Web Baseline

1190 features shown

The alpha() CSS function computes a relative color value by adjusting the opacity of an origin color.

  • Chrome: full support since v151
  • Edge: full support since v151
  • Firefox: full support since v155
  • Safari: full support

alphaNewly available since Sep 2026CSScolor-types

Asynchronous iteration of a stream allows you to use for await … of loops to iterate through a stream's incoming data.

  • Chrome: full support since v124
  • Edge: full support since v124
  • Firefox: full support since v110
  • Safari: full support

async-iterable-streamsNewly available since Sep 2026Web APIstreams

The JavaScript promise integration (JSPI) suspends a WebAssembly module when it calls a JavaScript method that returns a promise. The module resumes when the promise is resolved. You can use this to call asynchronous Web APIs from synchronous WebAssembly.

  • Chrome: full support since v137
  • Edge: full support since v137
  • Firefox: full support since v153
  • Safari: full support

wasm-jspiNewly available since Sep 2026Otherwebassembly

The light-dark() CSS function accepts, in addition to colors, two <image> values, such as a gradient or URL, and uses one depending on the current color scheme.

  • Chrome: full support since v150
  • Edge: full support since v150
  • Firefox: full support since v150
  • Safari: full support

light-dark-imageNewly available since Sep 2026CSS

The overflow-anchor CSS property sets an element as a possible scroll anchor, reducing unintended scrolling when document changes occur above the current scrollport. This is enabled by default where supported.

  • Chrome: full support since v56
  • Edge: full support since v79
  • Firefox: full support since v66
  • Safari: full support

overflow-anchorNewly available since Sep 2026CSSscrolling

The await keyword, when used at the top level of a module (outside of an async function), delays parent module execution until after a promise fulfills.

  • Chrome: full support since v89
  • Edge: full support since v89
  • Firefox: full support since v89
  • Safari: full support

top-level-awaitNewly available since Sep 2026JavaScript

The autocorrect global HTML attribute controls whether to automatically correct spelling or punctuation errors for user input.

  • Chrome: full support since v153
  • Edge: full support
  • Firefox: full support since v136
  • Safari: full support since v14.1

autocorrectNewly available since Sep 2026HTML, Web API

The progress() CSS function returns a ratio for the relative position of one value between two other values, clamped between 0 and 1. You can use it to interpolate a value for other calculations.

  • Chrome: full support since v138
  • Edge: full support since v138
  • Firefox: full support since v155
  • Safari: full support since v26

progress-functionNewly available since Sep 2026CSS

The sibling-count() and sibling-index() CSS functions return integers that are useful to style elements based on their positions among siblings or on the number of siblings, for example as part of a calc() expression.

  • Chrome: full support since v138
  • Edge: full support since v138
  • Firefox: full support since v154
  • Safari: full support since v26.2

sibling-countNewly available since Aug 2026CSS

The getter methods of the Intl.Locale API provide supplemental information about a Unicode locale, such as the locale's calendar (for example, the first day in a week or the weekend start day), writing direction, 12- or 24-hour cycles, and numbering system.

  • Chrome: full support since v130
  • Edge: full support since v130
  • Firefox: full support since v153
  • Safari: full support since v17

intl-locale-infoNewly available since Jul 2026JavaScriptintl

The field-sizing CSS property allows form controls such as <textarea> to be sized based on their content.

  • Chrome: full support since v123
  • Edge: full support since v123
  • Firefox: full support since v152
  • Safari: full support since v26.2

field-sizingNewly available since Jun 2026CSS

Container style queries with the @container at-rule apply styles to an element based on the values of custom properties of its container.

  • Chrome: full support since v111
  • Edge: full support since v111
  • Firefox: full support since v151
  • Safari: full support since v18

container-style-queriesNewly available since May 2026CSScontainer-queries

The :open CSS pseudo-class matches elements that have open states, like <details>, <dialog>, or <select>, based on their state.

  • Chrome: full support since v133
  • Edge: full support since v133
  • Firefox: full support since v136
  • Safari: full support since v26.5

open-pseudoNewly available since May 2026CSSselectors

The source property of a ToggleEvent object is the element which triggered the toggle event to fire for a popover, <dialog>, or <details> element, if applicable.

  • Chrome: full support since v140
  • Edge: full support since v140
  • Firefox: full support since v145
  • Safari: full support since v26.5

toggleevent-sourceNewly available since May 2026Web API

The image-rendering: crisp-edges CSS declaration scales images to preserve lines without blurring.

  • Chrome: full support since v148
  • Edge: full support since v148
  • Firefox: full support since v65
  • Safari: full support since v7

crisp-edgesNewly available since May 2026CSSimage-scaling, images

The text-decoration-skip-ink: all CSS declaration forces interruptions in underlines and overlines where the line would cross a glyph. This contrasts with auto, which does not skip for CJK glyphs.

  • Chrome: full support since v148
  • Edge: full support since v148
  • Firefox: full support since v75
  • Safari: full support since v15.4

text-decoration-skip-ink-allNewly available since May 2026CSS

The SharedWorker() constructor accepts { type: "module" } to load scripts that use import and export. Also known as ECMAScript modules or ESM in shared workers.

  • Chrome: full support since v80
  • Edge: full support since v80
  • Firefox: full support since v114
  • Safari: full support since v16

js-modules-shared-workersNewly available since May 2026Web APIjs-modules, workers

The SharedWorker() constructor runs a script in its own thread, which can send and receive messages with other scripts running at the same origin.

  • Chrome: partial support since v5
    • SharedWorker.SharedWorker.mime_checks
  • Edge: partial support since v79
    • SharedWorker.SharedWorker.mime_checks
  • Firefox: full support since v29
  • Safari: partial support since v16
    • SharedWorker.SharedWorker.options_name_parameter

shared-workersNewly available since May 2026Web APIworkers

The contrast-color() CSS function picks a color that has guaranteed contrast against a specified foreground or background color.

  • Chrome: full support since v147
  • Edge: full support since v147
  • Firefox: full support since v146
  • Safari: full support since v26

contrast-colorNewly available since Apr 2026CSScolor-types

The Math.sumPrecise() static method returns the sum of an iterable of numbers. It avoids the precision loss of intermediate partial sums, as found using reduce() or a loop to add together an array of values.

  • Chrome: full support since v147
  • Edge: full support since v147
  • Firefox: full support since v137
  • Safari: full support since v26.2

math-sum-preciseNewly available since Apr 2026JavaScript

The @scope CSS at-rule sets the scope for a group of rules.

  • Chrome: full support since v143
  • Edge: full support since v143
  • Firefox: full support since v146
  • Safari: full support since v26.4

scopeNewly available since Mar 2026CSS, Web API

The baseline-shift CSS property sets the position of an element relative to its dominant baseline.

  • Chrome: full support since v1
  • Edge: full support since v79
  • Firefox: full support since v149
  • Safari: full support since v4

baseline-shiftNewly available since Mar 2026CSStext

CSP violation reporting sends a report to a URL nominated by the Reporting-Endpoints header or the ReportingObserver API when a page violates its content security policy.

  • Chrome: full support since v74
  • Edge: full support since v79
  • Firefox: full support since v149
  • Safari: full support since v18.4

reporting-csp-violationsNewly available since Mar 2026Web API, Otherreporting

Custom highlights style arbitrary text ranges, without adding extra elements to the DOM.

  • Chrome: full support since v105
  • Edge: full support since v105
  • Firefox: full support since v149
  • Safari: full support since v17.2

highlightNewly available since Mar 2026CSS, Web API

The Iterator.concat() JavaScript method returns an iterator that yields values from a sequence of iterators, exhausting each iterator before moving on to the next.

  • Chrome: full support since v146
  • Edge: full support since v146
  • Firefox: full support since v147
  • Safari: full support since v26.4

iterator-concatNewly available since Mar 2026JavaScriptiterators

The font-family: math CSS declaration uses the browser default font face for displaying mathematical expressions.

  • Chrome: full support since v109
  • Edge: full support since v109
  • Firefox: full support since v149
  • Safari: full support since v26.2

font-family-mathNewly available since Mar 2026CSSmathml

A ReadableStream constructed with { type: "bytes" } reads bytes from a stream without making extra copies, improving efficiency for streams of large chunks. Also known as BYOB or bring your own buffer.

  • Chrome: full support since v89
  • Edge: full support since v89
  • Firefox: full support since v102
  • Safari: partial support since v26.4
    • ReadableStreamBYOBReader.read.options_min_parameter
    • ReadableStreamBYOBReader.releaseLock.reject_pending_read_request

readable-byte-streamsNewly available since Mar 2026Web APIstreams

The Reporting-Endpoints HTTP header and ReportingObserver() API send selected reports, such as Content Security Policy (CSP) violation reports or crash reports, to a nominated URL or callback function.

  • Chrome: full support since v96
  • Edge: full support since v96
  • Firefox: full support since v149
  • Safari: partial support since v16.4
    • ReportingObserver.worker_support

reportingNewly available since Mar 2026Web API, Otherreporting

The WebTransport API transmits data between a client and a server, by using the HTTP/3 protocol.

  • Chrome: partial support since v97
    • WebTransport.WebTransport.options_allowPooling_parameter
    • WebTransport.WebTransport.options_congestionControl_parameter
    • WebTransport.WebTransport.options_requireUnreliable_parameter
    • WebTransport.congestionControl
    • WebTransport.createBidirectionalStream.options_sendOrder_parameter
    • WebTransport.createUnidirectionalStream.options_sendOrder_parameter
    • WebTransport.getStats
    • WebTransport.reliability
    • WebTransportBidirectionalStream.readable.returns_WebTransportReceiveStream
    • WebTransportBidirectionalStream.writable.returns_WebTransportSendStream
    • WebTransportReceiveStream
    • WebTransportReceiveStream.getStats
    • and 4 more
  • Edge: partial support since v97
    • WebTransport.WebTransport.options_allowPooling_parameter
    • WebTransport.WebTransport.options_congestionControl_parameter
    • WebTransport.WebTransport.options_requireUnreliable_parameter
    • WebTransport.congestionControl
    • WebTransport.createBidirectionalStream.options_sendOrder_parameter
    • WebTransport.createUnidirectionalStream.options_sendOrder_parameter
    • WebTransport.getStats
    • WebTransport.reliability
    • WebTransportBidirectionalStream.readable.returns_WebTransportReceiveStream
    • WebTransportBidirectionalStream.writable.returns_WebTransportSendStream
    • WebTransportReceiveStream
    • WebTransportReceiveStream.getStats
    • and 4 more
  • Firefox: partial support since v114
    • WebTransport.createUnidirectionalStream
    • WebTransport.getStats
    • WebTransportDatagramDuplexStream.byob_readers
  • Safari: full support since v26.4

webtransportNewly available since Mar 2026Web API

The text-indent: each-line CSS declaration indents text after forced breaks as well as to the first line of a block.

  • Chrome: full support since v146
  • Edge: full support since v146
  • Firefox: full support since v121
  • Safari: full support since v15

text-indent-each-lineNewly available since Mar 2026CSStext

The text-indent: hanging CSS declaration indents all lines except the first.

  • Chrome: full support since v146
  • Edge: full support since v146
  • Firefox: full support since v121
  • Safari: full support since v15

text-indent-hangingNewly available since Mar 2026CSStext

Branch hints in WebAssembly allows a browser to optimize performance when a branch is a likely to take a specific path.

  • Chrome: full support since v137
  • Edge: full support since v137
  • Firefox: full support since v148
  • Safari: full support since v16

wasm-branch-hintingNewly available since Feb 2026Otherwebassembly

The shape() CSS function creates shapes with a series of commands like line, move, and curve. It can be used with clip-path and shape-outside.

  • Chrome: full support since v135
  • Edge: full support since v135
  • Firefox: full support since v148
  • Safari: full support since v18.4

shape-functionNewly available since Feb 2026CSSclipping-shapes-masking

Trusted types allow you to lock down insecure parts of the DOM API and prevent client-side cross-site scripting (XSS) attacks.

  • Chrome: full support since v83
  • Edge: full support since v83
  • Firefox: full support since v148
  • Safari: full support since v26

trusted-typesNewly available since Feb 2026Web API, Othersecurity

The getOrInsert() and getOrInsertComputed() methods of Map objects get a value, setting and getting a default value if needed.

  • Chrome: full support since v145
  • Edge: full support since v145
  • Firefox: full support since v144
  • Safari: full support since v26.2

getorinsertNewly available since Feb 2026JavaScriptmaps, collections

Zstandard or zstd is a fast lossless compression algorithm. When used as a content encoding, it is often faster and offers better compression than brotli.

  • Chrome: full support since v123
  • Edge: full support since v123
  • Firefox: full support since v126
  • Safari: full support since v26.3

zstdNewly available since Feb 2026Other

The :active-view-transition CSS pseudo-class matches the root element when a view transition is active. The :active-view-transition-type() CSS pseudo-class matches only when the active view transition was started with the specified type.

  • Chrome: full support since v125
  • Edge: full support since v125
  • Firefox: full support since v147
  • Safari: full support since v18.2

active-view-transitionNewly available since Jan 2026CSS, Web APIview-transitions, selectors

The navigator.serviceWorker.register() method accepts { type: "module" } to load scripts that use import and export. Also known as ECMAScript modules or ESM in service workers.

  • Chrome: full support since v91
  • Edge: full support since v91
  • Firefox: full support since v147
  • Safari: full support since v15

js-modules-service-workersNewly available since Jan 2026JavaScript, Web APIjs-modules, workers

The navigation API initiates, intercepts, or modifies browser navigation actions. Not to be confused with the navigator API.

  • Chrome: full support since v102
  • Edge: full support since v102
  • Firefox: full support since v147
  • Safari: full support since v26.2

navigationNewly available since Jan 2026Web API

The rcap CSS length unit is a font-relative length equal to the value of the cap unit on the root element. Cap-height is approximately equal to the height of a capital Latin letter.

  • Chrome: full support since v118
  • Edge: full support since v118
  • Firefox: full support since v147
  • Safari: full support since v17.2

rcapNewly available since Jan 2026CSSunits