A weekly selection of the relevant Chromium and Firefox intents
This is my selection of relevant Chromium and Firefox intents (from blink-dev and [email protected], respectively). Updated weekly.
Jump to section: Chromium | Firefox
April 2024
URL.parse
static methodheadingstart
attributeround()
, mod()
, and rem()
functionsDocument-Isolation-Policy
header::scroll-marker
and ::scroll-markers
pseudo-elementsMarch 2024
view-transition-class
propertywritingsuggestions
attributedocument.caretPositionFromPoint
methodtabbed
display mode for tabbed web apps (cont.)<link rel=expect>
element for document render-blockingpageswap
eventFebruary 2024
interesttarget
attribute for buttons and linksreading-order-items
propertySec-CH-UA-Form-Factor
client hint<meta name="app-title">
and document.appTitle
(document subtitle)clonable
option for attachShadow
method, and shadowrootclonable
attribute for <template>
elementsetHTMLUnsafe
and parseHTMLUnsafe
methodsPriority
request headerpicture-in-picture
value for CSS display-mode
media feature@function
)Content-Encoding: zstd
(Zstandard data compression mechanism)paint-order
property for HTML textpicture-in-picture
value for CSS display-mode
media feature:open
and :closed
pseudo-classesline-clamp
propertyzoom
propertypagereveal
eventpageconceal
eventJanuary 2024
text-spacing-trim
propertylight-dark()
functionShadowRoot
clonable
propertynavigation.activation
objectwritingsuggestions
attributetext-box-trim
and text-box-edge
propertiesview-transition-class
property (styling of view transition pseudo-elements)document.caretPositionFromPoint
methodblocking=render
attribute on inline <script>
elementsdisplay: contents
not affecting fosucability'json'
and 'css'
request destinations for JSON and CSS modules::backdrop
pseudo-element from its originating elementDecember 2023
calc-size()
functionfield-sizing
propertycross-fade()
functionmousemove
default actionNovember 2023
unsanitized
option for the navigation.clipboard.read
method<permission>
element (Page-Embedded Permission Control)fetchLater
method@import supports()
rulessnapchanging
event (CSS scroll snap)Speculation-Rules
headernavigation.activation
objectfont-palette
propertycontentVisibilityAuto
option for checkVisibility
method@page
margin boxescontentVisibilityAuto
option for checkVisibility
methodOctober 2023
EditContext
API::spelling-error
and ::grammar-error
pseudo-elements, and spelling-error
and grammar-error
values for text-decoration-line
::selection
and ::highlight
pseudo-elementsmask-*
propertiesruby
, ruby-base
, and ruby-text
values for CSS display
propertyscrollbar-color
and scrollbar-width
properties<transform-function>
and <transform-list>
syntax for registered custom propertiespow()
, sqrt()
, hypot()
, log()
, and exp()
functionsURL.canParse
methodpeformance.measureUserAgentSpecificMemory
method"scope_extensions"
memberPriority
request header:dir()
pseudo-class<source media>
attributeHTMLSelectElement
showPicker
method<image>
syntax for registered custom propertiesSeptember 2023
firstrender
eventscrollMargin
propertyname
attribute on <details>
elementsfullscreen
option for window.open
methodexportid
attribute (exporting IDs from shadow roots for cross-root ARIA)<hr>
elements inside <select>
elementsshowPicker
method for HTML <select>
elementsxywh()
and rect()
for CSS clip-path
propertydynamic-range-limit
propertyscrollMargin
property:visited
links historySpeculation-Rules
header (cont.)Sec-CH-UA-Form-Factor
Header (client hint)August 2023
from
keyword)form-sizing
propertySec-CH-Prefers-Reduced-Transparency
header (client hint)word-break: auto-phrase
value (more natural line breaking for Japanese)<permission>
element (Page-Embedded Permission Control):user-valid
and :user-invalid
pseudo-classesscripting
media featuretext-spacing-trim
propertystuck
)scripting
media featurecrossorigin
attribute for SVG <image>
and <feImage>
elementshasUAVisualTransition
property for popstate
and navigate
eventssnapchanged
event<search>
elementblocking="render"
attributevertical-rl
, vertical-lr
) for form control elements<geometry-box>
in CSS clip-path
property valuecap
and rcap
unitsfloat
, clear
, and resize
propertiesJuly 2023
inverted-colors
media featurefetchLater
methodprefers-reduced-transparency
media featureSec-CH-Prefers-Reduced-Transparency
headerClear-Site-Data: "*"
header (clear all storage targets)"tab_strip"
member and "display_override": ["tabbed"]
(tabbed web apps)Content-Encoding: zstd
(Zstandard data compression mechanism)text-autospace
propertyCache-control: no-store
headerprefers-reduced-transparency
media featurefont-variant-emoji
propertystroke-box
, content-box
, and border-box
values for CSS transform-box
propertyword-break: auto
value (more natural line breaking for Japanese)June 2023
"unload"
feature:visited
links historyFileSystemObserver
APItext-wrap: pretty
keyword@starting-style
ruleContent-Encoding: zstd
(Zstandard data compression mechanism)customElements.getName
methodcustomElements.getName
methodscheduler.yield
methodMay 2023
@scope
rule'long-animation-frame'
performance entry type"scope_extensions"
memberunload
eventscroll-start
property<details>
elementsApril 2023
overlay
propertydisplay
propertydisplay
property (new two-value syntax)scheduler.yield
methodMarch 2023
v
flag for HTML pattern
attributescrollend
event type<meta name="subtitle">
and document.subtitle
)font-size-adjust
property (new syntax)requestStorageAccessFor
method for First-Party Setsfont-palette
property:lang
pseudo-classdisplay
and content-visibility
in animationspopover=hint
attribute valuetext-box-trim
propertyFebruary 2023
text-wrap
propertyoverflow-inline
and overflow-block
media featureslinear()
easing functionupdate
media featurefont-variant-position
propertylinear()
easing functiontext-wrap: balance
keywordtop-layer
property:initial
pseudo class"battery"
tokenJanuary 2023
animation-composition
propertyuser-select: contain
keywordunload
permission (cont.)font
shorthand<dialog>
initial focus algorithmabs()
and sign()
functions:nth-child()
and :nth-last-child()
pseudo-classes (An+B of S
)baseline-source
propertyrex
, rch
, ric
, and rlh
unitsPriority
request headerDecember 2022
sin()
, cos()
, tan()
, asin()
, acos()
, atan()
, atan2()
)baseline-source
propertyPointerEvent
deviceId
property for mult-pen inkingfont-variant-alternates
property and @font-feature-values
ruledisplay
and content-visibility
in animationsNovember 2022
initial-letter
propertyinitial-letter
propertyweb-share
permission"user_preferences"
field (allows specifying dark mode colors) (updated)October 2022
scheduler.yield
methodSpeculation-Rules
headerAccept-Language
header and navigator.languages
propertyhyphenate-limit-chars
property"launch_handler"
)URLPatternList
color()
and color-mix()
functions, and other Color Level 4 additionshyphenate-limit-chars
propertyinitial-letter
propertylh
unitPendingBeacon
)last baseline
alignment for flex/grid itemsSeptember 2022
TrustedHTML
fromLiteral
methodURLPattern
ignoreCase
option@supports font-tech()
and @supports font-format()
rulesunload
permissionlast baseline
alignment for flex/grid itemsSec-CH-Prefers-Reduced-Motion
header (client hint)lh
unitunload
permissionaria-brailleroledescription
and aria-braillelabel
attributesAugust 2022
tech()
function for CSS @font-face
src
descriptorAudioContext
setSinkId
methodcontentvisibilityautostatechanged
eventrequestStorageAccessForSite
APIic
unitpopup
attribute)July 2022
URLPattern
ignoreCase
optionrestrict-properties
valueborderless
display mode for installed web apps on desktopNavigateEvent
scroll
method"user_preferences"
field (allows specifying dark mode colors) (cont.)fetch()
upload streamingcontentvisibilityautostatechanged
eventoverflow
property for replaced elementsJune 2022
Sec-CH-Viewport-Height
)import.meta.resolve
functionrenderBlockingStatus
property for performance resource entriesoverflow
property for replaced elementsrequestPermission
function for DeviceOrientationEvent
and DeviceMotionEvent
sin()
, cos()
, tan()
, asin()
, acos()
, atan()
, atan2()
)PendingBeacon
)"launch_handler"
member) (cont.):lang()
pseudo-class level 4 extension (argument lists and language range matching)May 2022
tabbed
display mode):modal
pseudo-classblocking=render
attribute for <link>
and <script>
elementsobject-view-box
property:has()
pseudo-classfocusgroup
attributeunload
featurePendingBeacon
APIElement
isVisible
method<form rel>
attributeoverflow-clip-margin: <visual-box>
values"user_preferences"
field (cont.)April 2022
web app manifest "launch_handler"
member) (cont.)Element
isVisible
methodfocusgroup
attributeAbortSignal.timeout static
method"gamepad"
token103 Early Hints
on navigation responses"bluetooth"
tokenSerialPort
forget
method"file_handlers"
fieldSec-CH-Viewport-Height
header (viewport height client hint)March 2022
@scope
at-ruleinnerText
property and adjust
methodhidden=until-found
attribute and beforematch
eventfont-palette
property and @font-palette-values
at-ruleSec-CH-Save-Data
client hintobject-view-box
and object-overflow
propertiesfetchpriority
attribute, and priority
option for fetch
)February 2022
USBDevice
forget
methodEvent
path
methodHIDDevice
forget
methodhwb()
color functionJanuary 2022
AbortSignal.timeout
static methodmakeReadOnly
method (for locking NFC tags)mix-blend-mode: plus-lighter
valuefocusgroup
attributeid
propertyDecember 2021
mix-blend-mode: plus-lighter
valueHTMLInputElement
showPicker
method@layer
rule (Cascade Layers)"user_preferences"
field (allows specifying dark mode colors)November 2021
<canvas>
blocking=render
attribute for <link>
and <script>
elements'popup'
option (window feature) for window.open()
AudioContext
outputLatency
propertyHTMLInputElement
showPicker
methodOctober 2021
structuredClone
functionforced-color-adjust: preserve-parent-color
valueauto
keyword for CSS contain-intrinsic-size
propertyonly
keyword for CSS color-scheme
property"launch_handler"
member"translations"
memberdynamic-range
and video-dynamic-range
media features (HDR)translate
, scale
, and rotate
properties (individual transforms)keyboard-map
feature policysec-ch-
on all Client Hintsonly
keyword for CSS color-scheme
property103 Early Hints
on navigation responses (cont.)font-synthesis
propertyRange
header values"scope_extensions"
field"handle_links"
fieldSeptember 2021
"id"
fieldHTMLScriptElement
supports
methodFocusableMediaStreamTrack
subclass (Conditional Focus)FocusableMediaStreamTrack
subclass (Conditional Focus)renderpriority
attributefont-synthesis
property<details>
elementsspeak-as
descriptor for CSS @counter-style
rule<script type="speculationrules">
) (cont.)importance
attribute (Priority Hints) (cont.)"id"
fieldHTMLScriptElement
supports
methodHTMLScriptElement
supports
methodAugust 2021
URLPattern
APIreportError
functionmath
generic font familyprefers-contrast
media feature"launch_handler"
member)July 2021
Service-Worker-Subresource-Filter
headerpreferCurrentTab
option for getDisplayMedia
method (Screen Capture)display-capture
permissionURLPattern
APIspeak-as
descriptor for CSS @counter-style
rule@counter-style
rules in shadow treesscrollbar-gutter
property"note_taking"
fieldUser-Agent
stringscheduler.postTask
method)June 2021
supports <font-technology>
for the CSS src
descriptor<meta name="theme-color" media>
attribute"id"
fieldSec-CH-Prefers-Color-Scheme
header (Client Hints)colorSpace
option for canvas context)accent-color
propertyAbortSignal
abort
static method:autofill
pseudo-classMay 2021
<script type="speculationrules">
)noplaybackrate
token for the HTML media element controlslist
attributearia-touchpassthrough
attribute103 Early Hints
on navigation responsesSec-CH-Prefers-Color-Scheme
header (Client Hints)fetch()
upload streaming (cont.):has()
pseudo-classsize-adjust
descriptorcrypto.randomUUID
methodApril 2021
SameParty
cookie attribute (cont.)Service-Worker-Subresource-Filter
header:playing
and :paused
pseudo-classescontain-intrinsic-size: auto
valueMarch 2021
inert
attribute"note_taking"
and "new_note_url"
fieldsGravitySensor
APICritical-CH
response header<link rel="icon" media>
attributedocument.prerendering
propertyFebruary 2021
advance-override
descriptor@counter-style
at-rule103 Early Hints
on navigation responsesSameParty
cookie attributeaccent-color
propertyblob:
and filesystem:
URLs"capture_links"
member for web app manifest)January 2021
:focus-visible
in the user-agent style sheetsignal
option for addEventListener
method (AbortSignal)GravitySensor
APIStaticRange
constructor<popup>
elementaspect-ratio
propertyscheduler.postTask
method for main-thread scheduling (cont.)SameParty
cookie attributefetch()
upload streaming::spelling-error
and ::grammar-error
pseudo-elements, and spelling-error
and grammar-error
values for text-decoration-line
performance.measureMemory
methodDecember 2020
filter
property for SVG elements (filter functions):link
, :visited
, and :any-link
pseudo selectors for <link>
elements"capture_links"
member for web app manifest)infinity
and NaN
values in CSS calc()
::file-selector-button
pseudo-elementborder-start-start-radius
, border-start-end-radius
, border-end-start-radius
, and border-end-end-radius
propertiesdata:
URLs"display_override"
fieldoverflow: clip
value and overflow-clip-margin
propertydisclosure-open
and disclosure-closed
keywords for the CSS list-style-type
propertylist-style-type
and ::marker
support on <summary>
elementNovember 2020
"display-capture"
permissionbeforematch
event and CSS content-visibility: hidden-matchable
value (cont.)::target-text
pseudo-elementsignal
option for addEventListener
method (AbortSignal)@counter-style
at-rule<meta name="battery-savings">
tag (cont.)click
, contextmenu
, and auxlick
as instances of PointerEvent
October 2020
rel="noopener"
for <a target="_blank">
elements:not()
pseudo-classSupports-Loading-Mode
response header (prerendering opt-in):dir()
pseudo-classhyphens: auto
value on Windows:is()
and :where()
pseudo-classesscrollbar-color
and scrollbar-width
propertiesclip-path: path()
valuesprefers-contrast
media feature::target-text
pseudo-elementgetCurrentBrowsingContextMedia
methodaspect-ratio
propertySeptember 2020
Permissions-Policy
headerscheduler.postTask
method for main-thread scheduling (cont.)text-decoration-thickness
and text-underline-offset
properties, and text-underline-position: from-font
valueperformance.measureMemory
method (cont.)navigator.scheduling.isInputPending
methodascent-override
, descent-override
, and line-gap-override
font descriptorsCritical-CH
response headerreleased
propertyAugust 2020
overflow: clip
value and overflow-clip-margin
property<select>
elementPermissions-Policy
headerquotes: auto
valuebeforematch
event and CSS content-visibility: hidden-matchable
value<meta name="battery-savings">
tagforce-load-at-top
document policy)<meta name="battery-savings">
tagSharedArrayBuffer
gated behind COOP/COEP (on Android)July 2020
Content-Encoding: jxl
value (JPEG XL)strict-origin-when-cross-origin
as default referrer policyDocument-Policy
header@font-face
descriptors for overriding font metrics (e.g., ascent-override
)web-share
permissionreplaceChildren
method::marker
pseudo-element'visibility-state'
performance entriesFetchEvent
handled
property (promise)quotachange
event (storage pressure)June 2020
getDevices
and watchAdvertisements
methodsclipboard-read
and clipboard-write
policies<link rel="media-feed">
)HTMLMediaElement
preservesPitch
propertyPictureInPictureEvent
pictureInPictureWindow
propertyscrollbar-gutter
propertycolor-mix()
functioncounter-set
property"display-override"
fieldcontent-visibility
propertyMay 2020
attr()
function Level 4 extensioncolor-scheme
propertyperformance.measureMemory
method (cont.)attr()
function Level 4 extensionrow-gap
and column-gap
properties in Flexbox Layoutbeforematch
eventApril 2020
forced-color-adjust
property)watchAdvertisements
method@property
at-rulerendersubtree
attribute (cont.)navigator.getInstalledRelatedApps
API on Windowstext-decoration-thickness
and text-underline-offset
properties, and text-underline-position: from-font
valueMarch 2020
revert
keywordlch()
and lab()
functions (CIE LAB color functions)page
property (named pages) and page-orientation
descriptoraspect-ratio
propertyappearance
property-webkit-appearance: auto
valueoff
and noscroll
values for the <iframe scrolling>
attributeperformance.measureMemory
methodFebruary 2020
getDevices
method:state()
pseudo-classdurability
property for IndexedDB transactions (durability hint)<iframe disallowdocumentaccess>
attributesuggestion
, mark
, and comment
roles and aria-description
attribute (ARIA annotations)contain-intrinsic-size
propertyprefers-reduced-data
media featurespanning
media feature and fold-top
/fold-left
/fold-width
/fold-height
environment variablesfont-display: optional
without relayoutrawValue
property for <input>
elementsscheduler.postTask
method for main-thread schedulingJanuary 2020
<input type="time">
with a reversed range (min
> max
)requestAnimationFrame
method for <video>
elementsrow-gap
and column-gap
properties in Flexbox Layoutcolor-scheme
property and "color-scheme"
<meta>
valueSec-CH-UA-*
headers (Client Hints)User-Agent
header valuetimezonechange
eventDecember 2019
buffered
option for Performance Observersubmitter
property for submit
eventsNovember 2019
contentBoxSize
, borderBoxSize
, and devicePixelContentBoxSize
properties<a hreftranslate>
attributeSec-Fetch-Dest
request headergetVideoPlaybackQuality
method)ActiveText
, Field
, and FieldText
values (system color keywords)image-orientation
propertyspatialNavigationSearch
method (part of CSS Spatial Navigation)navigator.getInstalledRelatedApps
API:focus-visible
pseudo-classintrinsic-size
propertyOctober 2019
ElementInternals
objectlatencyHint
attribute for HTML media elementsannotation-attribution
, annotation-commentary
, annotation-presence
, annotation-revision
, annotation-suggestion
rolesCanvas
and Text
system color keywordsstrict-origin-when-cross-origin
as new default for Referrer Policy:state()
pseudo-classrendersubtree
attribute and CSS content-size
propertyrequestAnimationFrame
method for <video>
elements@supports selector()
functionwidth
and height
attributeslist-style-type
propertyline-break: anywhere
valueoverflow-wrap: anywhere
valueSeptember 2019
font-optical-sizing
propertyrendersubtree
attributenavigator.screen.requestDisplays
method)http:
to https:
)navigation-controls
media featureEditContext
APIwidth
and height
attributesautofocus
attribute on any focusable HTML/SVG elementrelaxedDurability
option for the IndexedDB transaction
method (controls flushing to disk)August 2019
navigator.scheduling.isFramePending
methodCompressStream
and DecompressStream
APIscontent-size
propertySecure
cookies in third-party contextsJuly 2019
scheduler.postTask
method for main-thread schedulingdocument-access
policynavigator.scheduling.isInputPending
method (early detection of input events)buffered
option for PerformanceObserver
observe
methodnavigator.getInstalledRelatedApps
API (cont.)June 2019
overscroll-behavior-inline
and overscroll-behavior-block
propertiescontent
propertymin()
, max()
and clamp()
functionsintegrity
attribute on <link rel="preload">
elementsfont-size: xxx-large
value<std-toast>
element (toast notification)@property
at-ruleperformance.measureMemory
method)<std-switch>
element (toggle switch control)getAvailability
methodMay 2019
jump-start
, jump-end
, jump-none
, and jump-both
keywords for the CSS steps()
easing functionCross-Origin-Opener-Policy
response headerSameSite=Lax
by default)focus-without-user-activation
policylowLatency
option for '2d'
and 'webgl'
canvas contexts (cont.)color-scheme
propertyenterkeyhint
attributeImageBitmap
rendering context for OffscreenCanvas
'formdata'
event typeHTMLFormElement
requestSubmit
methodscroll-snap-stop
propertypointerrawmove
event typeAnimation
pending
propertyprefers-color-scheme
media featureApril 2019
IDBTransaction
commit
methodexecution-while-out-of-viewport
and execution-while-not-rendered
features (enables freezing hidden iframes)<a hrefTranslate>
attribute (cont.)white-space: break-spaces
valueimportance
attribute (Priority Hints) (cont.)Blob
text
, arrayBuffer
, and stream
methodsSec-Fetch-Mode
, Sec-Fetch-Site
, and Sec-Fetch-User
request headersAnimation
constructor (Web Animations)March 2019
:picture-in-picture
pseudo-class<link rel="icon">
)desynchronized
option for 2D canvas context (was lowLatency
)document-domain
feature<video playsinline>
attributeoutline-color: invert
valuebackdrop-filter
propertycontent
propertyline-break: anywhere
valueFebruary 2019
unoptimized-images
and oversized-images
featuresPointerEvent
getPredictedEvents
method<script type="importmap">
)January 2019
transitionrun
, transitionstart
, and transitioncancel
)<video autoPictureInPicture>
attribute<meta name="supported-color-schemes">
elementCross-Origin-Resource-Policy
headerSec-CH-UA-*
headers (Client Hints)importance
attribute (Priority Hints)Sec-CH-Lang
header (Client Hints)navigator.getInstalledRelatedApps
APIfont-optical-sizing
property<img elementtiming>
attribute'layoutjank'
performance entriesimagesrcset
and imagesizes
attributes for the <link>
element (selectively preloading images)prefers-reduced-motion
media featureprefers-color-scheme
media featureDecember 2018
document.featurePolicy
API (for policy introspection)stale-while-revalidate
Cache-control
extension::part
pseudo-element (CSS Shadow Parts)lowLatency
option for '2d'
and 'webgl'
canvas contexts (cont.)GamepadButton
touched
propertyPerformanceObserver.supportedEntryTypes
propertyNovember 2018
<a hrefTranslate>
attributedocument-domain
featureIntl.ListFormat
APIOctober 2018
FetchEvent
Worker Timing (measuring the performance of service workers)colorSpace
and pixelFormat
options for canvas contexts (canvas color management)font-display
descriptor for @font-feature-values
(setting the default font-display
value for a font family)lowLatency
option for '2d'
and 'webgl'
canvas contexts'layoutjank'
performance entry (Performance API)navigator.getDisplayMedia
method (Screen Capture):host()
, etc.)September 2018
PointerEvent
getPredictedEvents
methodnavigator.isProtocolHandlerRegistered
methodreport-to
directive<img elementtiming>
attribute)TextEncoderStream
and TextDecoderStream
APIsscript-src-attr
, script-src-elem
, style-src-attr
, and style-src-elem
directivesqueueMicrotask
functionAugust 2018
prefersNavigationBar
option for Fullscreen APIpointerrawmove
event typeintrinsicsize
attribute (for images and videos)animations
feature'feature-policy-violation'
report type)<a hreftranslate>
attributelazyload
featureJuly 2018
<portal>
element for seamless navigations between sites or pagesdocument.policy
)queueMicrotask
functionpostMessage
methodsync-script
feature (for disabling parser-blocking script execution)stale-while-revalidate
directive for HTTP Cache-Control
headerleft
and right
values for the CSS text-underline-position
propertyJune 2018
gamepadbuttondown
, gamepadbuttonup
, gamepadbuttonchange
, and gamepadaxismove
eventsElement
toggleAttribute
methodstale-while-revalidate
directive for HTTP Cache-Control
headerviewport-fit
descriptor for <meta name="viewport">
'unsafe-hashes'
source expressionnavigator.keyboard
and keyboardchange
event)type: 'module'
option for Worker
constructor)navigator.getDisplayMedia
method (Screen Capture)requestPictureInPicture
method)Request
isHistoryNavigation
propertyReportingObserver
APIMay 2018
Sec-Metadata
request headerTextEncoderStream
and TextDecoderStream
APIs<script referrerpolicy>
attributerequestPictureInPicture
method)trackVisibility
and isVisible
properties)<virtual-list>
element (layered API)AnimationEvent
pseudoElement
property (CSS Animations)April 2018
'same-origin'
as the default credentials mode for fetch()
(the previous default was 'omit'
)Network-RTT
and Network-BW
request headers (network quality estimates)importance
attribute)overflow
shorthand (accepts two values)prefersNavigationBar
option for Fullscreen APInavigator.keyboard
and keyboardchange
event)'event'
performance entries)customElements.upgrade
methodMarch 2018
button
property values 3
and 4
)style
option for customElements.define
method (for providing a custom element’s default styles)formdata
event type (Form Participation API)TransformStream
constructorconic-gradient()
functionnavigate-to
directiveAccept-CH-Lifetime
response header::part()
and ::theme()
pseudo-elements)February 2018
:focus-visible
pseudo-class<slot>
elements in the flat treesrcset
and imgsizes
attributes on <link rel="preload" as="image">
elementsmodulepreload
link relationinputmode
attribute::first-letter
pseudo-elementsCSSStyleSheet
constructor):is()
pseudo-classJanuary 2018
x
unit (synonym for dppx
)justify-items: legacy
valuejustify-items: legacy
value<script integrity>
) to support validating a resource’s signature”video.requestPictureInPicture()
)#
in data URL body (the first #
will be treated as the start of the fragment)row-gap
, column-gap
, and gap
properties (grid-row-gap
/etc. become aliases)calc()
in media queriesinput
event when a range
or file
<input>
element is activated”takeRecords
method<iframe allow>
attribute)sync-xhr
featureinput
event when a (mutable) checkbox is clicked”HTMLAnchorElement
relList
propertykeepalive
optionDecember 2017
display: contents
value:matches()
pseudo-classaccelerometer
, gyroscope
, magnetometer
featuresAbortController
and AbortSignal
)autoplay
feature:any-link
pseudo-class<img decoding>
attributesaveData
propertyNovember 2017
:any-link
pseudo-classautoplay
featurepositionAlign
and lineAlign
propertiesbutton
property values 3
and 4
)AudioWorklet
interfaceautocapitalize
attribute on <form>
and contenteditable
elementscache
option (also a property on Request
objects)line-height-step
propertymodulepreload
link relationEventTarget
constructorpreventScroll
option for focus APIsOctober 2017
<iframe delegatestickyuseractivation>
attibutetransform-box
propertytext-decoration-skip-ink
property (and remove text-decoration-skip: ink
value)<slot>
elements (assigned nodes inherit style)keepalive
optionsaveData
property<img async>
attribute'unsafe-hashed-attributes'
source expressionSeptember 2017
<textarea autocomplete>
and <select autocomplete>
attributesoverflow-wrap: break-spaces
valueimport()
syntax for dynamic importsallowedActivationDelegation
property)click
) to disabled form controls”applyConstraints
methodformatToParts
methodfinally
methodscroll-boundary-behavior
propertynavigator.requestKeyboardLock
method)focus
methodAugust 2017
navigator.deviceMemory
propertyhistory.index
propertyhttp://localhost
as a secure context”q
unittimeOrigin
propertyvisibility: collapse
)July 2017
s
flag for JavaScript regular expressionsperformance.timeOrigin
propertydecode
methodDevice-Memory
headerExpect-CT
headerimport()
syntax for dynamic importsJune 2017
beforeprint
and afterprint
events<time>
element<data>
elementsort
methodvisibility: collapse
)<script type="module">
Clear-Site-Data
headergetPhotoSettings
methodReportingObserver
API<body>
to <html>
”'same-origin'
, 'strict-origin'
, and 'strict-origin-when-cross-origin'
valuesMay 2017
getAttributeNames
method<iframe csp>
attribute)replace
methodas
value for preload
linksnavigator.webdriver
propertyreport-to
directivedownlink
, rtt
, and effectiveType
propertiesnavigator.storage.estimate
methodX-Frame-Options: SAMEORIGIN
(check all ancestor frames)PerformancePaintTiming
interface)password
propertymessageerror
eventformData
methodApril 2017
Device-Ram
header and navigator.deviceRam
APIscroll-behavior
property and behavior
option for scroll APIs (enables smooth scrolling)reserve
methodgetCost
and getBudget
methodsMarch 2017
decode
methodpipeTo
and pipeThrough
methodstransform-box
property<script integrity>
)DataTransfer
constructornavigator.getInstalledRelatedApps
APIframes()
timing function:focus-within
pseudo-classscript-sample
property in CSP violation reportsconic-gradient()
notationscreen.colorDepth
, screen.pixelDepth
, and the CSS color
media featuresample
property for CSP reportsFebruary 2017
offset-path
propertycontrolsList
property (for customizing native media controls)place-*
(shorthand) propertiesallow-top-navigation-by-user-activation
keyword for <iframe sandbox>
inert
attribute<video muted autoplay>
when invisible (on Android)origin
property (self.origin
)data:
URLsNetwork-RTT
and Network-BW
headers (Network Information API extension)January 2017
color-gamut
media featurefont-display
propertygetCoalescedEvents
methodline-height-step
propertymargin-*
properties)tangentialPressure
and twist
propertiesdisplay: flow-root
valueExpect-CT
headerdocument.rootScroller
propertycolorSpace
property)December 2016
rel="prefetch"
in Link
headerClipboardEvent
constructor*-size
properties)scroll-boundary-behavior
propertypurpose
field (for icons)November 2016
pipeTo
and pipeThrough
methods<iframe allowpaymentrequest>
attributegetCoalescedEvents
methodtext-decoration-*
properties::placeholder
pseudo-elementcaret-color
propertycanMakeActivePayment
methodvisibilitychange
event on document unloading”nextHopProtocol
propertyworker-src
directiveOctober 2016
<link referrerpolicy>
attributeposition: sticky
valueisComposing
propertyshape
media feature<canvas>
'referrer'
directivedisplay: contents
valuePresentationConnection.url
propertysystem-ui
generic font familyimage
property (“a large image as part of the content of a notification”)Referrer-Policy
headerSeptember 2016
disposition
propertyoverscroll-action
propertypinch-zoom
value for CSS touch-action
propertyMediaStream
constructortext-decoration-skip
property (and default to ink
value)new Document()
devicechange
eventhyphens
propertyrequestAnimationFrame
occurs”August 2016
auxclick
event typeimage
propertyonce
option for addEventListener
methoddataset
API on SVG elementsserviceworker
link relation-webkit-image-set
functionJuly 2016
prepend
/append
/before
/after
/replaceWith
methodspan-up
/pan-down
/pan-left
/pan-right
values for CSS touch-action
property (follow up)Node.getRootNode
method (was Node.rootNode
)touched
and pose
properties)BroadcastChannel
APIrequire-sri-for
directivePushSubscription.options
property"auxclick"
event type (non-primary button click)navigator.vibrate
in cross-origin iframes”pan-up
/pan-down
/pan-left
/pan-right
values for CSS touch-action
propertyJune 2016
"install"
event for Web App Manifestthe text-size-adjust
property<audio>
/<video>
(“WebRTC streaming of prerecorded content”)Referrer-Policy
HTTP header<video autoplay muted>
)transferSize
/encodedBodySize
/decodedBodySize
propertiesMay 2016
<body>
do not block paint”nav-up
, nav-down
, nav-left
, nav-right
propertiesu
flag to <input pattern>
attribute”allow-presentation
token for <iframe sandbox>
attributeReadableStream
response body in the Response
constructor”<iframe>
saction
/vibrate
attributes on Notification
instancesasync
and await
)#RRGGBBAA
and #RGBA
)requestAutocomplete
methodfont-variant-numeric
propertynavigator.storage.persist
and .persisted
methods)April 2016
Clear-Site-Data
HTTP headercontain
property)hyphens
propertyImageBitmap.close
methodunsafe-dynamic
CSP source expressionIDBKeyRange.includes
methodnavigator.storage.estimate()
)ImageBitmapOptions
-webkit-appearance: none
for <meter>
and <progress>
elementsHTMLMediaElement.srcObject
for MediaStreamsuser-select: none
(unprefixed)CanvasRenderingContext2D.filter
property)Node.isConnected
propertyMarch 2016
Request.referrerPolicy
propertyKeyboardEvent.key
propertySameSite
attribute for cookiesHTMLMediaElement.srcObject
for MediaStreamsdocument.open
and document.write
during unload”"visibilitychange"
event on document unloading”<script type="module">
.rootNode
propertyFebruary 2016
referrerpolicy
attributeMediaDevices
'devicechange'
event'beforeunload'
dialogs”@apply
ruleEventListenerOptions.passive
<canvas>
(captureStream
method )font-variant-caps
propertyInputEvent
interface:dir()
pseudo-classImageBitmap
options"serviceworker"
link relationshipDOMSettableTokenList
into DOMTokenList
”break-after
, break-before
, break-inside
(generic breaking control)HTMLMediaElement.play()
retuns a promise”January 2016
"notificationclose"
event"preload"
link relationshipAccept-encoding: br
on HTTPS connection)ImageBitmap
and createImageBitmap
methodHTMLMediaElement
column-fill
propertyFetchEvent.clientId
and Clients.get(id)
for Service WorkerEventListenerOptions.passive
{add,remove}EventListener
to accept EventListenerOptions
”December 2015
inverted-colors
media featurePushEvent.data
property)i
modifier for attribute selectorstoBlob
methodNovember 2015
HTMLMediaElement.disableRemotePlayback
addEventListener
/removeEventListener
non-optional arguments<link>
and <iframe>
URLSearchParams
"noopener"
link relationOctober 2015
"navigate"
mode in fetch
requestsaddEventListener
to accept EventListenerOptions
”WindowClient.navigate
method for service workersSeptember 2015
NodeList
position: sticky
data:
and blob:
schemes in Fetch API”font-display
stale-while-revalidate
Cache-control extensionApril 2024
@scope
rule@top-left
)from
keyword)zoom
property and Element
currentCSSZoom
propertytextInput
eventMarch 2024
URL.parse
static methodCustomStateSet
interface)Selection
direction
property and getComposedRanges
method, and selections across shadow boundariesARIAMixin
interface)readText
methodFebruary 2024
align-content
property on block containersuser-find
propertyJanuary 2024
Link
headers with rel=preload
or rel=modulepreload
in HTTP Early Hints responsescontent-visibility
propertyDecember 2023
xywh()
and rect()
basic shapesoffset-position
and offset-path
propertiescontent-box
and stroke-box
values for CSS transform-box
propertyNovember 2023
popover
attribute<hr>
elements inside <select>
elements._internals.states
property for exposing custom element states (CustomStateSet
)October 2023
HTMLSelectElement
showPicker
method:has()
pseudo-classtext-wrap: balance
valuehanging
and each-line
keywords for the text-indent
CSS propertyloading=lazy
attribute on <iframe>
elementslh
and rlh
unitslight-dark()
color functionSeptember 2023
zoom
property::backdrop
from its originating element (e.g., <dialog>
)attr()
fallbackOrigin-Agent-Cluster
headertext-wrap: balance
keywordAugust 2023
:first
pseudo-classfont-synthesis-position
propertySec-GPC
header):has
selector<search>
elementround()
, mod()
, rem()
, pow()
, sqrt()
, hypot()
, log()
, exp()
, abs()
, and sign()
functionsJuly 2023
text-transform: math-auto
keywordmath-style
and math-depth
properties, and font-size: math
keywordJune 2023
URL.canParse
functionMay 2023
animation-composition
propertymodulepreload
link relationdirname
attribute (submitting element directionality)@import supports()
rulesNaN
/infinity
in calc()
April 2023
@import
rules in CSSinverted-colors
media feature:lang()
selector (incl. wildcard matching)March 2023
color-mix()
function<discard>
elementscripting
media feature:nth-child()
and :nth-last-child()
pseudo-classesprefers-reduced-transparency
media featurelab()
, lch()
, oklab()
, oklch()
, color()
)read
and readText
with user confirmationinert
attributeforced-color-adjust
propertylinear()
easing functionFebruary 2023
lock
method on Android and Windows tabletJanuary 2023
autocapitalize
attributepage
property (named pages)December 2022
'unsafe-hashes'
source expressionpage
property (named pages)scrollend
eventNovember 2022
October 2022
width
and height
attributes for HTML <source>
elementsscript-src-elem
, script-src-attr
, style-src-elem
, style-src-attr
directivesfont-variant-emoji
propertyfont-palette
property and @font-palette-values
at-ruleSeptember 2022
contain-intrinsic-size
property and its longhandsElementInternals
objectAugust 2022
July 2022
width
and height
attributes on <source>
elementsscript-src-elem
and script-src-attr
directivesfontKerning
propertyanimation-composition
propertyJune 2022
May 2022
TransformStream
and ReadableStream
pipeThrough
methodApril 2022
sv*
), large (lv*
), dynamic (dv*)
, and logical (vi
, vb
) viewport unitsprefers-contrast
media featureHTMLInputElement
showPicker
methodTransformStream
and ReadableStream
pipeThrough
methodMarch 2022
content-visibility: hidden
valueJanuary 2022
hyphenate-character
property<dialog>
elementDecember 2021
scrollbar-gutter
propertyhyphenate-character
propertyd
propertyOffscreenCanvas
interfaceSameSite=Lax
cookie attribute by defaultNovember 2021
hwb()
function (HWB Colors)reversed()
functional notation for the CSS counter-reset
propertyOctober 2021
size
property in @page
rulesinputmode
attribute on desktopinput-security
propertystructuredClone
functionSeptember 2021
enterkeyhint
attributesize
property for @page
<input type=datetime-local>
on desktopSelectedItem
and SelectedItemText
system colorssmooth
and pixelated
values for the CSS image-rendering
propertyShadowRoot
delegatesFocus
property@layer
at-ruleAugust 2021
"HTTPS"
DNS resource record (HTTPS RR)reportError
functionavoid-page
and avoid-column
values for CSS break-inside
propertysystem-ui
generic font family namedisabledFeatures
static method for custom element classesJuly 2021
accent-color
propertyassign
method for <slot>
elementsize-adjust
descriptor and
extended syntax of the font-size-adjust
propertyJune 2021
font-synthesis: small-caps
valuecontent: none
on elementscontent: none
on ::marker
pseudo-elementstab-size
propertyMay 2021
Ship Sec-Fetch-*
headers (Fetch Metadata Request Headers)d
property on SVG <path>
elementsApril 2021
ascent-override
, descent-override
, and line-gap-override
font descriptorsforced-colors
media feature (née prefers-contrast
)March 2021
aspect-ratio
from width
/height
attributes for <video>
, <canvas>
and <input type=image>
ascent-override
, descent-override
, and line-gap-override
font descriptorsglyph-scale-factor
/size-adjust
descriptorAbortSignal.abort()
for creating an aborted AbortSignal
aspect-ratio
propertyfit-content()
functionFebruary 2021
border-radius
color-mix()
function:user-valid
and :user-invalid
pseudo-classesborder-radius
January 2021
December 2020
strict-origin-when-cross-origin
as default referrer policy:autofill
pseudo-class<menu type=context>
, <menuitem>
, and contextMenu
property (HTML context menus)signal
option for addEventListener
method (AbortSignal)November 2020
touch-action: pinch-zoom
value:focus-visible
pseudo-classOctober 2020
localhost
addresses as secure contexts (“potentially trustworthy”)conic-gradient()
notationSeptember 2020
math-style
propertybeforeinput
event and its getTargetRanges
method:is()
and :where()
pseudo-classesautocapitalize
attributeallow-downloads
keyword for the <iframe sandbox>
attribute::file-selector-button
pseudo-elementAugust 2020
selectionchange
event for <input>
and <textarea>
elementsJuly 2020
overflow: clip
value::-moz-focus-outer
pseudo-elementappearance
property (unprefixed)cross-fade()
functionprefers-contrast
media featureappearance
propertyJune 2020
<dialog>
elementinert
attributeenterkeyhint
attributeMay 2020
replaceChildren
method<link rel=preload>
aspect-ratio
property::file-chooser-button
pseudo-element:read-only
and :read-write
pseudo-classesApril 2020
:is()
and :where()
pseudo-classesMarch 2020
<script defer>
execution until all script-blocking stylesheets are loaded”getAnimations
method for the Element and Document interfacesFebruary 2020
suggestion
, mark
, and comment
roles and aria-description
attribute (ARIA annotations):focus-visible
pseudo-classmin()
, max()
, and clamp()
functionsconic-gradient()
notation<img loading>
attribute (for lazy-loading images)submit
event (contains submitter
property)<form>
requestSubmit
methodJanuary 2020
outline-style: auto
valueCross-Origin-Resource-Policy
headerbeforeinput
eventtext-underline-position
propertyDecember 2019
overscroll-behavior-inline
and overscroll-behavior-block
propertiesIDBTransaction
commit
methodtext-underline-position
propertyNovember 2019
allow
attributetranslate
, scale
, and rotate
properties (individual transforms)October 2019
column-span
propertyaspect-ratio
from image width
/height
attributesSeptember 2019
text-decoration-skip-ink
, text-decoration-thickness
, and text-underline-offset
propertiesformdata
event)X-Content-Type-Options: nosniff
for navigationsAugust 2019
clip-path: path()
valuesdisplay
propertyinline list-item
and inline flow-root list-item
values for the CSS display
propertyblock ruby
value for the CSS display
propertyfont-size: xxx-large
valuetext-decoration-skip-ink
propertyJuly 2019
text-decoration-width
propertyquotes: auto
valuebackdrop-filter
propertyJune 2019
aspect-ratio
from image width
/height
attributes@supports selector()
functionwebkitURL
constructor (legacy compatibility alias of URL
)white-space: break-spaces
valuetext-decoration-width
propertytext-underline-offset
propertyoverflow-block
and overflow-inline
propertiestext
, arrayBuffer
, and stream
methods on Blob
interfaceMay 2019
queueMicrotask
functionSameSite=Lax
by default, require Secure
for SameSite=None
)line-break
propertyApril 2019
noreferrer
feature for window.open
method<link rel="stylesheet" disabled>
attributepreventScroll
option for the focus
methodMarch 2019
::marker
pseudo-elementcounter-set
propertycontain
propertyimport()
syntax for dynamic importsrevert
keywordFebruary 2019
prefers-color-scheme
media feature-webkit-line-clamp
propertyInputEvent
data
and dataTransfer
propertiesJanuary 2019
rel="noopener"
for <a target="_blank">
elementsborder-block-color
, etc. properties and shorthandsborder-start-start-radius
, etc. propertiesinset
, inset-block
, and inset-inline
shorthandsmargin-block
and margin-inline
shorthandspadding-block
and padding-inline
shorthandsReport-To
header (part of Reporting API)December 2018
overflow-inline
and overflow-block
media featuresInputEvent
inputType
propertys
modifier for attribute selectorsbreak-before
, break-after
, and break-inside
propertiesNovember 2018
"keypress"
events when pressed key does not introduce text input"keydown"
and "keyup"
events during IME compositionrel="noopener"
for <a target="_blank">
elementsReportingObserver
)overflow-wrap: anywhere
valuedecode
methodenv()
notation (environment variables)October 2018
<script referrerpolicy>
attributeimport()
syntax for dynamic importsscreenLeft
and screenTop
properties (aliases for screenX
and screenY
)@supports
selector
functionSeptember 2018
scrollbar-color
and scrollbar-width
propertiesnavigator.getDisplayMedia
method (Screen Capture)August 2018
-webkit-
prefixed pseudo elements as valid CSS selectors”block
and inline
values for the CSS resize
property-webkit-appearance
propertyscrollbar-width
propertyHTMLMediaElement
allowedToPlay
propertyJuly 2018
<img decoding>
attributeprefers-reduced-motion
media feature (on Windows and macOS)Clear-Site-Data
headerscrollbar-face-color
and scrollbar-track-color
propertiesJune 2018
Element
toggleAttribute
methodpersist
and estimate
methods)Clear-Site-Data
headershape-outside
propertyMay 2018
import.meta
meta property in module scriptsAudioWorklet
interface (Web Audio API)Event
srcElement
property (alias of target
property)April 2018
application/javascript+binast
(JavaScript Binary AST content encoding)overflow
shorthand (accepts two values)SameSite
attribute for cookiesMarch 2018
February 2018
<script type="module">
)navigator.webdriver
(Boolean) propertypaint-order
property for HTML textJanuary 2018
overscroll-behavior
propertyDecember 2017
paint-order
property for HTML texttranslate
, scale
, and rotate
properties (individual transforms)November 2017
X-Frame-Options: SAMEORIGIN
(check all ancestor frames)EventTarget
constructorOctober 2017
overscroll-behavior
propertypreload
link relation (temporary)"navigation"
performance entry (replacement for navigation.timing
)workerStart
propertypointer
, hover
, any-pointer
, any-hover
)<a ping>
attributeSeptember 2017
August 2017
July 2017
preload
link relationMay 2017
SourceMap
response headerMarch 2017
line-height-step
property::cue
pseudo-elementframes()
timing functiontext-justify
propertytransform-box
propertyFebruary 2017
frames()
timing functionanimationcancel
eventorigin
property (self.origin
)text-justify
propertyclip-path
property (inset()
, circle()
, ellipse()
, polygon()
)January 2017
rgb(0 0 0 / 100%)
)Large-Allocation
header (non-standard)<script type="module">
)December 2016
vector-effect
property (additional values)caret-color
property<dialog>
elementdisplay: flow-root
valuesetBaseAndExtent
methodmask-image
property (repeated intent)November 2016
background-repeat-x
/background-repeat-y
and mask-repeat-x
/mask-repeat-y
propertiesrequestIdleCallback
functionOctober 2016
transitionrun
, transitionstart
, and transitioncancel
eventsshape-outside
propertyselectionstart
, selectionchange
)touch-action
property (only Level 1 values)September 2016
initial-letter
propertyisSecureContext
property in workersestimate
methodgetTransform
/setTransform
methodsAugust 2016
imageSmoothingEnabled
propertytransitionstart
eventminlength
attribute and tooShort
validity statedataset
API on SVG elementsJuly 2016
forEach
method on NodeList and DOMTokenListwebkitGetAsEntry
method) incl. file input webkitdirectory
attribute:any-link
pseudo-classdevicechange
eventgetConstraints
and getSettings
methodsonce
option for addEventListener
method__Secure-
/__Host-
cookie prefixestouch-action
propertytransform-style: preserve-3d
when opacity is applied”June 2016
WindowClient.navigate
methodmask-image
propertyMay 2016
text-align-last
propertyseekToNextFrame
method (non-standard)PerformanceObserver
APIspace
/round
values for CSS background-repeat
property:dir
pseudo-classallow-popups-to-escape-sandbox
keyword)allow-modals
keyword)passive
option)DOMTokenList.prototype.supports
propertyApril 2016
"noopener"
link relationgeolocation.watchPosition
to secure contexts”polygon
et al) for CSS clip-path
propertyrequestIdleCallback
functionElement.animate
methodprepend
, append
, before
, after
, replaceWith
methodsdocument.scrollingElement
property<details>
and <summary>
elements-webkit-text-stroke
propertyMarch 2016
-webkit-background-clip: text
text-combine-upright: all
navigator.hardwareConcurrency
color-adjust
propertyFebruary 2016
IDBKeyRange.includes()
fetch()
referrer and Referrer Policy APIJanuary 2016
document.elementsFromPoint
methodDecember 2015
-webkit-
prefixed CSS properties and featuresreferrerpolicy
attributeNovember 2015
<details>
and <summary>
elementsPerformance.translateTime
methodunicode-range
descriptortext-emphasis
property)October 2015
window.orientation
and 'orientationchange'
event::backdrop pseudo-element
for Fullscreen API