A weekly selection of the relevant Chromium and Firefox intents
271
565 commits
updated Jan 19, 2025
This is my selection of relevant Chromium and Firefox intents (from blink-dev and dev-platform@mozilla.org, respectively). Updated weekly.
Jump to section: Chromium | Firefox
January 2025
<dialog closedby> attribute:has-slotted pseudo-classnavigator.clipboard.contentsID methodhandwriting keyword for CSS touch-action propertyDecember 2024
FileSystemObserver APIexpect-no-linked-resources configuration pointshape() functiontext-box, text-box-trim and text-box-edge properties:open pseudo-classdynamic-range-limit propertyNovember 2024
attr() functionAnimation overallProgress propertyclipboardchange eventhint value for the HTML popover attributeNode moveBefore methodcontainertiming attribute)scroll-start-target propertyOctober 2024
aria-actions attributeclosedby attribute for HTML <dialog> element (light dismiss)::scroll-*-button pseudo-elements::column pseudo-element"interrupted" state for AudioContext (Web Audio API)sideways-rl and sideways-lr keywords for the CSS writing-mode propertybeforetoggle and toggle events for the <dialog> elementcaret-animation property::details-content pseudo-element and display property on <details>/<summary> elementsauto value for CSS view-transition-name propertySeptember 2024
:local-link pseudo-class:has-slotted pseudo-class<permission> element (Page-Embedded Permission Control) (cont.)@page margin boxesstretch sizing keywordcurrentcolor in relative color syntaxhighlightsFromPoint methodfont-variant-emoji propertyexpect-no-linked-resources configuration pointbox-decoration-break property (full support)fetchLater method (cont.)August 2024
appearance: none fallback style for <meter> elementsAccept-Language headerscheduler.yield methodpreferInitialWindowPlacement option for Picture-in-Picture APIJuly 2024
handwriting attributeFileSystemObserver APIinterpolate-size property and calc-size() function:visited links history (phase 2)getComposedRanges methodJune 2024
media-playback-while-not-rendered Permission PolicyplaceElement methodbox-decoration-break property (full support)aria-rowindextext and aria-colindextext attributescolor-interpolation: linearrgb on SVG gradientsruby-align propertydocument.caretPositionFromPoint methodsideways-rl and sideways-lr keywords for the CSS writing-mode propertyMay 2024
display: ruby)ruby-align propertyscrollsnapchange and scrollsnapchanging)"usb-unrestricted" Permission Policy)anchor-scope property<permission> element (Page-Embedded Permission Control)font-size-adjust property (new syntax)content property (multiple arguments including attr() and counter())<link rel="payment"> hints for pending push paymentstabbed display mode)April 2024
content property (multiple arguments including attr() and counter())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")URLPatternListcolor() 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 DeviceMotionEventsin(), 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-lineperformance.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 PointerEventOctober 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 headerTruncated — view the full README on GitHub.
A weekly selection of the relevant Chromium and Firefox intents
271
565 commits
updated Jan 19, 2025
This is my selection of relevant Chromium and Firefox intents (from blink-dev and dev-platform@mozilla.org, respectively). Updated weekly.
Jump to section: Chromium | Firefox
January 2025
<dialog closedby> attribute:has-slotted pseudo-classnavigator.clipboard.contentsID methodhandwriting keyword for CSS touch-action propertyDecember 2024
FileSystemObserver APIexpect-no-linked-resources configuration pointshape() functiontext-box, text-box-trim and text-box-edge properties:open pseudo-classdynamic-range-limit propertyNovember 2024
attr() functionAnimation overallProgress propertyclipboardchange eventhint value for the HTML popover attributeNode moveBefore methodcontainertiming attribute)scroll-start-target propertyOctober 2024
aria-actions attributeclosedby attribute for HTML <dialog> element (light dismiss)::scroll-*-button pseudo-elements::column pseudo-element"interrupted" state for AudioContext (Web Audio API)sideways-rl and sideways-lr keywords for the CSS writing-mode propertybeforetoggle and toggle events for the <dialog> elementcaret-animation property::details-content pseudo-element and display property on <details>/<summary> elementsauto value for CSS view-transition-name propertySeptember 2024
:local-link pseudo-class:has-slotted pseudo-class<permission> element (Page-Embedded Permission Control) (cont.)@page margin boxesstretch sizing keywordcurrentcolor in relative color syntaxhighlightsFromPoint methodfont-variant-emoji propertyexpect-no-linked-resources configuration pointbox-decoration-break property (full support)fetchLater method (cont.)August 2024
appearance: none fallback style for <meter> elementsAccept-Language headerscheduler.yield methodpreferInitialWindowPlacement option for Picture-in-Picture APIJuly 2024
handwriting attributeFileSystemObserver APIinterpolate-size property and calc-size() function:visited links history (phase 2)getComposedRanges methodJune 2024
media-playback-while-not-rendered Permission PolicyplaceElement methodbox-decoration-break property (full support)aria-rowindextext and aria-colindextext attributescolor-interpolation: linearrgb on SVG gradientsruby-align propertydocument.caretPositionFromPoint methodsideways-rl and sideways-lr keywords for the CSS writing-mode propertyMay 2024
display: ruby)ruby-align propertyscrollsnapchange and scrollsnapchanging)"usb-unrestricted" Permission Policy)anchor-scope property<permission> element (Page-Embedded Permission Control)font-size-adjust property (new syntax)content property (multiple arguments including attr() and counter())<link rel="payment"> hints for pending push paymentstabbed display mode)April 2024
content property (multiple arguments including attr() and counter())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")URLPatternListcolor() 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 DeviceMotionEventsin(), 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-lineperformance.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 PointerEventOctober 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 headerTruncated — view the full README on GitHub.