 2015 | ✅ | typed | 11 | - |
canvas | <canvas> | widely | 2015 | ✅ | typed | 5 | - |
canvas-2d | 2D canvas | widely | 2015 | ✅ | safe , typed | 101 | - |
canvas-2d-alpha | 2D canvas opacity | limited | - | ✅ | safe | 1 | - |
canvas-2d-color-management | Color management for 2D canvas | limited | - | ✅ | safe | 1 | - |
canvas-2d-desynchronized | Desynchronized 2D canvas | limited | - | ✅ | safe | 1 | - |
canvas-2d-willreadfrequently | willReadFrequently | newly | 2024 | ✅ | safe | 1 | - |
canvas-context-lost | contextlost and contextrestored | limited | - | ✅ | typed | 6 | - |
canvas-createconicgradient | Canvas createConicGradient() | newly | 2023 | ✅ | typed | 2 | - |
canvas-reset | Canvas reset() | newly | 2023 | ✅ | typed | 2 | - |
canvas-roundrect | Canvas roundRect() | newly | 2023 | ✅ | typed | 2 | - |
capture-stream-audio-video | captureStream() for <audio> and <video> | limited | - | ✅ | typed | 1 | - |
capture-stream-canvas | captureStream() for <canvas> | widely | 2020 | ✅ | typed | 3 | - |
cascade-layers | Cascade layers | widely | 2022 | ✅ | typed | 3 | - |
change-event | Change event | widely | 2015 | ✅ | typed | 1 | - |
channel-messaging | Channel messaging | widely | 2015 | ✅ | safe , typed | 9 | - |
check-visibility | checkVisibility() | newly | 2024 | ✅ | typed | 1 | - |
clip-path | clip-path | widely | 2021 | ✅ | typed | 2 | - |
clipboard-custom-format | Custom formats for clipboard items | limited | - | ✅ | typed | 1 | - |
clipboard-events | Clipboard events | widely | 2017 | ✅ | safe , typed | 5 | - |
clipboard-supports | ClipboardItem.supports() | newly | 2025 | ✅ | safe | 1 | - |
clipboard-svg | SVG clipboard items | limited | - | ✅ | typed | 1 | - |
clipboard-unsanitized-formats | Read unsanitized clipboard data | limited | - | ❌ | - | - | Permissioned/unsanitized data — not static-detectable |
closewatcher | CloseWatcher | limited | - | ✅ | safe , typed | 6 | - |
composed-ranges | Selection composed ranges | newly | 2025 | ✅ | typed | 1 | - |
composition-events | Composition events | widely | 2017 | ✅ | safe , typed | 5 | - |
compression-streams | Compression streams | newly | 2023 | ✅ | safe , typed | 6 | - |
compute-pressure | CPU compute pressure | limited | - | ✅ | safe , typed | 11 | - |
console | Console | widely | 2015 | ✅ | safe , typed | 21 | - |
constraint-validation | Constraint validation API | widely | 2018 | ✅ | typed | 55 | - |
constructed-stylesheets | Constructed stylesheets | newly | 2023 | ✅ | safe , typed | 5 | - |
contact-picker | Contact picker | limited | - | ✅ | safe , typed | 14 | - |
container-queries | Container queries | widely | 2023 | ✅ | typed | 2 | - |
content-index | Content Index | limited | - | ✅ | safe , typed | 7 | - |
content-visibility | content-visibility | limited | - | ✅ | safe , typed | 3 | - |
contenteditable | contenteditable | widely | 2015 | ✅ | typed | 2 | - |
contenteditable-plaintextonly | contenteditable-plaintextonly | newly | 2025 | ❌ | - | - | HTML attribute — use html-eslint |
controls-list | controlslist | limited | - | ✅ | typed | 1 | - |
cookie-enabled | cookieEnabled | newly | 2024 | ✅ | safe | 1 | - |
cookie-store | Cookie store | limited | - | ✅ | safe , typed | 18 | - |
cookies | Cookies | widely | 2015 | ✅ | typed | 1 | - |
counter-style | @counter-style | newly | 2023 | ✅ | typed | 11 | - |
createimagebitmap | createImageBitmap | newly | 2023 | ✅ | typed | 10 | - |
credential-management | Credential management | widely | 2020 | ✅ | safe , typed | 8 | - |
cross-document-view-transitions | Cross-document view transitions | limited | - | ✅ | typed | 2 | - |
csp | Content Security Policy (CSP) | widely | 2016 | ✅ | safe , typed | 19 | - |
css-escape | CSS.escape() | widely | 2020 | ✅ | safe | 1 | - |
css-object-model | CSS object model | widely | 2015 | ✅ | typed | 65 | - |
css-object-model-discouraged | CSS object model (DOM level 2) | limited | - | ✅ | typed | 19 | - |
css-supports | CSS.supports() | widely | 2020 | ✅ | safe | 1 | - |
css-typed-om | CSS typed object model | limited | - | ✅ | safe , typed | 104 | - |
customized-built-in-elements | Customized built-in elements | limited | - | ✅ | typed | 1 | - |
data | <data> | widely | 2017 | ✅ | typed | 1 | - |
datalist | <datalist> | limited | - | ✅ | typed | 1 | - |
dataset | Dataset | widely | 2015 | ✅ | typed | 3 | - |
declarative-shadow-dom | Declarative shadow DOM | newly | 2024 | ✅ | typed | 4 | - |
dedicated-workers | Dedicated workers | widely | 2015 | ✅ | safe , typed | 23 | - |
del | <del> | widely | 2015 | ✅ | typed | 2 | - |
description-list | Description list | widely | 2015 | ❌ | - | - | HTML semantics — use html-eslint |
details | <details> | widely | 2020 | ✅ | typed | 2 | - |
details-name | Mutually exclusive <details> elements | newly | 2024 | ✅ | typed | 1 | - |
device-memory | Device memory | limited | - | ✅ | safe , typed | 2 | - |
device-orientation-events | Device orientation events | newly | 2023 | ✅ | safe , typed | 21 | - |
device-posture | Device posture | limited | - | ✅ | safe , typed | 3 | - |
devicepixelratio | devicePixelRatio | limited | - | ✅ | safe | 1 | - |
dialog | <dialog> | widely | 2022 | ✅ | typed | 7 | - |
dialog-closedby | <dialog closedby> | limited | - | ✅ | typed | 1 | - |
digital-goods | Digital goods | limited | - | ✅ | safe | 1 | - |
dirname | dirname | newly | 2023 | ✅ | typed | 2 | - |
div | <div> | widely | 2015 | ❌ | - | - | - |
document-caretpositionfrompoint | document.caretPositionFromPoint() | limited | - | ✅ | typed | 4 | - |
document-colors | Document colors | limited | - | ✅ | typed | 5 | - |
document-picture-in-picture | Document picture-in-picture | limited | - | ✅ | safe , typed | 6 | - |
document-write | document.write() | limited | - | ✅ | typed | 4 | - |
dom | DOM | widely | 2015 | ✅ | safe , typed | 253 | - |
dom-geometry | DOM Geometry | widely | 2020 | ✅ | safe , typed | 132 | - |
domparser | DOMParser | widely | 2016 | ✅ | safe , typed | 2 | - |
download | download | widely | 2019 | ✅ | typed | 3 | - |
draganddrop | Drag and Drop | widely | 2015 | ✅ | safe , typed | 29 | - |
edit-context | EditContext | limited | - | ✅ | safe , typed | 34 | - |
element-capture | Element capture | limited | - | ✅ | safe , typed | 2 | - |
element-from-point | document.elementFromPoint() and document.elementsFromPoint() | widely | 2020 | ✅ | typed | 2 | - |
element-timing | Element timing | limited | - | ✅ | typed | 11 | - |
embed | <embed> | widely | 2020 | ✅ | typed | 5 | - |
encrypted-media-extensions | Encrypted media extensions | widely | 2019 | ✅ | safe , typed | 36 | - |
enterkeyhint | enterkeyhint | widely | 2021 | ✅ | typed | 1 | - |
event-timing | Event timing | limited | - | ✅ | typed | 15 | - |
events | Events | widely | 2015 | ✅ | safe , typed | 20 | - |
execcommand | execCommand() | limited | - | ✅ | typed | 6 | - |
ext-blend-minmax | EXT_blend_minmax WebGL extension | widely | 2018 | ✅ | safe | 2 | - |
ext-color-buffer-float | EXT_color_buffer_float WebGL extension | widely | 2021 | ✅ | safe | 2 | - |
ext-color-buffer-half-float | EXT_color_buffer_half_float WebGL extension | widely | 2020 | ✅ | safe | 2 | - |
ext-disjoint-timer-query | EXT_disjoint_timer_query WebGL extension | limited | - | ✅ | safe , typed | 10 | - |
ext-float-blend | EXT_float_blend WebGL extension | limited | - | ✅ | safe | 2 | - |
ext-frag-depth | EXT_frag_depth WebGL extension | limited | - | ✅ | safe | 2 | - |
ext-shader-texture-lod | EXT_shader_texture_lod WebGL extension | limited | - | ✅ | safe | 2 | - |
ext-srgb | EXT_sRGB WebGL extension | widely | 2020 | ✅ | safe | 2 | - |
ext-texture-compression-bptc | EXT_texture_compression_bptc WebGL extension | limited | - | ✅ | safe | 2 | - |
ext-texture-compression-rgtc | EXT_texture_compression_rgtc WebGL extension | limited | - | ✅ | safe | 2 | - |
ext-texture-filter-anisotropic | EXT_texture_filter_anisotropic WebGL extension | widely | 2016 | ✅ | safe | 2 | - |
ext-texture-norm16 | EXT_texture_norm16 WebGL extension | limited | - | ✅ | safe | 2 | - |
external | window.external | limited | - | ✅ | typed | 2 | - |
eyedropper | Eyedropper | limited | - | ✅ | safe , typed | 3 | - |
fast-seek | fastSeek() | limited | - | ✅ | typed | 1 | - |
fedcm | Federated credential management | limited | - | ✅ | typed | 1 | - |
federated-credentials | Federated credentials | limited | - | ✅ | safe , typed | 5 | - |
fencedframe | <fencedframe> | limited | - | ✅ | safe , typed | 11 | - |
fetch | Fetch | widely | 2017 | ✅ | safe , typed | 61 | - |
fetch-priority | Fetch priority | newly | 2024 | ✅ | typed | 4 | - |
fetch-request-streams | Fetch upload streams | limited | - | ✅ | typed | 1 | - |
fetchlater | fetchLater | limited | - | ✅ | safe , typed | 2 | - |
fieldset | <fieldset> and <legend> | widely | 2015 | ✅ | typed | 6 | - |
file | File API | widely | 2020 | ✅ | safe , typed | 35 | - |
file-system-access | File system access | limited | - | ✅ | safe , typed | 10 | - |
focus-events | Focus events | widely | 2015 | ✅ | safe , typed | 8 | - |
font-face | @font-face | widely | 2016 | ✅ | typed | 1 | - |
font-loading | Font loading | widely | 2020 | ✅ | safe , typed | 37 | - |
font-metric-overrides | Font metric overrides | limited | - | ✅ | typed | 3 | - |
font-palette | font-palette | widely | 2022 | ✅ | typed | 4 | - |
font-variant-alternates | font-variant-alternates | newly | 2023 | ✅ | typed | 18 | - |
form | <form> | widely | 2015 | ✅ | safe , typed | 24 | - |
form-associated-custom-elements | Form-associated custom elements | newly | 2023 | ✅ | typed | 10 | - |
fullscreen | Fullscreen API | limited | - | ✅ | typed | 10 | - |
gamepad | Gamepad | widely | 2017 | ✅ | safe , typed | 17 | - |
gamepad-haptics | Gamepad haptic feedback | limited | - | ✅ | typed | 7 | - |
gamepad-touch | Gamepad touch buttons | limited | - | ✅ | typed | 1 | - |
gamepad-vr | Gamepad VR hands and poses | limited | - | ✅ | typed | 11 | - |
geolocation | Geolocation | widely | 2015 | ✅ | safe , typed | 22 | - |
get-computed-style | getComputedStyle() | widely | 2015 | ✅ | safe | 1 | - |
getboxquads | getBoxQuads() | limited | - | ✅ | typed | 3 | - |
gethtml | getHTML() | newly | 2024 | ✅ | typed | 2 | - |
gpc | Global privacy control | limited | - | ✅ | safe , typed | 2 | - |
gyroscope | Gyroscope | limited | - | ✅ | safe , typed | 5 | - |
hardware-concurrency | hardwareConcurrency | widely | 2022 | ✅ | safe , typed | 2 | - |
hashchange | hashchange | widely | 2015 | ✅ | safe , typed | 4 | - |
head | <head> | widely | 2015 | ❌ | - | - | - |
headings | <h1> through <h6> | widely | 2015 | ❌ | - | - | - |
hidden-until-found | hidden-until-found | limited | - | ✅ | typed | 1 | - |
highlight | Custom highlights | limited | - | ✅ | safe , typed | 26 | - |
history | History | widely | 2015 | ✅ | safe , typed | 13 | - |
hr | <hr> | widely | 2015 | ❌ | - | - | - |
html | <html> | widely | 2015 | ❌ | - | - | - |
html-media-capture | HTML media capture | limited | - | ✅ | typed | 1 | - |
idle-detection | Idle detection | limited | - | ✅ | safe , typed | 6 | - |
iframe | <iframe> | widely | 2015 | ✅ | typed | 8 | - |
iframe-credentialless | Credentialless iframes | limited | - | ✅ | safe , typed | 2 | - |
iframe-sandbox | Sandboxed iframes | widely | 2015 | ✅ | typed | 1 | - |
iframe-srcdoc | srcdoc | widely | 2020 | ✅ | typed | 1 | - |
image-maps | Image maps | widely | 2015 | ✅ | typed | 22 | - |
imagebitmaprenderingcontext | ImageBitmapRenderingContext | widely | 2020 | ✅ | typed | 2 | - |
img | <img> | widely | 2015 | ✅ | typed | 13 | - |
import | @import | widely | 2015 | ✅ | typed | 3 | - |
indexeddb | IndexedDB | widely | 2021 | ✅ | safe , typed | 99 | - |
inert | inert | newly | 2023 | ✅ | typed | 1 | - |
ink | Ink | limited | - | ✅ | safe , typed | 4 | - |
input | <input> | widely | 2015 | ✅ | typed | 36 | - |
input-checkbox | input-checkbox | widely | 2015 | ✅ | typed | 2 | - |
input-color | input-color | limited | - | ✅ | typed | 2 | - |
input-date-time | Date and time <input> types | widely | 2021 | ✅ | typed | 1 | - |
input-event | input (event) | widely | 2020 | ✅ | safe , typed | 8 | - |
input-file | input-file | widely | 2015 | ✅ | typed | 1 | - |
input-image | input-image | widely | 2015 | ✅ | typed | 1 | - |
input-number | input-number | widely | 2015 | ✅ | typed | 6 | - |
inputmode | inputmode | widely | 2021 | ✅ | typed | 1 | - |
insertable-streams | Insertable streams for MediaStreamTrack | limited | - | ✅ | safe , typed | 6 | - |
intersection-observer | Intersection observer | widely | 2019 | ✅ | safe , typed | 20 | - |
invoker-commands | Invoker commands | limited | - | ✅ | safe , typed | 6 | - |
is-input-pending | isInputPending() | limited | - | ✅ | safe , typed | 2 | - |
is-secure-context | isSecureContext | widely | 2018 | ✅ | typed | 1 | - |
js-modules | JavaScript modules | widely | 2018 | ✅ | typed | 1 | - |
js-modules-service-workers | JavaScript modules in service workers | limited | - | ✅ | typed | 1 | - |
js-modules-shared-workers | JavaScript modules in shared workers | limited | - | ✅ | safe | 1 | - |
js-modules-workers | JavaScript modules in workers | newly | 2023 | ✅ | safe | 1 | - |
keyboard-events | Keyboard events | widely | 2015 | ✅ | safe , typed | 13 | - |
keyboard-lock | Keyboard lock | limited | - | ✅ | safe , typed | 3 | - |
keyboard-map | Keyboard map | limited | - | ✅ | typed | 9 | - |
khr-parallel-shader-compile | KHR_parallel_shader_compile WebGL extension | limited | - | ✅ | safe | 2 | - |
label | <label> | widely | 2015 | ✅ | typed | 3 | - |
lang-attr | lang | widely | 2015 | ✅ | typed | 1 | - |
language | Language | widely | 2015 | ✅ | safe , typed | 6 | - |
largest-contentful-paint | Largest contentful paint (LCP) | limited | - | ✅ | typed | 7 | - |
layout-instability | Layout instability | limited | - | ✅ | typed | 9 | - |
link | <link> | widely | 2015 | ✅ | typed | 11 | - |
link-rel-prefetch | link-rel-prefetch | limited | - | ❌ | - | - | HTML link rel — use html-eslint |
list-elements | <ol>, <ul>, and <li> | widely | 2015 | ✅ | typed | 4 | - |
loading-lazy | Lazy-loading images and iframes | newly | 2023 | ✅ | typed | 2 | - |
local-fonts | Local fonts | limited | - | ✅ | safe , typed | 7 | - |
local-network-access | Local network access | limited | - | ✅ | typed | 1 | - |
localstorage | localStorage and sessionStorage | widely | 2015 | ✅ | safe , typed | 15 | - |
location | Location | widely | 2015 | ✅ | safe , typed | 16 | - |
long-animation-frames | Long animation frames | limited | - | ✅ | typed | 17 | - |
longtasks | Long tasks | limited | - | ✅ | typed | 7 | - |
magnetometer | Magnetometer | limited | - | ✅ | safe , typed | 5 | - |
managed-media-source | Managed media source | limited | - | ✅ | safe , typed | 5 | - |
matchmedia | matchMedia | widely | 2015 | ✅ | safe , typed | 8 | - |
mathml | MathML | widely | 2023 | ✅ | typed | 6 | - |
measure-memory | Memory measurement | limited | - | ✅ | typed | 1 | - |
media-capabilities | Media capabilities | widely | 2022 | ✅ | safe , typed | 4 | - |
media-capture | Media capture | widely | 2017 | ✅ | safe , typed | 44 | - |
media-playback-quality | Media playback quality | widely | 2020 | ✅ | typed | 4 | - |
media-session | Media session | limited | - | ✅ | safe , typed | 17 | - |
media-source | Media source | limited | - | ✅ | safe , typed | 45 | - |
mediacontroller | MediaController | limited | - | ✅ | safe , typed | 16 | - |
mediastream-recording | MediaStream recording | widely | 2021 | ✅ | safe , typed | 22 | - |
menu | <menu> | widely | 2015 | ❌ | - | - | - |
messageerror | messageerror | newly | 2023 | ✅ | safe , typed | 6 | - |
meta | <meta> | widely | 2015 | ✅ | typed | 4 | - |
meter | <meter> | widely | 2018 | ✅ | typed | 7 | - |
mouse-events | Mouse events | widely | 2015 | ✅ | safe , typed | 33 | - |
move-before | moveBefore() | limited | - | ✅ | typed | 3 | - |
mutation-events | Mutation events | limited | - | ✅ | typed | 6 | - |
mutationobserver | MutationObserver | widely | 2015 | ✅ | safe , typed | 13 | - |
namespace | @namespace | widely | 2015 | ✅ | typed | 2 | - |
navigation | Navigation API | limited | - | ✅ | safe , typed | 52 | - |
navigation-timing | Navigation timing | widely | 2021 | ✅ | typed | 12 | - |
navigator | Navigator | widely | 2015 | ✅ | safe | 1 | - |
nesting | Nesting | newly | 2023 | ✅ | typed | 4 | - |
network-information | Network Information | limited | - | ✅ | safe , typed | 9 | - |
non-cookie-storage-access | Non-cookie storage access | limited | - | ✅ | typed | 12 | - |
notifications | Notifications | limited | - | ✅ | safe , typed | 34 | - |
numeric-factory-functions | Numeric factory functions | limited | - | ✅ | safe | 63 | - |
object | <object> | widely | 2015 | ✅ | typed | 9 | - |
observable | Observable | limited | - | ✅ | safe , typed | 28 | - |
oes-element-index-uint | OES_element_index_uint WebGL extension | widely | 2015 | ✅ | safe | 2 | - |
oes-fbo-render-mipmap | OES_fbo_render_mipmap WebGL extension | widely | 2021 | ✅ | safe | 2 | - |
oes-standard-derivatives | OES_standard_derivatives WebGL extension | widely | 2015 | ✅ | safe | 2 | - |
oes-texture-float | OES_texture_float WebGL extension | widely | 2015 | ✅ | safe | 2 | - |
oes-texture-float-linear | OES_texture_float_linear WebGL extension | widely | 2015 | ✅ | safe | 2 | - |
oes-texture-half-float | OES_texture_half_float WebGL extension | widely | 2016 | ✅ | safe | 2 | - |
oes-texture-half-float-linear | OES_texture_half_float_linear WebGL extension | limited | - | ✅ | safe | 2 | - |
oes-vertex-array-object | OES_vertex_array_object WebGL extension | widely | 2018 | ✅ | safe , typed | 6 | - |
offline-audio-context | OfflineAudioContext | widely | 2021 | ✅ | safe , typed | 8 | - |
offscreen-canvas | Offscreen canvas | newly | 2023 | ✅ | safe , typed | 73 | - |
online | Online status | widely | 2015 | ✅ | safe , typed | 6 | - |
orientation-sensor | Orientation Sensor | limited | - | ✅ | safe , typed | 14 | - |
origin-private-file-system | Origin private file system | newly | 2023 | ✅ | typed | 19 | - |
output | <output> | widely | - | ✅ | safe , typed | 8 | - |
ovr-multiview2 | OVR_multiview2 WebGL extension | limited | - | ✅ | safe , typed | 3 | - |
p | <p> | widely | 2015 | ❌ | - | - | - |
page-lifecycle | Page lifecycle | limited | - | ✅ | typed | 3 | - |
page-transition-events | Page transition events | widely | 2015 | ✅ | safe , typed | 4 | - |
page-visibility | Page visibility | widely | 2015 | ✅ | typed | 3 | - |
page-visibility-state | Page visibility state | limited | - | ✅ | typed | 4 | - |
paint | paint() | limited | - | ✅ | safe , typed | 45 | - |
paint-timing | Paint timing | limited | - | ✅ | typed | 2 | - |
parse-html-unsafe | Unsanitized HTML parsing methods | limited | - | ✅ | safe , typed | 3 | - |
partitioned-cookies | Partitioned cookies | limited | - | ❌ | - | - | Storage/partitioning semantics — not static-detectable |
password-credentials | Password credentials | limited | - | ✅ | safe , typed | 4 | - |
payment-handler | Payment handler | limited | - | ✅ | safe , typed | 23 | - |
payment-request | Payment request | limited | - | ✅ | safe , typed | 24 | - |
pdf-viewer | pdfViewerEnabled | newly | 2023 | ✅ | safe | 1 | - |
performance | Performance | widely | 2015 | ✅ | safe , typed | 29 | - |
performancetiming | PerformanceTiming and PerformanceNavigation | limited | - | ✅ | typed | 27 | - |
periodic-background-sync | Periodic background sync | limited | - | ✅ | safe , typed | 7 | - |
permissions | Permissions | widely | 2022 | ✅ | safe , typed | 7 | - |
picture | <picture> | widely | 2016 | ❌ | - | - | - |
picture-in-picture | Picture-in-picture (video) | limited | - | ✅ | safe , typed | 13 | - |
ping | ping | limited | - | ✅ | typed | 3 | - |
pointer-events-api | Pointer Events | widely | 2020 | ✅ | safe , typed | 31 | - |
pointer-lock | Pointer lock | limited | - | ✅ | typed | 5 | - |
popover | Popover | newly | 2025 | ✅ | safe , typed | 12 | - |
popover-hint | popover-hint | limited | - | ❌ | - | - | HTML attribute — use html-eslint |
postmessage | postMessage | widely | 2015 | ✅ | safe , typed | 11 | - |
pre | <pre> | widely | 2015 | ❌ | - | - | - |
preloading-responsive-images | Preloading responsive images | newly | 2023 | ✅ | typed | 2 | - |
presentation-api | Presentation API | limited | - | ✅ | safe , typed | 30 | - |
preserves-pitch | preservesPitch | newly | 2023 | ✅ | typed | 1 | - |
window.print() | newly | 2023 | ✅ | safe | 1 | - | |
print-events | Print events | widely | 2019 | ✅ | safe | 2 | - |
private-click-measurement | Private click measurement | limited | - | ✅ | typed | 1 | - |
profiler | Profiler | limited | - | ✅ | safe , typed | 4 | - |
progress | <progress> | widely | 2015 | ✅ | typed | 4 | - |
push | Push messages | newly | 2023 | ✅ | safe , typed | 26 | - |
q | <q> | widely | 2015 | ✅ | typed | 1 | - |
readable-byte-streams | Readable byte streams | limited | - | ✅ | safe , typed | 13 | - |
readablestream-from | ReadableStream.from() | limited | - | ✅ | safe | 1 | - |
referrer-policy | Referrer policy | widely | 2021 | ✅ | typed | 6 | - |
region-capture | Region capture | limited | - | ✅ | safe , typed | 3 | - |
registered-custom-properties | Registered custom properties | newly | 2024 | ✅ | safe , typed | 5 | - |
registerprotocolhandler | registerProtocolHandler | limited | - | ✅ | safe | 2 | - |
remote-playback | Remote playback | limited | - | ✅ | typed | 9 | - |
reporting | Reporting API | limited | - | ✅ | safe , typed | 18 | - |
request-animation-frame | requestAnimationFrame() | widely | 2015 | ✅ | safe | 2 | - |
request-animation-frame-workers | requestAnimationFrame() in workers | newly | 2023 | ✅ | typed | 2 | - |
request-video-frame-callback | requestVideoFrameCallback() | newly | 2024 | ✅ | typed | 2 | - |
requestclose | dialog.requestClose() | newly | 2025 | ✅ | typed | 1 | - |
requestidlecallback | requestIdleCallback() | limited | - | ✅ | safe , typed | 4 | - |
resize-observer | Resize observer | widely | 2020 | ✅ | safe , typed | 11 | - |
resource-size | Resource size | newly | 2023 | ✅ | typed | 3 | - |
resource-timing | Resource timing | widely | 2017 | ✅ | typed | 24 | - |
sanitizer | Sanitizer API | limited | - | ✅ | safe , typed | 13 | - |
savedata | Save-Data | limited | - | ✅ | typed | 1 | - |
scheduler | Scheduler API | limited | - | ✅ | safe , typed | 9 | - |
scope | @scope | limited | - | ✅ | typed | 2 | - |
scoped-custom-element-registries | Scoped custom element registries | limited | - | ✅ | safe , typed | 6 | - |
screen | Screen | widely | 2015 | ✅ | typed | 6 | - |
screen-capture | Screen capture | limited | - | ✅ | safe , typed | 3 | - |
screen-orientation | Screen orientation | newly | 2023 | ✅ | typed | 4 | - |
screen-orientation-lock | Screen orientation lock | limited | - | ✅ | typed | 2 | - |
screen-wake-lock | Screen wake lock | newly | 2025 | ✅ | safe , typed | 7 | - |
script | <script> and <noscript> | widely | 2015 | ✅ | safe , typed | 8 | - |
scroll-driven-animations | Scroll-driven animations | limited | - | ✅ | safe , typed | 7 | - |
scroll-elements | Scroll methods on elements | widely | 2020 | ✅ | safe , typed | 15 | - |
scroll-into-view | scrollIntoView() | widely | 2020 | ✅ | typed | 1 | - |
scroll-snap-events | Scroll snap events | limited | - | ✅ | safe , typed | 9 | - |
scroll-to-text-fragment | Scroll to text fragment | newly | 2024 | ✅ | typed | 1 | - |
scrollend | scrollend | limited | - | ✅ | typed | 2 | - |
select | <select> | widely | 2015 | ✅ | typed | 29 | - |
selection-api | Selection | widely | 2017 | ✅ | safe , typed | 73 | - |
serial | Web serial | limited | - | ✅ | safe , typed | 15 | - |
serializable-errors | Serializable errors | limited | - | ✅ | typed | 1 | - |
server-sent-events | Server-sent events | widely | 2020 | ✅ | safe , typed | 9 | - |
server-timing | Server timing | newly | 2023 | ✅ | typed | 5 | - |
service-workers | Service workers | widely | 2018 | ✅ | safe , typed | 84 | - |
setinterval | setInterval | widely | 2015 | ✅ | typed | 2 | - |
settimeout | setTimeout() | widely | 2015 | ✅ | typed | 2 | - |
shadow-dom | Shadow DOM | widely | 2020 | ✅ | typed | 11 | - |
shadow-parts | Shadow parts | widely | 2020 | ✅ | typed | 1 | - |
share | navigator.share() | limited | - | ✅ | safe | 2 | - |
shared-storage | Shared storage | limited | - | ✅ | safe , typed | 16 | - |
shared-storage-locks | Shared storage locks | limited | - | ✅ | safe , typed | 5 | - |
shared-workers | Shared worker | limited | - | ✅ | safe , typed | 6 | - |
show-picker-input | showPicker() for <input> | limited | - | ✅ | typed | 1 | - |
show-picker-select | showPicker() for <select> | limited | - | ✅ | typed | 1 | - |
slot | <slot> | widely | 2020 | ✅ | typed | 7 | - |
slot-assign | Imperative slot assignment | newly | 2023 | ✅ | typed | 2 | - |
smil-svg-animations | SMIL SVG animations | widely | 2020 | ✅ | typed | 45 | - |
span | <span> | widely | 2015 | ❌ | - | - | - |
speculation-rules | Speculation rules | limited | - | ✅ | typed | 3 | - |
speech-recognition | Speech recognition | limited | - | ✅ | safe , typed | 32 | - |
speech-recognition-grammar | Speech recognition grammar | limited | - | ✅ | safe , typed | 8 | - |
speech-synthesis | Speech synthesis | widely | 2018 | ✅ | safe , typed | 37 | - |
spellcheck | spellcheck | widely | 2017 | ✅ | typed | 1 | - |
srcset | srcset and sizes | widely | 2017 | ✅ | typed | 4 | - |
starting-style | @starting-style | newly | 2024 | ❌ | - | - | CSS at-rule — use stylelint |
state | :state() | newly | 2024 | ✅ | typed | 11 | - |
storage-access | Storage access | newly | 2023 | ✅ | typed | 5 | - |
storage-buckets | Storage buckets | limited | - | ✅ | safe , typed | 14 | - |
storage-manager | Storage manager | newly | 2023 | ✅ | safe , typed | 6 | - |
streams | Streams | widely | 2022 | ✅ | safe , typed | 44 | - |
structured-clone | structuredClone() | widely | 2022 | ❌ | - | - | Covered in JS builtins (structuredClone) |
style | <style> | widely | 2015 | ✅ | typed | 2 | - |
summarizer | Summarizer | limited | - | ✅ | safe , typed | 14 | - |
supports | @supports | widely | 2015 | ✅ | typed | 1 | - |
svg | SVG | widely | 2020 | ✅ | typed | 247 | - |
svg-discouraged | SVG 1.1 (discouraged) | limited | - | ✅ | typed | 33 | - |
svg-filters | SVG filters | widely | 2015 | ✅ | typed | 176 | - |
tabindex | tabindex | widely | 2018 | ✅ | typed | 1 | - |
table | Tables | widely | 2015 | ✅ | typed | 29 | - |
table-discouraged | Table styling | limited | - | ✅ | typed | 33 | - |
template | <template> | widely | 2015 | ✅ | typed | 1 | - |
text-encoding | Text encoding and decoding | widely | 2020 | ✅ | safe , typed | 21 | - |
text-tracks | Text tracks | widely | 2015 | ✅ | typed | 35 | - |
textarea | <textarea> | widely | 2015 | ✅ | typed | 24 | - |
time | <time> | widely | 2017 | ✅ | typed | 1 | - |
title | <title> | widely | 2015 | ✅ | typed | 1 | - |
title-attr | title (attribute) | widely | 2015 | ✅ | typed | 1 | - |
touch-events | Touch events | limited | - | ✅ | safe , typed | 30 | - |
transferable-streams | Transferable streams | limited | - | ✅ | typed | 3 | - |
transformstream-transformer-cancel | TransformStream transformer cancel() method | limited | - | ✅ | safe | 1 | - |
transitions | Transitions (CSS) | widely | 2015 | ✅ | safe , typed | 9 | - |
translate | translate | newly | 2023 | ✅ | typed | 1 | - |
trusted-types | Trusted types | limited | - | ✅ | typed | 21 | - |
ua-client-hints | User agent client hints | limited | - | ✅ | safe , typed | 7 | - |
url | URL | widely | 2015 | ✅ | safe , typed | 31 | - |
url-canparse | URL.canParse() | newly | 2023 | ✅ | safe | 1 | - |
urlpattern | URLPattern | limited | - | ✅ | safe , typed | 12 | - |
user-activation | User activation | newly | 2023 | ✅ | safe , typed | 3 | - |
user-agent-sniffing | User agent sniffing | widely | 2015 | ✅ | safe , typed | 2 | - |
vibration | Vibration | limited | - | ✅ | safe | 1 | - |
video | <video> | widely | 2015 | ✅ | typed | 61 | - |
view-transitions | View transitions | limited | - | ✅ | safe , typed | 12 | - |
viewport-segments | Viewport segments | limited | - | ✅ | safe , typed | 2 | - |
virtual-keyboard | Virtual keyboard | limited | - | ✅ | safe , typed | 7 | - |
visual-viewport | Visual viewport API | widely | 2021 | ✅ | safe , typed | 11 | - |
web-animations | Web animations | widely | 2020 | ✅ | safe , typed | 49 | - |
web-audio | Web Audio | widely | 2021 | ✅ | safe , typed | 167 | - |
web-bluetooth | Web Bluetooth | limited | - | ✅ | safe , typed | 49 | - |
web-cryptography | Web Cryptography | widely | 2015 | ✅ | typed | 22 | - |
web-locks | Locks | widely | 2022 | ✅ | safe , typed | 6 | - |
web-midi | Web MIDI | limited | - | ✅ | safe , typed | 39 | - |
web-nfc | Web NFC | limited | - | ✅ | safe , typed | 23 | - |
web-otp | WebOTP | limited | - | ✅ | typed | 1 | - |
webauthn | Web authentication | widely | 2021 | ✅ | safe , typed | 16 | - |
webauthn-public-key-easy | Web authentication easy public key access | newly | 2023 | ✅ | typed | 3 | - |
webauthn-signals | Web authentication signal methods | limited | - | ✅ | safe | 3 | - |
webcodecs | WebCodecs | limited | - | ✅ | safe , typed | 103 | - |
webdriver | WebDriver | limited | - | ✅ | safe | 1 | - |
webgl | WebGL | widely | 2015 | ✅ | safe , typed | 163 | - |
webgl-color-buffer-float | WEBGL_color_buffer_float WebGL extension | widely | 2021 | ✅ | safe | 2 | - |
webgl-color-management | Color management for WebGL | newly | 2024 | ✅ | typed | 2 | - |
webgl-compressed-texture-astc | WEBGL_compressed_texture_astc WebGL extension | widely | 2020 | ✅ | safe , typed | 3 | - |
webgl-compressed-texture-etc | WEBGL_compressed_texture_etc WebGL extension | limited | - | ✅ | safe | 2 | - |
webgl-compressed-texture-etc1 | WEBGL_compressed_texture_etc1 WebGL extension | limited | - | ✅ | safe | 2 | - |
webgl-compressed-texture-pvrtc | WEBGL_compressed_texture_pvrtc WebGL extension | limited | - | ✅ | safe | 2 | - |
webgl-compressed-texture-s3tc | WEBGL_compressed_texture_s3tc WebGL extension | limited | - | ✅ | safe | 2 | - |
webgl-compressed-texture-s3tc-srgb | WEBGL_compressed_texture_s3tc_srgb WebGL extension | limited | - | ✅ | safe | 2 | - |
webgl-debug-renderer-info | WEBGL_debug_renderer_info WebGL extension | widely | 2017 | ✅ | safe | 2 | - |
webgl-debug-shaders | WEBGL_debug_shaders WebGL extension | widely | 2020 | ✅ | safe , typed | 3 | - |
webgl-depth-texture | WEBGL_depth_texture WebGL extension | widely | 2015 | ✅ | safe | 2 | - |
webgl-desynchronized | Desynchronized WebGL canvas | limited | - | ✅ | safe | 1 | - |
webgl-draw-buffers | WEBGL_draw_buffers WebGL extension | limited | - | ✅ | safe , typed | 3 | - |
webgl-lose-context | WEBGL_lose_context WebGL extension | widely | 2018 | ✅ | safe , typed | 4 | - |
webgl-multi-draw | WEBGL_multi_draw WebGL extension | limited | - | ✅ | safe , typed | 6 | - |
webgl-oes-draw-buffers-indexed | OES_draw_buffers_indexed WebGL extension | widely | 2022 | ✅ | safe , typed | 9 | - |
webgl-sab | SharedArrayBuffer in WebGL | limited | - | ❌ | - | - | SAB requires COOP/COEP — environment dependent |
webgl2 | WebGL2 | widely | 2021 | ✅ | typed | 229 | - |
webgl2-color-management | Color management for WebGL2 | newly | 2024 | ✅ | typed | 2 | - |
webgl2-desynchronized | Desynchronized WebGL2 canvas | limited | - | ✅ | safe | 1 | - |
webgpu | WebGPU | limited | - | ✅ | safe , typed | 222 | - |
webhid | WebHID | limited | - | ✅ | safe , typed | 27 | - |
webnn | WebNN | limited | - | ✅ | safe , typed | 98 | - |
webrtc | WebRTC | widely | 2020 | ✅ | safe , typed | 155 | - |
webrtc-encoded-transform | WebRTC encoded transform | limited | - | ✅ | safe , typed | 17 | - |
webrtc-sctp | WebRTC SCTP information | newly | 2023 | ✅ | typed | 6 | - |
webrtc-stats | WebRTC statistics | widely | 2020 | ✅ | typed | 25 | - |
websockets | WebSockets | widely | 2015 | ✅ | safe , typed | 22 | - |
webtransport | WebTransport | limited | - | ✅ | safe , typed | 29 | - |
webusb | WebUSB | limited | - | ✅ | safe , typed | 91 | - |
webvr | WebVR | limited | - | ✅ | safe , typed | 64 | - |
webvtt | WebVTT | widely | 2015 | ✅ | safe , typed | 3 | - |
webvtt-cue-alignment | WebVTT cue alignment | limited | - | ✅ | typed | 2 | - |
webvtt-cue-settings | WebVTT cue settings | widely | 2020 | ✅ | typed | 6 | - |
webvtt-regions | WebVTT regions | limited | - | ✅ | safe , typed | 10 | - |
webxr-anchors | Anchors (WebXR) | limited | - | ✅ | typed | 12 | - |
webxr-ar | Augmented reality | limited | - | ✅ | typed | 3 | - |
webxr-camera | Raw camera access for WebXR | limited | - | ✅ | typed | 4 | - |
webxr-depth-sensing | Depth sensing | limited | - | ✅ | typed | 11 | - |
webxr-device | WebXR | limited | - | ✅ | safe , typed | 85 | - |
webxr-dom-overlays | DOM overlays for WebXR | limited | - | ✅ | typed | 2 | - |
webxr-gamepads | Gamepad (WebXR) | limited | - | ✅ | typed | 1 | - |
webxr-hand-input | Hand input | limited | - | ✅ | typed | 13 | - |
webxr-hit-test | Hit test | limited | - | ✅ | safe , typed | 13 | - |
webxr-layers | Layers (WebXR) | limited | - | ✅ | safe , typed | 53 | - |
webxr-lighting-estimation | Lighting estimation | limited | - | ✅ | typed | 9 | - |
wheel-events | Wheel events | limited | - | ✅ | safe , typed | 7 | - |
window | Window | widely | 2015 | ✅ | safe | 33 | - |
window-controls-overlay | Window Controls Overlay | limited | - | ✅ | safe , typed | 7 | - |
window-management | Window management | limited | - | ✅ | safe , typed | 16 | - |
writingsuggestions | writingsuggestions | limited | - | ✅ | typed | 1 | - |
xhr | XMLHttpRequest | widely | 2015 | ✅ | safe , typed | 54 | - |
xml-serializer | XMLSerializer | widely | 2015 | ✅ | safe , typed | 2 | - |
xpath | XPath | widely | 2015 | ✅ | safe , typed | 15 | - |
xslt | XSLT | widely | 2015 | ✅ | safe , typed | 9 | - |
JavaScript Builtins (javascript.*)
- total:
99
- excluded (out-of-scope):
8
- included (in-scope):
91
- mapped:
86
- coverage:
94.5%
Feature ID | Name | Baseline | Year | Mapped | Patterns | Descriptors | Memo |
---|---|---|---|---|---|---|---|
accessor-methods | Accessor methods | limited | - | ✅ | safe | 4 | - |
array | Array (initial support) | widely | 2015 | ✅ | typed | 12 | - |
array-at | Array at() | widely | 2022 | ✅ | typed | 1 | - |
array-by-copy | Array by copy | newly | 2023 | ✅ | typed | 4 | - |
array-copywithin | Array copyWithin() | widely | 2016 | ✅ | typed | 1 | - |
array-fill | Array fill() | widely | 2016 | ✅ | typed | 1 | - |
array-find | Array find() and findIndex() | widely | 2016 | ✅ | typed | 2 | - |
array-findlast | Array findLast() and findLastIndex() | widely | 2022 | ✅ | typed | 2 | - |
array-flat | Array flat() and flatMap() | widely | 2020 | ✅ | typed | 2 | - |
array-from | Array.from() | widely | 2016 | ✅ | safe | 1 | - |
array-fromasync | Array.fromAsync() | newly | 2024 | ✅ | safe | 1 | - |
array-group | Array grouping | newly | 2024 | ✅ | safe , typed | 2 | - |
array-includes | Array includes() | widely | 2016 | ✅ | typed | 1 | - |
array-isarray | Array.isArray() | widely | 2015 | ✅ | safe | 1 | - |
array-iteration-methods | Array iteration methods | widely | 2015 | ✅ | typed | 9 | - |
array-iterators | Array iterators | widely | 2018 | ✅ | typed | 4 | - |
array-of | Array.of() | widely | 2016 | ✅ | safe | 1 | - |
array-splice | Array splice() | widely | 2015 | ✅ | typed | 1 | - |
async-await | Async functions | widely | 2017 | ✅ | - | 0 | Syntax — delegated to es-x |
async-generators | Async generators | widely | 2020 | ✅ | - | 0 | Syntax — delegated to es-x |
async-iterators | Async iterators and the for await..of loop | widely | 2020 | ✅ | - | 0 | Syntax — delegated to es-x |
atomics-pause | Atomics.pause() | newly | 2025 | ✅ | safe | 1 | - |
atomics-wait-async | Atomics.waitAsync | limited | - | ✅ | safe | 1 | - |
bigint | BigInt | widely | 2020 | ❌ | - | - | - |
bigint64array | BigInt64Array | widely | 2021 | ✅ | typed | 2 | - |
date | Date | widely | 2015 | ✅ | typed | 45 | - |
date-get-year-set-year | getYear() and setYear() | limited | - | ✅ | typed | 2 | - |
date-to-gmt-string | toGMTString() | limited | - | ✅ | typed | 1 | - |
error-cause | Error cause | widely | 2021 | ✅ | safe | 2 | - |
escape-unescape | escape() and unescape() | limited | - | ✅ | - | 0 | Legacy functions — delegated to es-x |
explicit-resource-management | Explicit resource management | limited | - | ✅ | safe | 3 | - |
float16array | Float16Array | newly | 2025 | ✅ | safe , typed | 2 | - |
functions | Functions | widely | 2015 | ❌ | - | - | - |
functions-caller-arguments | Function caller and arguments | limited | - | ✅ | - | 0 | Deprecated caller/arguments — self rule |
generators | Generators | widely | 2016 | ❌ | - | - | - |
globalthis | globalThis | widely | 2020 | ❌ | - | - | - |
html-wrapper-methods | HTML wrapper methods | limited | - | ✅ | typed | 14 | - |
intl | Intl | widely | 2017 | ✅ | safe , typed | 12 | - |
intl-display-names | Intl.DisplayNames | widely | 2021 | ✅ | safe | 1 | - |
intl-duration-format | Intl.DurationFormat | newly | 2025 | ✅ | safe | 1 | - |
intl-list-format | Intl.ListFormat | widely | 2021 | ✅ | safe | 1 | - |
intl-locale | Intl.Locale | widely | 2020 | ✅ | safe | 1 | - |
intl-locale-info | Intl.Locale info | limited | - | ✅ | safe , typed | 9 | - |
intl-plural-rules | Intl.PluralRules | widely | 2019 | ✅ | safe | 1 | - |
intl-relative-time-format | Intl.RelativeTimeFormat | widely | 2020 | ✅ | safe | 1 | - |
intl-segmenter | Intl.Segmenter | newly | 2024 | ✅ | safe | 1 | - |
is-error | Error.isError() | limited | - | ✅ | safe | 1 | - |
iterator-methods | Iterator methods | newly | 2025 | ✅ | typed | 11 | - |
iterators | Iterators and the for...of loop | widely | 2015 | ❌ | - | - | - |
javascript | JavaScript (initial core language support) | widely | 2015 | ✅ | typed | 3 | - |
json | JSON | widely | 2015 | ✅ | safe | 3 | - |
json-raw | JSON source text access | limited | - | ✅ | safe | 2 | - |
map | Map (initial support) | widely | 2015 | ✅ | typed | 14 | - |
math-sum-precise | Math.sumPrecise() | limited | - | ✅ | safe | 1 | - |
number | Math and numbers | widely | 2015 | ✅ | safe , typed | 63 | - |
object-hasown | Object.hasOwn() | widely | 2022 | ✅ | safe | 1 | - |
object-object | Object | widely | 2015 | ✅ | safe | 28 | - |
promise | Promise (initial support) | widely | 2015 | ✅ | typed | 9 | - |
promise-allsettled | Promise.allSettled() | widely | 2020 | ✅ | typed | 1 | - |
promise-any | Promise.any() | widely | 2020 | ✅ | typed | 1 | - |
promise-finally | Promise finally() | widely | 2018 | ✅ | typed | 1 | - |
promise-try | Promise.try() | newly | 2025 | ✅ | typed | 1 | - |
promise-withresolvers | Promise.withResolvers() | newly | 2024 | ✅ | typed | 1 | - |
proto | __proto__ | limited | - | ✅ | safe | 1 | - |
proxy-reflect | Proxy and Reflect | widely | 2016 | ✅ | safe | 13 | - |
regexp | Regular expressions | widely | 2015 | ✅ | typed | 21 | - |
regexp-compile | RegExp compile() | limited | - | ✅ | typed | 1 | - |
regexp-escape | RegExp.escape() | newly | 2025 | ✅ | typed | 1 | - |
regexp-static-properties | RegExp static properties | limited | - | ✅ | typed | 6 | - |
resizable-buffers | Resizable buffers | newly | 2024 | ✅ | safe | 1 | - |
serializable-errors | Serializable errors | limited | - | ❌ | - | - | Structured clone semantics — not static-detectable |
set | Set (initial support) | widely | 2015 | ✅ | typed | 13 | - |
set-methods | Set methods | newly | 2024 | ✅ | typed | 7 | - |
shared-memory | SharedArrayBuffer and Atomics | widely | 2021 | ✅ | safe | 13 | - |
stable-array-sort | Stable array sort | widely | 2020 | ❌ | - | - | Semantics not AST-detectable (stable behavior) |
string-at | String at() | widely | 2022 | ✅ | typed | 1 | - |
string-codepoint | String codePointAt() and fromCodePoint() | widely | 2015 | ✅ | typed | 2 | - |
string-includes | String includes() | widely | 2015 | ✅ | typed | 1 | - |
string-matchall | String matchAll() | widely | 2020 | ✅ | typed | 1 | - |
string-normalize | String normalize() | widely | 2016 | ✅ | typed | 1 | - |
string-pad | String padStart() and padEnd() | widely | 2017 | ✅ | typed | 2 | - |
string-raw | String raw() | widely | 2015 | ✅ | typed | 1 | - |
string-repeat | String repeat() | widely | 2015 | ✅ | typed | 1 | - |
string-replaceall | String replaceAll() | widely | 2020 | ✅ | typed | 1 | - |
string-startsends-with | String startsWith() and endsWith() | widely | 2015 | ✅ | typed | 2 | - |
string-trim-startend | String trimStart() and trimEnd() | widely | 2020 | ✅ | typed | 2 | - |
string-wellformed | String isWellFormed() and toWellFormed() | newly | 2023 | ✅ | typed | 2 | - |
strings | String (initial support) | widely | 2015 | ✅ | typed | 21 | - |
symbol | Symbol | widely | 2015 | ✅ | typed | 1 | - |
temporal | Temporal | limited | - | ✅ | safe , typed | 9 | - |
transferable-arraybuffer | Transferable ArrayBuffer | newly | 2024 | ❌ | - | - | Transfer semantics — not static-detectable |
typed-array-iteration-methods | Typed array iteration methods | widely | 2016 | ✅ | typed | 99 | - |
typed-array-iterators | Typed array iterators | widely | 2016 | ✅ | typed | 33 | - |
typed-arrays | Typed arrays (initial support) | widely | 2015 | ✅ | typed | 5 | - |
uint8array-base64-hex | Uint8Array base64 and hex conversion | limited | - | ✅ | safe , typed | 4 | - |
weak-references | Weak references | widely | 2021 | ✅ | safe | 2 | - |
weakmap | WeakMap | widely | 2015 | ✅ | typed | 6 | - |
weakset | WeakSet | widely | 2015 | ✅ | typed | 5 | - |
with | with | limited | - | ✅ | typed | 1 | - |
Last updated on