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<!doctype html><html lang="en">
<head>
<meta content="text/html; charset=utf-8" http-equiv="Content-Type">
<title>Compositing and Blending Level 2</title>
<meta content="width=device-width, initial-scale=1, shrink-to-fit=no" name="viewport">
<meta content="exploring" name="csswg-work-status">
<meta content="ED" name="w3c-status">
<meta content="Compositing describes how shapes of different elements are combined into a single image. There are various possible approaches for compositing. Previous versions of SVG and CSS used <a href="https://www.w3.org/TR/SVG11/masking.html#SimpleAlphaBlending">Simple Alpha Compositing</a>. In this model, each element is rendered into its own buffer and is then merged with its <a>backdrop</a> using the Porter Duff ''source-over'' operator. This specification will define a new compositing model that expands upon the Simple Alpha Compositing model by offering: <ul><li>additional Porter Duff compositing operators</li><li>advanced blending modes which allow control of how colors mix in the areas where shapes overlap</li><li>compositing groups</li></ul> In addition, this specification will define CSS properties for blending and group isolation and the properties of the {{globalCompositeOperation}} attribute." name="abstract">
<link href="../default.css" rel="stylesheet" type="text/css">
<link href="../csslogo.ico" rel="shortcut icon" type="image/x-icon">
<link href="https://www.w3.org/StyleSheets/TR/2021/W3C-ED" rel="stylesheet" type="text/css">
<meta content="Bikeshed version bbc364800, updated Mon Nov 15 13:57:55 2021 -0800" name="generator">
<link href="https://www.w3.org/TR/compositing-2/" rel="canonical">
<meta content="5e9fe6ebfa5a5ae8b1ec19d8578c7a6823ad6d01" name="document-revision">
<style type="text/css">
a[data-link-type=element]::before,span[data-link-type=element]::before {
content: '<';
}
a[data-link-type=element]::after,span[data-link-type=element]::after {
content: '>';
}
</style>
<style>/* style-autolinks */
.css.css, .property.property, .descriptor.descriptor {
color: var(--a-normal-text);
font-size: inherit;
font-family: inherit;
}
.css::before, .property::before, .descriptor::before {
content: "‘";
}
.css::after, .property::after, .descriptor::after {
content: "’";
}
.property, .descriptor {
/* Don't wrap property and descriptor names */
white-space: nowrap;
}
.type { /* CSS value <type> */
font-style: italic;
}
pre .property::before, pre .property::after {
content: "";
}
[data-link-type="property"]::before,
[data-link-type="propdesc"]::before,
[data-link-type="descriptor"]::before,
[data-link-type="value"]::before,
[data-link-type="function"]::before,
[data-link-type="at-rule"]::before,
[data-link-type="selector"]::before,
[data-link-type="maybe"]::before {
content: "‘";
}
[data-link-type="property"]::after,
[data-link-type="propdesc"]::after,
[data-link-type="descriptor"]::after,
[data-link-type="value"]::after,
[data-link-type="function"]::after,
[data-link-type="at-rule"]::after,
[data-link-type="selector"]::after,
[data-link-type="maybe"]::after {
content: "’";
}
[data-link-type].production::before,
[data-link-type].production::after,
.prod [data-link-type]::before,
.prod [data-link-type]::after {
content: "";
}
[data-link-type=element],
[data-link-type=element-attr] {
font-family: Menlo, Consolas, "DejaVu Sans Mono", monospace;
font-size: .9em;
}
[data-link-type=element]::before { content: "<" }
[data-link-type=element]::after { content: ">" }
[data-link-type=biblio] {
white-space: pre;
}</style>
<style>/* style-colors */
/* Any --*-text not paired with a --*-bg is assumed to have a transparent bg */
:root {
color-scheme: light dark;
--text: black;
--bg: white;
--unofficial-watermark: url(https://www.w3.org/StyleSheets/TR/2016/logos/UD-watermark);
--logo-bg: #1a5e9a;
--logo-active-bg: #c00;
--logo-text: white;
--tocnav-normal-text: #707070;
--tocnav-normal-bg: var(--bg);
--tocnav-hover-text: var(--tocnav-normal-text);
--tocnav-hover-bg: #f8f8f8;
--tocnav-active-text: #c00;
--tocnav-active-bg: var(--tocnav-normal-bg);
--tocsidebar-text: var(--text);
--tocsidebar-bg: #f7f8f9;
--tocsidebar-shadow: rgba(0,0,0,.1);
--tocsidebar-heading-text: hsla(203,20%,40%,.7);
--toclink-text: var(--text);
--toclink-underline: #3980b5;
--toclink-visited-text: var(--toclink-text);
--toclink-visited-underline: #054572;
--heading-text: #005a9c;
--hr-text: var(--text);
--algo-border: #def;
--del-text: red;
--del-bg: transparent;
--ins-text: #080;
--ins-bg: transparent;
--a-normal-text: #034575;
--a-normal-underline: #bbb;
--a-visited-text: var(--a-normal-text);
--a-visited-underline: #707070;
--a-hover-bg: rgba(75%, 75%, 75%, .25);
--a-active-text: #c00;
--a-active-underline: #c00;
--blockquote-border: silver;
--blockquote-bg: transparent;
--blockquote-text: currentcolor;
--issue-border: #e05252;
--issue-bg: #fbe9e9;
--issue-text: var(--text);
--issueheading-text: #831616;
--example-border: #e0cb52;
--example-bg: #fcfaee;
--example-text: var(--text);
--exampleheading-text: #574b0f;
--note-border: #52e052;
--note-bg: #e9fbe9;
--note-text: var(--text);
--noteheading-text: hsl(120, 70%, 30%);
--notesummary-underline: silver;
--assertion-border: #aaa;
--assertion-bg: #eee;
--assertion-text: black;
--advisement-border: orange;
--advisement-bg: #fec;
--advisement-text: var(--text);
--advisementheading-text: #b35f00;
--warning-border: red;
--warning-bg: hsla(40,100%,50%,0.95);
--warning-text: var(--text);
--amendment-border: #330099;
--amendment-bg: #F5F0FF;
--amendment-text: var(--text);
--amendmentheading-text: #220066;
--def-border: #8ccbf2;
--def-bg: #def;
--def-text: var(--text);
--defrow-border: #bbd7e9;
--datacell-border: silver;
--indexinfo-text: #707070;
--indextable-hover-text: black;
--indextable-hover-bg: #f7f8f9;
--outdatedspec-bg: rgba(0, 0, 0, .5);
--outdatedspec-text: black;
--outdated-bg: maroon;
--outdated-text: white;
--outdated-shadow: red;
--editedrec-bg: darkorange;
}</style>
<style>/* style-counters */
body {
counter-reset: example figure issue;
}
.issue {
counter-increment: issue;
}
.issue:not(.no-marker)::before {
content: "Issue " counter(issue);
}
.example {
counter-increment: example;
}
.example:not(.no-marker)::before {
content: "Example " counter(example);
}
.invalid.example:not(.no-marker)::before,
.illegal.example:not(.no-marker)::before {
content: "Invalid Example" counter(example);
}
figcaption {
counter-increment: figure;
}
figcaption:not(.no-marker)::before {
content: "Figure " counter(figure) " ";
}</style>
<style>/* style-dfn-panel */
:root {
--dfnpanel-bg: #ddd;
--dfnpanel-text: var(--text);
}
.dfn-panel {
position: absolute;
z-index: 35;
height: auto;
width: -webkit-fit-content;
width: fit-content;
max-width: 300px;
max-height: 500px;
overflow: auto;
padding: 0.5em 0.75em;
font: small Helvetica Neue, sans-serif, Droid Sans Fallback;
background: var(--dfnpanel-bg);
color: var(--dfnpanel-text);
border: outset 0.2em;
}
.dfn-panel:not(.on) { display: none; }
.dfn-panel * { margin: 0; padding: 0; text-indent: 0; }
.dfn-panel > b { display: block; }
.dfn-panel a { color: var(--dfnpanel-text); }
.dfn-panel a:not(:hover) { text-decoration: none !important; border-bottom: none !important; }
.dfn-panel > b + b { margin-top: 0.25em; }
.dfn-panel ul { padding: 0; }
.dfn-panel li { list-style: inside; }
.dfn-panel.activated {
display: inline-block;
position: fixed;
left: .5em;
bottom: 2em;
margin: 0 auto;
max-width: calc(100vw - 1.5em - .4em - .5em);
max-height: 30vh;
}
.dfn-paneled { cursor: pointer; }
</style>
<style>/* style-issues */
a[href].issue-return {
float: right;
float: inline-end;
color: var(--issueheading-text);
font-weight: bold;
text-decoration: none;
}
</style>
<style>/* style-md-lists */
/* This is a weird hack for me not yet following the commonmark spec
regarding paragraph and lists. */
[data-md] > :first-child {
margin-top: 0;
}
[data-md] > :last-child {
margin-bottom: 0;
}</style>
<style>/* style-mdn-anno */
@media (max-width: 767px) { .mdn-anno { opacity: .1 } }
.mdn-anno { font: 1em sans-serif; padding: 0.3em; position: absolute; z-index: 8; right: 0.3em; background: #EEE; color: black; box-shadow: 0 0 3px #999; overflow: hidden; border-collapse: initial; border-spacing: initial; min-width: 9em; max-width: min-content; white-space: nowrap; word-wrap: normal; hyphens: none}
.mdn-anno:not(.wrapped) { opacity: 1}
.mdn-anno:hover { z-index: 9 }
.mdn-anno.wrapped { min-width: 0 }
.mdn-anno.wrapped > :not(button) { display: none; }
.mdn-anno > .mdn-anno-btn { cursor: pointer; border: none; color: #000; background: transparent; margin: -8px; float: right; padding: 10px 8px 8px 8px; outline: none; }
.mdn-anno > .mdn-anno-btn > .less-than-two-engines-flag { color: red; padding-right: 2px; }
.mdn-anno > .mdn-anno-btn > .all-engines-flag { color: green; padding-right: 2px; }
.mdn-anno > .mdn-anno-btn > span { color: #fff; background-color: #000; font-weight: normal; font-family: zillaslab, Palatino, "Palatino Linotype", serif; padding: 2px 3px 0px 3px; line-height: 1.3em; vertical-align: top; }
.mdn-anno > .feature { margin-top: 20px; }
.mdn-anno > .feature:not(:first-of-type) { border-top: 1px solid #999; margin-top: 6px; padding-top: 2px; }
.mdn-anno > .feature > .less-than-two-engines-text { color: red }
.mdn-anno > .feature > .all-engines-text { color: green }
.mdn-anno > .feature > p { font-size: .75em; margin-top: 6px; margin-bottom: 0; }
.mdn-anno > .feature > p + p { margin-top: 3px; }
.mdn-anno > .feature > .support { display: block; font-size: 0.6em; margin: 0; padding: 0; margin-top: 2px }
.mdn-anno > .feature > .support + div { padding-top: 0.5em; }
.mdn-anno > .feature > .support > hr { display: block; border: none; border-top: 1px dotted #999; padding: 3px 0px 0px 0px; margin: 2px 3px 0px 3px; }
.mdn-anno > .feature > .support > hr::before { content: ""; }
.mdn-anno > .feature > .support > span { padding: 0.2em 0; display: block; display: table; }
.mdn-anno > .feature > .support > span.no { color: #CCCCCC; filter: grayscale(100%); }
.mdn-anno > .feature > .support > span.no::before { opacity: 0.5; }
.mdn-anno > .feature > .support > span:first-of-type { padding-top: 0.5em; }
.mdn-anno > .feature > .support > span > span { padding: 0 0.5em; display: table-cell; }
.mdn-anno > .feature > .support > span > span:first-child { width: 100%; }
.mdn-anno > .feature > .support > span > span:last-child { width: 100%; white-space: pre; padding: 0; }
.mdn-anno > .feature > .support > span::before { content: ' '; display: table-cell; min-width: 1.5em; height: 1.5em; background: no-repeat center center; background-size: contain; text-align: right; font-size: 0.75em; font-weight: bold; }
.mdn-anno > .feature > .support > .chrome_android::before { background-image: url(https://resources.whatwg.org/browser-logos/chrome.svg); }
.mdn-anno > .feature > .support > .firefox_android::before { background-image: url(https://resources.whatwg.org/browser-logos/firefox.png); }
.mdn-anno > .feature > .support > .chrome::before { background-image: url(https://resources.whatwg.org/browser-logos/chrome.svg); }
.mdn-anno > .feature > .support > .edge_blink::before { background-image: url(https://resources.whatwg.org/browser-logos/edge.svg); }
.mdn-anno > .feature > .support > .edge::before { background-image: url(https://resources.whatwg.org/browser-logos/edge_legacy.svg); }
.mdn-anno > .feature > .support > .firefox::before { background-image: url(https://resources.whatwg.org/browser-logos/firefox.png); }
.mdn-anno > .feature > .support > .ie::before { background-image: url(https://resources.whatwg.org/browser-logos/ie.png); }
.mdn-anno > .feature > .support > .safari_ios::before { background-image: url(https://resources.whatwg.org/browser-logos/safari-ios.svg); }
.mdn-anno > .feature > .support > .nodejs::before { background-image: url(https://nodejs.org/static/images/favicons/favicon.ico); }
.mdn-anno > .feature > .support > .opera_android::before { background-image: url(https://resources.whatwg.org/browser-logos/opera.svg); }
.mdn-anno > .feature > .support > .opera::before { background-image: url(https://resources.whatwg.org/browser-logos/opera.svg); }
.mdn-anno > .feature > .support > .safari::before { background-image: url(https://resources.whatwg.org/browser-logos/safari.png); }
.mdn-anno > .feature > .support > .samsunginternet_android::before { background-image: url(https://resources.whatwg.org/browser-logos/samsung.svg); }
.mdn-anno > .feature > .support > .webview_android::before { background-image: url(https://resources.whatwg.org/browser-logos/android-webview.png); }
.name-slug-mismatch { color: red }
.caniuse-status:hover { z-index: 9; }
/* dt, li, .issue, .note, and .example are "position: relative", so to put annotation at right margin, must move to right of containing block */
.h-entry:not(.status-LS) dt > .mdn-anno, .h-entry:not(.status-LS) li > .mdn-anno, .h-entry:not(.status-LS) .issue > .mdn-anno, .h-entry:not(.status-LS) .note > .mdn-anno, .h-entry:not(.status-LS) .example > .mdn-anno { right: -6.7em; }
.h-entry p + .mdn-anno { margin-top: 0; }
h2 + .mdn-anno.after { margin: -48px 0 0 0; }
h3 + .mdn-anno.after { margin: -46px 0 0 0; }
h4 + .mdn-anno.after { margin: -42px 0 0 0; }
h5 + .mdn-anno.after { margin: -40px 0 0 0; }
h6 + .mdn-anno.after { margin: -40px 0 0 0; }
</style>
<style>/* style-selflinks */
:root {
--selflink-text: white;
--selflink-bg: gray;
--selflink-hover-text: black;
}
.heading, .issue, .note, .example, li, dt {
position: relative;
}
a.self-link {
position: absolute;
top: 0;
left: calc(-1 * (3.5rem - 26px));
width: calc(3.5rem - 26px);
height: 2em;
text-align: center;
border: none;
transition: opacity .2s;
opacity: .5;
}
a.self-link:hover {
opacity: 1;
}
.heading > a.self-link {
font-size: 83%;
}
li > a.self-link {
left: calc(-1 * (3.5rem - 26px) - 2em);
}
dfn > a.self-link {
top: auto;
left: auto;
opacity: 0;
width: 1.5em;
height: 1.5em;
background: var(--selflink-bg);
color: var(--selflink-text);
font-style: normal;
transition: opacity .2s, background-color .2s, color .2s;
}
dfn:hover > a.self-link {
opacity: 1;
}
dfn > a.self-link:hover {
color: var(--selflink-hover-text);
}
a.self-link::before { content: "¶"; }
.heading > a.self-link::before { content: "§"; }
dfn > a.self-link::before { content: "#"; }
</style>
<style>/* style-darkmode */
@media (prefers-color-scheme: dark) {
:root {
--text: #ddd;
--bg: black;
--unofficial-watermark: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='400' height='400'%3E%3Cg fill='%23100808' transform='translate(200 200) rotate(-45) translate(-200 -200)' stroke='%23100808' stroke-width='3'%3E%3Ctext x='50%25' y='220' style='font: bold 70px sans-serif; text-anchor: middle; letter-spacing: 6px;'%3EUNOFFICIAL%3C/text%3E%3Ctext x='50%25' y='305' style='font: bold 70px sans-serif; text-anchor: middle; letter-spacing: 6px;'%3EDRAFT%3C/text%3E%3C/g%3E%3C/svg%3E");
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--a-active-underline: var(--a-active-text);
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--blockquote-bg: var(--borderedblock-bg);
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--issue-border: #e05252;
--issue-bg: var(--borderedblock-bg);
--issue-text: var(--text);
--issueheading-text: hsl(0deg, 70%, 70%);
--example-border: hsl(50deg, 90%, 60%);
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--outdatedspec-text: black;
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--outdated-text: white;
--outdated-shadow: red;
--editedrec-bg: darkorange;
}
/* In case a transparent-bg image doesn't expect to be on a dark bg,
which is quite common in practice... */
img { background: white; }
}
@media (prefers-color-scheme: dark) {
:root {
--selflink-text: black;
--selflink-bg: silver;
--selflink-hover-text: white;
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}
@media (prefers-color-scheme: dark) {
:root {
--dfnpanel-bg: #222;
--dfnpanel-text: var(--text);
}
}</style>
<body class="h-entry">
<div class="head">
<p data-fill-with="logo"><a class="logo" href="https://www.w3.org/"> <img alt="W3C" height="48" src="https://www.w3.org/StyleSheets/TR/2021/logos/W3C" width="72"> </a> </p>
<h1 class="p-name no-ref" id="title">Compositing and Blending Level 2</h1>
<p id="w3c-state"><a href="https://www.w3.org/standards/types#ED">Editor’s Draft</a>, <time class="dt-updated" datetime="2022-01-06">6 January 2022</time></p>
<details open>
<summary>More details about this document</summary>
<div data-fill-with="spec-metadata">
<dl>
<dt>This version:
<dd><a class="u-url" href="https://drafts.fxtf.org/compositing-2/">https://drafts.fxtf.org/compositing-2/</a>
<dt>Latest published version:
<dd><a href="https://www.w3.org/TR/compositing-2/">https://www.w3.org/TR/compositing-2/</a>
<dt>Previous Versions:
<dd><a href rel="prev"></a>
<dt class="editor">Editors:
<dd class="editor p-author h-card vcard" data-editor-id="106988"><a class="p-name fn u-email email" href="mailto:cabanier@adobe.com">Rik Cabanier</a> (<span class="p-org org">Adobe Systems Inc.</span>)
<dd class="editor p-author h-card vcard" data-editor-id="90243"><a class="p-name fn u-email email" href="mailto:chrishtr@chromium.org">Chris Harrelson</a> (<span class="p-org org">Google Inc.</span>)
<dt class="editor">Former Editor:
<dd class="editor p-author h-card vcard"><a class="p-name fn u-email email" href="mailto:Nikos.Andronikos@cisra.canon.com.au">Nikos Andronikos</a> (<span class="p-org org">Canon Information Systems Research Australia</span>)
<dt>Issue Tracking:
<dd><a href="https://github.com/w3c/fxtf-drafts/labels/compositing-2">GitHub Issues</a>
<dt>Suggest an Edit for this Spec:
<dd><a href="https://github.com/w3c/fxtf-drafts/blob/main/compositing-2/Overview.bs">GitHub Editor</a>
</dl>
</div>
</details>
<div data-fill-with="warning"></div>
<p class="copyright" data-fill-with="copyright"><a href="https://www.w3.org/Consortium/Legal/ipr-notice#Copyright">Copyright</a> © 2022 <a href="https://www.w3.org/"><abbr title="World Wide Web Consortium">W3C</abbr></a><sup>®</sup> (<a href="https://www.csail.mit.edu/"><abbr title="Massachusetts Institute of Technology">MIT</abbr></a>, <a href="https://www.ercim.eu/"><abbr title="European Research Consortium for Informatics and Mathematics">ERCIM</abbr></a>, <a href="https://www.keio.ac.jp/">Keio</a>, <a href="https://ev.buaa.edu.cn/">Beihang</a>). W3C <a href="https://www.w3.org/Consortium/Legal/ipr-notice#Legal_Disclaimer">liability</a>, <a href="https://www.w3.org/Consortium/Legal/ipr-notice#W3C_Trademarks">trademark</a> and <a href="https://www.w3.org/Consortium/Legal/2015/copyright-software-and-document">permissive document license</a> rules apply. </p>
<hr title="Separator for header">
</div>
<div class="p-summary" data-fill-with="abstract">
<h2 class="no-num no-toc no-ref heading settled" id="abstract"><span class="content">Abstract</span></h2>
<p>Compositing describes how shapes of different elements are combined into a single image. There are various possible approaches for compositing. Previous versions of SVG and CSS used <a href="https://www.w3.org/TR/SVG11/masking.html#SimpleAlphaBlending">Simple Alpha Compositing</a>. In this model, each element is rendered into its own buffer and is then merged with its <a data-link-type="dfn" href="#backdrop" id="ref-for-backdrop">backdrop</a> using the Porter Duff <span class="css">source-over</span> operator. This specification will define a new compositing model that expands upon the Simple Alpha Compositing model by offering:</p>
<ul>
<li>additional Porter Duff compositing operators
<li>advanced blending modes which allow control of how colors mix in the areas where shapes overlap
<li>compositing groups
</ul>
In addition, this specification will define CSS properties for blending and group isolation and the properties of the <code class="idl"><a data-link-type="idl" href="https://html.spec.whatwg.org/multipage/canvas.html#dom-context-2d-globalcompositeoperation" id="ref-for-dom-context-2d-globalcompositeoperation">globalCompositeOperation</a></code> attribute.
</div>
<h2 class="no-num no-toc no-ref heading settled" id="status"><span class="content">Status of this document</span></h2>
<div data-fill-with="status">
<p> This is a public copy of the editors’ draft.
It is provided for discussion only and may change at any moment.
Its publication here does not imply endorsement of its contents by W3C.
Don’t cite this document other than as work in progress. </p>
<p> <a href="https://github.com/w3c/fxtf-drafts/issues">GitHub Issues</a> are preferred for discussion of this specification.
When filing an issue, please put the text “compositing” in the title,
preferably like this:
“[compositing] <i data-lt>…summary of comment…</i>”.
All issues and comments are <a href="https://lists.w3.org/Archives/Public/public-fxtf-archive/">archived</a>,
and there is also a <a href="http://lists.w3.org/Archives/Public/public-fx/">historical archive</a>. </p>
<p> This document was produced by the <a href="https://www.w3.org/groups/wg/css">CSS Working Group</a> (part of the <a href="https://www.w3.org/Style/">Style Activity</a>). </p>
<p> This document was produced by a group operating under
the <a href="https://www.w3.org/Consortium/Patent-Policy-20200915/">W3C Patent Policy</a>.
W3C maintains a <a href="https://www.w3.org/2004/01/pp-impl/32061/status" rel="disclosure">public list of any patent disclosures</a> made in connection with the deliverables of the group;
that page also includes instructions for disclosing a patent.
An individual who has actual knowledge of a patent which the individual believes contains <a href="https://www.w3.org/Consortium/Patent-Policy-20200915/#def-essential">Essential Claim(s)</a> must disclose the information in accordance with <a href="https://www.w3.org/Consortium/Patent-Policy-20200915/#sec-Disclosure">section 6 of the W3C Patent Policy</a>. </p>
<p> This document is governed by the <a href="https://www.w3.org/2021/Process-20211102/" id="w3c_process_revision">2 November 2021 W3C Process Document</a>. </p>
<p></p>
</div>
<div data-fill-with="at-risk"></div>
<nav data-fill-with="table-of-contents" id="toc">
<h2 class="no-num no-toc no-ref" id="contents">Table of Contents</h2>
<ol class="toc" role="directory">
<li><a href="#introduction"><span class="secno">1</span> <span class="content">Introduction</span></a>
<li>
<a href="#reading-this-document"><span class="secno">2</span> <span class="content">Reading This Document</span></a>
<ol class="toc">
<li><a href="#module-interactions"><span class="secno">2.1</span> <span class="content">Module interactions</span></a>
<li><a href="#values"><span class="secno">2.2</span> <span class="content">Values</span></a>
</ol>
<li>
<a href="#csscompositingandblending"><span class="secno">3</span> <span class="content">Specifying Blending in CSS </span></a>
<ol class="toc">
<li><a href="#compositingandblendingorder"><span class="secno">3.1</span> <span class="content">Order of graphical operations</span></a>
<li><a href="#csscompositingrules_CSS"><span class="secno">3.2</span> <span class="content">Behavior specific to HTML</span></a>
<li><a href="#csscompositingrules_SVG"><span class="secno">3.3</span> <span class="content">Behavior specific to SVG</span></a>
<li>
<a href="#csskeywords"><span class="secno">3.4</span> <span class="content">CSS Properties</span></a>
<ol class="toc">
<li><a href="#mix-blend-mode"><span class="secno">3.4.1</span> <span class="content">The <span class="property">mix-blend-mode</span> property</span></a>
<li><a href="#isolation"><span class="secno">3.4.2</span> <span class="content">The <span class="property">isolation</span> property</span></a>
<li><a href="#background-blend-mode"><span class="secno">3.4.3</span> <span class="content">The <span class="property">background-blend-mode</span> property</span></a>
</ol>
</ol>
<li><a href="#canvascompositingandblending"><span class="secno">4</span> <span class="content">Specifying Compositing and Blending in Canvas 2D</span></a>
<li>
<a href="#whatiscompositing"><span class="secno">5</span> <span class="content">Introduction to compositing</span></a>
<ol class="toc">
<li>
<a href="#simplealphacompositing"><span class="secno">5.1</span> <span class="content">Simple alpha compositing</span></a>
<ol class="toc">
<li><a href="#simplealphacompositingexamples"><span class="secno">5.1.1</span> <span class="content">Examples of simple alpha compositing</span></a>
</ol>
</ol>
<li><a href="#generalformula"><span class="secno">6</span> <span class="content">General Formula for Compositing and Blending</span></a>
<li>
<a href="#backdropCalc"><span class="secno">7</span> <span class="content">Backdrop calculation</span></a>
<ol class="toc">
<li><a href="#backdropexamples"><span class="secno">7.1</span> <span class="content">Examples of backdrop calculation</span></a>
</ol>
<li>
<a href="#groups"><span class="secno">8</span> <span class="content">Compositing Groups</span></a>
<ol class="toc">
<li><a href="#groupinvariance"><span class="secno">8.1</span> <span class="content">Group invariance</span></a>
<li><a href="#isolatedgroups"><span class="secno">8.2</span> <span class="content">Isolated Groups</span></a>
<li><a href="#pagebackdrop"><span class="secno">8.3</span> <span class="content">The Root Element Group</span></a>
<li><a href="#rootgroup"><span class="secno">8.4</span> <span class="content">The Root Group</span></a>
</ol>
<li>
<a href="#advancedcompositing"><span class="secno">9</span> <span class="content">Advanced compositing features</span></a>
<ol class="toc">
<li>
<a href="#porterduffcompositingoperators"><span class="secno">9.1</span> <span class="content">The Porter Duff Compositing Operators</span></a>
<ol class="toc">
<li><a href="#porterduffcompositingoperators_clear"><span class="secno">9.1.1</span> <span class="content">Clear</span></a>
<li><a href="#porterduffcompositingoperators_src"><span class="secno">9.1.2</span> <span class="content">Copy</span></a>
<li><a href="#porterduffcompositingoperators_dst"><span class="secno">9.1.3</span> <span class="content">Destination</span></a>
<li><a href="#porterduffcompositingoperators_srcover"><span class="secno">9.1.4</span> <span class="content">Source Over</span></a>
<li><a href="#porterduffcompositingoperators_dstover"><span class="secno">9.1.5</span> <span class="content">Destination Over</span></a>
<li><a href="#porterduffcompositingoperators_srcin"><span class="secno">9.1.6</span> <span class="content">Source In</span></a>
<li><a href="#porterduffcompositingoperators_dstin"><span class="secno">9.1.7</span> <span class="content">Destination In</span></a>
<li><a href="#porterduffcompositingoperators_srcout"><span class="secno">9.1.8</span> <span class="content">Source Out</span></a>
<li><a href="#porterduffcompositingoperators_dstout"><span class="secno">9.1.9</span> <span class="content">Destination Out</span></a>
<li><a href="#porterduffcompositingoperators_srcatop"><span class="secno">9.1.10</span> <span class="content">Source Atop</span></a>
<li><a href="#porterduffcompositingoperators_dstatop"><span class="secno">9.1.11</span> <span class="content">Destination Atop</span></a>
<li><a href="#porterduffcompositingoperators_xor"><span class="secno">9.1.12</span> <span class="content">XOR</span></a>
<li><a href="#porterduffcompositingoperators_plus"><span class="secno">9.1.13</span> <span class="content">Lighter</span></a>
<li><a href="#porterduffcompositingoperators_plus_darker"><span class="secno">9.1.14</span> <span class="content">Plus-darker</span></a>
<li><a href="#porterduffcompositingoperators_plus_lighter"><span class="secno">9.1.15</span> <span class="content">Plus-lighter</span></a>
</ol>
<li><a href="#groupcompositing"><span class="secno">9.2</span> <span class="content">Group compositing behavior with Porter Duff modes</span></a>
</ol>
<li>
<a href="#blending"><span class="secno">10</span> <span class="content">Blending</span></a>
<ol class="toc">
<li>
<a href="#blendingseparable"><span class="secno">10.1</span> <span class="content">Separable blend modes</span></a>
<ol class="toc">
<li><a href="#blendingnormal"><span class="secno">10.1.1</span> <span class="content"><span>normal</span> blend mode</span></a>
<li><a href="#blendingmultiply"><span class="secno">10.1.2</span> <span class="content"><span>multiply</span> blend mode</span></a>
<li><a href="#blendingscreen"><span class="secno">10.1.3</span> <span class="content"><span>screen</span> blend mode</span></a>
<li><a href="#blendingoverlay"><span class="secno">10.1.4</span> <span class="content"><span>overlay</span> blend mode</span></a>
<li><a href="#blendingdarken"><span class="secno">10.1.5</span> <span class="content"><span>darken</span> blend mode</span></a>
<li><a href="#blendinglighten"><span class="secno">10.1.6</span> <span class="content"><span>lighten</span> blend mode</span></a>
<li><a href="#blendingcolordodge"><span class="secno">10.1.7</span> <span class="content"><span>color-dodge</span> blend mode</span></a>
<li><a href="#blendingcolorburn"><span class="secno">10.1.8</span> <span class="content"><span>color-burn</span> blend mode</span></a>
<li><a href="#blendinghardlight"><span class="secno">10.1.9</span> <span class="content"><span>hard-light</span> blend mode</span></a>
<li><a href="#blendingsoftlight"><span class="secno">10.1.10</span> <span class="content"><span>soft-light</span> blend mode</span></a>
<li><a href="#blendingdifference"><span class="secno">10.1.11</span> <span class="content"><span>difference</span> blend mode</span></a>
<li><a href="#blendingexclusion"><span class="secno">10.1.12</span> <span class="content"><span>exclusion</span> blend mode</span></a>
</ol>
<li>
<a href="#blendingnonseparable"><span class="secno">10.2</span> <span class="content">Non-separable blend modes</span></a>
<ol class="toc">
<li><a href="#blendinghue"><span class="secno">10.2.1</span> <span class="content"><span>hue</span> blend mode</span></a>
<li><a href="#blendingsaturation"><span class="secno">10.2.2</span> <span class="content"><span>saturation</span> blend mode</span></a>
<li><a href="#blendingcolor"><span class="secno">10.2.3</span> <span class="content"><span>color</span> blend mode</span></a>
<li><a href="#blendingluminosity"><span class="secno">10.2.4</span> <span class="content"><span>luminosity</span> blend mode</span></a>
</ol>
<li><a href="#isolationblending"><span class="secno">10.3</span> <span class="content">Effect of group isolation on blending</span></a>
</ol>
<li><a href="#security"><span class="secno">11</span> <span class="content">Security issues with compositing and blending</span></a>
<li><a href="#changes"><span class="secno">12</span> <span class="content">Changes</span></a>
<li>
<a href="#w3c-conformance"><span class="secno"></span> <span class="content"> Conformance</span></a>
<ol class="toc">
<li><a href="#w3c-conventions"><span class="secno"></span> <span class="content"> Document conventions</span></a>
<li><a href="#w3c-conformance-classes"><span class="secno"></span> <span class="content"> Conformance classes</span></a>
<li>
<a href="#w3c-partial"><span class="secno"></span> <span class="content"> Partial implementations</span></a>
<ol class="toc">
<li><a href="#w3c-conform-future-proofing"><span class="secno"></span> <span class="content"> Implementations of Unstable and Proprietary Features</span></a>
</ol>
<li><a href="#w3c-testing"><span class="secno"></span> <span class="content"> Non-experimental implementations</span></a>
</ol>
<li>
<a href="#index"><span class="secno"></span> <span class="content">Index</span></a>
<ol class="toc">
<li><a href="#index-defined-here"><span class="secno"></span> <span class="content">Terms defined by this specification</span></a>
<li><a href="#index-defined-elsewhere"><span class="secno"></span> <span class="content">Terms defined by reference</span></a>
</ol>
<li>
<a href="#references"><span class="secno"></span> <span class="content">References</span></a>
<ol class="toc">
<li><a href="#normative"><span class="secno"></span> <span class="content">Normative References</span></a>
<li><a href="#informative"><span class="secno"></span> <span class="content">Informative References</span></a>
</ol>
<li><a href="#property-index"><span class="secno"></span> <span class="content">Property Index</span></a>
</ol>
</nav>
<main>
<h2 class="heading settled" data-level="1" id="introduction"><span class="secno">1. </span><span class="content">Introduction</span><a class="self-link" href="#introduction"></a></h2>
<p><em>This subsection is non-normative.</em><br> The first part of this document describes the properties used to control the compositing in CSS.
The second part will describe the algorithms of Porter Duff compositing and blending. </p>
<h2 class="heading settled" data-level="2" id="reading-this-document"><span class="secno">2. </span><span class="content">Reading This Document</span><a class="self-link" href="#reading-this-document"></a></h2>
<p>Each section of this document is normative unless otherwise specified.</p>
<h3 class="heading settled" data-level="2.1" id="module-interactions"><span class="secno">2.1. </span><span class="content">Module interactions</span><a class="self-link" href="#module-interactions"></a></h3>
<p>This specification defines a set of CSS properties that affect the visual rendering of elements to which
those properties are applied; these effects are applied after elements have been sized and positioned according
to the <span spec-section="#visual-model-intro">Visual formatting model</span>. Some values of these properties result in the creation of a <a data-link-type="dfn">containing block</a>,
and/or the creation of a <a data-link-type="dfn" href="https://drafts.csswg.org/css2/#stacking-context" id="ref-for-stacking-context">stacking context</a>.</p>
<p>The <a class="property" data-link-type="propdesc" href="#propdef-background-blend-mode" id="ref-for-propdef-background-blend-mode">background-blend-mode</a> property also builds upon the properties defined in the <a href="https://www.w3.org/TR/css3-background/#placement" title="Backgrounds and Borders">CSS Backgrounds and Borders</a> module <a data-link-type="biblio" href="#biblio-css3bg">[CSS3BG]</a>.</p>
<p>This specification also enhances the rules as specified in <a href="https://www.w3.org/TR/2003/REC-SVG11-20030114/masking.html#SimpleAlphaBlending" title="simple alpha blending">Section 14.2 Simple alpha compositing</a> of <a data-link-type="biblio" href="#biblio-svg11">[SVG11]</a> and <a href="https://www.w3.org/TR/css3-color/#alpha" title="simple alpha compositing">simple alpha compositing</a> of <a data-link-type="biblio" href="#biblio-css3color">[CSS3COLOR]</a>.</p>
<p>This module also extends the <code class="idl"><a data-link-type="idl" href="https://html.spec.whatwg.org/multipage/canvas.html#dom-context-2d-globalcompositeoperation" id="ref-for-dom-context-2d-globalcompositeoperation①">globalCompositeOperation</a></code>.</p>
<h3 class="heading settled" data-level="2.2" id="values"><span class="secno">2.2. </span><span class="content">Values</span><a class="self-link" href="#values"></a></h3>
<p>This specification follows the <span spec-section="#property-defs">CSS property
definition conventions</span>. Value types not defined in
this specification are defined in CSS Level 2 Revision 1 <a data-link-type="biblio" href="#biblio-css21">[CSS21]</a>. Other CSS
modules may expand the definitions of these value types: for example <a data-link-type="biblio" href="#biblio-css3color">[CSS3COLOR]</a>,
when combined with this module, expands the definition of the <color>
value type as used in this specification.</p>
<p>In addition to the property-specific values listed in their definitions,
all properties defined in this specification also accept the <a data-link-type="dfn" href="https://drafts.csswg.org/css-cascade-3/#inheritance" id="ref-for-inheritance">inherit</a> keyword as their property value. For readability it has not been repeated
explicitly.</p>
<h2 class="heading settled" data-level="3" id="csscompositingandblending"><span class="secno">3. </span><span class="content">Specifying Blending in CSS </span><a class="self-link" href="#csscompositingandblending"></a></h2>
<h3 class="heading settled" data-level="3.1" id="compositingandblendingorder"><span class="secno">3.1. </span><span class="content">Order of graphical operations</span><a class="self-link" href="#compositingandblendingorder"></a></h3>
<p>The compositing model must follow the <a href="https://www.w3.org/TR/SVG11/render.html#Introduction">SVG compositing</a> model <a data-link-type="biblio" href="#biblio-svg11">[SVG11]</a>: first any filter effect is applied, then any clipping, masking, blending and compositing.</p>
<h3 class="heading settled" data-level="3.2" id="csscompositingrules_CSS"><span class="secno">3.2. </span><span class="content">Behavior specific to HTML</span><a class="self-link" href="#csscompositingrules_CSS"></a></h3>
<p>Everything in CSS that creates a <a data-link-type="dfn" href="https://drafts.csswg.org/css2/#stacking-context" id="ref-for-stacking-context①">stacking context</a> must be considered an <a href="#isolatedgroups">‘isolated’ group</a>. HTML elements themselves should not create groups.</p>
<p>An element that has blending applied, must blend with all the underlying content of the <a data-link-type="dfn" href="https://drafts.csswg.org/css2/#stacking-context" id="ref-for-stacking-context②">stacking context</a> that that element belongs to.</p>
<p>The root element for an HTML document is the <a href="https://dom.spec.whatwg.org/#document-element">document element</a>.</p>
<h3 class="heading settled" data-level="3.3" id="csscompositingrules_SVG"><span class="secno">3.3. </span><span class="content">Behavior specific to SVG</span><a class="self-link" href="#csscompositingrules_SVG"></a></h3>
<p>By default, every element must create a <a href="#isolatedgroups">non-isolated group</a>.</p>
<p>However, certain operations in SVG will create <a href="#isolatedgroups">isolated groups</a>. If one of the following features is used, the group must become isolated:</p>
<ul>
<li>opacity
<li>filters
<li>3D transforms (2D transforms must NOT cause isolation)
<li>blending
<li>masking
</ul>
<p>The root element for SVG is the <a href="https://www.w3.org/TR/SVG11/struct.html#NewDocument">SVG element</a>.</p>
<h3 class="heading settled" data-level="3.4" id="csskeywords"><span class="secno">3.4. </span><span class="content">CSS Properties</span><a class="self-link" href="#csskeywords"></a></h3>
<h4 class="heading settled" data-level="3.4.1" id="mix-blend-mode"><span class="secno">3.4.1. </span><span class="content">The <a class="property" data-link-type="propdesc" href="#propdef-mix-blend-mode" id="ref-for-propdef-mix-blend-mode">mix-blend-mode</a> property</span><a class="self-link" href="#mix-blend-mode"></a></h4>
<div class="mdn-anno wrapped after">
<button class="mdn-anno-btn"><b class="all-engines-flag" title="This feature is in all current engines.">✔</b><span>MDN</span></button>
<div class="feature">
<p><a href="https://developer.mozilla.org/en-US/docs/Web/CSS/mix-blend-mode" title="The mix-blend-mode CSS property sets how an element's content should blend with the content of the element's parent and the element's background.">mix-blend-mode</a></p>
<p class="all-engines-text">In all current engines.</p>
<div class="support">
<span class="firefox yes"><span>Firefox</span><span>32+</span></span><span class="safari yes"><span>Safari</span><span>8+</span></span><span class="chrome yes"><span>Chrome</span><span>41+</span></span>
<hr>
<span class="opera yes"><span>Opera</span><span>28+</span></span><span class="edge_blink yes"><span>Edge</span><span>79+</span></span>
<hr>
<span class="edge no"><span>Edge (Legacy)</span><span>None</span></span><span class="ie no"><span>IE</span><span>None</span></span>
<hr>
<span class="firefox_android yes"><span>Firefox for Android</span><span>32+</span></span><span class="safari_ios yes"><span>iOS Safari</span><span>8+</span></span><span class="chrome_android yes"><span>Chrome for Android</span><span>41+</span></span><span class="webview_android yes"><span>Android WebView</span><span>41+</span></span><span class="samsunginternet_android yes"><span>Samsung Internet</span><span>4.0+</span></span><span class="opera_android yes"><span>Opera Mobile</span><span>28+</span></span>
</div>
</div>
</div>
<p>The blend mode defines the formula that must be used to mix the colors with the backdrop.
This behavior is described in more detail in <a href="#blending">Blending</a>.</p>
<table class="def propdef" data-link-for-hint="mix-blend-mode">
<tbody>
<tr>
<th>Name:
<td><dfn class="dfn-paneled css" data-dfn-type="property" data-export id="propdef-mix-blend-mode">mix-blend-mode</dfn>
<tr class="value">
<th><a href="https://www.w3.org/TR/css-values/#value-defs">Value:</a>
<td class="prod"><a class="production css" data-link-type="type" href="#ltblendmodegt" id="ref-for-ltblendmodegt" title="Expands to: color | color-burn | color-dodge | darken | difference | exclusion | hard-light | hue | lighten | luminosity | multiply | normal | overlay | saturation | screen | soft-light"><blend-mode></a> <a data-link-type="grammar" href="https://drafts.csswg.org/css-values-4/#comb-one" id="ref-for-comb-one">|</a> <a data-link-type="dfn" href="#plus-darker" id="ref-for-plus-darker">plus-darker</a> <span id="ref-for-comb-one①">|</span> <a data-link-type="dfn" href="#plus-lighter" id="ref-for-plus-lighter">plus-lighter</a>
<tr>
<th><a href="https://www.w3.org/TR/css-cascade/#initial-values">Initial:</a>
<td>normal
<tr>
<th><a href="https://www.w3.org/TR/css-cascade/#applies-to">Applies to:</a>
<td>All elements. In SVG, it applies to <a href="https://www.w3.org/TR/SVG/intro.html#TermContainerElement">container elements</a>, <a href="https://www.w3.org/TR/SVG/intro.html#TermGraphicsElement">graphics elements</a> and <a href="https://www.w3.org/TR/2011/REC-SVG11-20110816/intro.html#TermGraphicsReferencingElement">graphics referencing elements</a>. <a data-link-type="biblio" href="#biblio-svg11">[SVG11]</a>
<tr>
<th><a href="https://www.w3.org/TR/css-cascade/#inherited-property">Inherited:</a>
<td>no
<tr>
<th><a href="https://www.w3.org/TR/css-values/#percentages">Percentages:</a>
<td>N/A
<tr>
<th><a href="https://www.w3.org/TR/css-cascade/#computed">Computed value:</a>
<td>as specified
<tr>
<th><a href="https://www.w3.org/TR/cssom/#serializing-css-values">Canonical order:</a>
<td>per grammar
<tr>
<th>Media:
<td>visual
<tr>
<th><a href="https://www.w3.org/TR/web-animations/#animation-type">Animatable:</a>
<td>no
</table>
<p>The syntax of the property of <a class="production css" data-link-type="type" href="#ltblendmodegt" id="ref-for-ltblendmodegt①" title="Expands to: color | color-burn | color-dodge | darken | difference | exclusion | hard-light | hue | lighten | luminosity | multiply | normal | overlay | saturation | screen | soft-light"><blend-mode></a> is given with:</p>
<div class="mdn-anno wrapped">
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<div class="feature">
<p><a href="https://developer.mozilla.org/en-US/docs/Web/CSS/blend-mode" title="The <blend-mode> CSS data type describes how colors should appear when elements overlap. It is used in the background-blend-mode and mix-blend-mode properties.">blend-mode</a></p>
<p class="all-engines-text">In all current engines.</p>
<div class="support">
<span class="firefox yes"><span>Firefox</span><span>30+</span></span><span class="safari yes"><span>Safari</span><span>8+</span></span><span class="chrome yes"><span>Chrome</span><span>35+</span></span>
<hr>
<span class="opera yes"><span>Opera</span><span>22+</span></span><span class="edge_blink yes"><span>Edge</span><span>79+</span></span>
<hr>
<span class="edge no"><span>Edge (Legacy)</span><span>None</span></span><span class="ie no"><span>IE</span><span>None</span></span>
<hr>
<span class="firefox_android yes"><span>Firefox for Android</span><span>54+</span></span><span class="safari_ios yes"><span>iOS Safari</span><span>8+</span></span><span class="chrome_android yes"><span>Chrome for Android</span><span>59+</span></span><span class="webview_android yes"><span>Android WebView</span><span>59+</span></span><span class="samsunginternet_android yes"><span>Samsung Internet</span><span>7.0+</span></span><span class="opera_android yes"><span>Opera Mobile</span><span>22+</span></span>
</div>
</div>
</div>
<pre class="blendmode prod"><dfn class="dfn-paneled" data-dfn-type="type" data-export id="ltblendmodegt"><blend-mode></dfn> = <a data-link-type="value" href="#valdef-blend-mode-normal" id="ref-for-valdef-blend-mode-normal">normal</a> <a data-link-type="grammar" href="https://drafts.csswg.org/css-values-4/#comb-one" id="ref-for-comb-one②">|</a> <a data-link-type="value" href="#valdef-blend-mode-multiply" id="ref-for-valdef-blend-mode-multiply">multiply</a> <a data-link-type="grammar" href="https://drafts.csswg.org/css-values-4/#comb-one" id="ref-for-comb-one③">|</a> <a data-link-type="value" href="#valdef-blend-mode-screen" id="ref-for-valdef-blend-mode-screen">screen</a> <a data-link-type="grammar" href="https://drafts.csswg.org/css-values-4/#comb-one" id="ref-for-comb-one④">|</a> <a data-link-type="value" href="#valdef-blend-mode-overlay" id="ref-for-valdef-blend-mode-overlay">overlay</a> <a data-link-type="grammar" href="https://drafts.csswg.org/css-values-4/#comb-one" id="ref-for-comb-one⑤">|</a> <a data-link-type="value" href="#valdef-blend-mode-darken" id="ref-for-valdef-blend-mode-darken">darken</a> <a data-link-type="grammar" href="https://drafts.csswg.org/css-values-4/#comb-one" id="ref-for-comb-one⑥">|</a> <a data-link-type="value" href="#valdef-blend-mode-lighten" id="ref-for-valdef-blend-mode-lighten">lighten</a> <a data-link-type="grammar" href="https://drafts.csswg.org/css-values-4/#comb-one" id="ref-for-comb-one⑦">|</a> <a data-link-type="value" href="#valdef-blend-mode-color-dodge" id="ref-for-valdef-blend-mode-color-dodge">color-dodge</a> <a data-link-type="grammar" href="https://drafts.csswg.org/css-values-4/#comb-one" id="ref-for-comb-one⑧">|</a><a data-link-type="value" href="#valdef-blend-mode-color-burn" id="ref-for-valdef-blend-mode-color-burn">color-burn</a> <a data-link-type="grammar" href="https://drafts.csswg.org/css-values-4/#comb-one" id="ref-for-comb-one⑨">|</a> <a data-link-type="value" href="#valdef-blend-mode-hard-light" id="ref-for-valdef-blend-mode-hard-light">hard-light</a> <a data-link-type="grammar" href="https://drafts.csswg.org/css-values-4/#comb-one" id="ref-for-comb-one①⓪">|</a> <a data-link-type="value" href="#valdef-blend-mode-soft-light" id="ref-for-valdef-blend-mode-soft-light">soft-light</a> <a data-link-type="grammar" href="https://drafts.csswg.org/css-values-4/#comb-one" id="ref-for-comb-one①①">|</a> <a data-link-type="value" href="#valdef-blend-mode-difference" id="ref-for-valdef-blend-mode-difference">difference</a> <a data-link-type="grammar" href="https://drafts.csswg.org/css-values-4/#comb-one" id="ref-for-comb-one①②">|</a> <a data-link-type="value" href="#valdef-blend-mode-exclusion" id="ref-for-valdef-blend-mode-exclusion">exclusion</a> <a data-link-type="grammar" href="https://drafts.csswg.org/css-values-4/#comb-one" id="ref-for-comb-one①③">|</a> <a data-link-type="value" href="#valdef-blend-mode-hue" id="ref-for-valdef-blend-mode-hue">hue</a> <a data-link-type="grammar" href="https://drafts.csswg.org/css-values-4/#comb-one" id="ref-for-comb-one①④">|</a>
<a data-link-type="value" href="#valdef-blend-mode-saturation" id="ref-for-valdef-blend-mode-saturation">saturation</a> <a data-link-type="grammar" href="https://drafts.csswg.org/css-values-4/#comb-one" id="ref-for-comb-one①⑤">|</a> <a data-link-type="value" href="#valdef-blend-mode-color" id="ref-for-valdef-blend-mode-color">color</a> <a data-link-type="grammar" href="https://drafts.csswg.org/css-values-4/#comb-one" id="ref-for-comb-one①⑥">|</a> <a data-link-type="value" href="#valdef-blend-mode-luminosity" id="ref-for-valdef-blend-mode-luminosity">luminosity</a></pre>
<p class="note" role="note"><span>Note:</span> Applying a blendmode other than <a class="css" data-link-type="value" href="#valdef-blend-mode-normal" id="ref-for-valdef-blend-mode-normal①">normal</a> to the element must establish a new <a data-link-type="dfn" href="https://drafts.csswg.org/css2/#stacking-context" id="ref-for-stacking-context③">stacking context</a>. This group must then be blended and composited with the <span id="ref-for-stacking-context④">stacking context</span> that contains the element.</p>
<div class="example" id="example-7e584e42">
<a class="self-link" href="#example-7e584e42"></a>
<p>Given the following sample markup:</p>
<pre><body>
<img src="ducky.png"/>
</body>
</pre>
<p>And the following style rule:</p>
<pre>body { background-color: lime; }
</pre>
<p> ... will produce the following result: </p>
<div class="figure">
<img alt="example of an image of duck with the lime color of the document" height="537" src="examples/ducky_normal.png" style="width:30%" width="489">
<p class="caption"> Partially transparent image on a lime backdrop</p>
</div>
<p>If we change the style rule to include blending:</p>
<pre>body { background-color: lime; }
img { mix-blend-mode: multiply; }
</pre>
<p> ... the output will be the image blending with the lime background of the <body> element. </p>
<div class="figure">
<img alt="example of an image of duck blending with the lime color of the document" height="537" src="examples/ducky_multiply.png" style="width:30%" width="489">
<p class="caption"> Blending of a transparent image on a lime backdrop. </p>
</div>
</div>
<div class="example" id="example-cc75cc4f">
<a class="self-link" href="#example-cc75cc4f"></a>
<p>Given the following svg code:</p>
<pre><svg>
<circle cx="40" cy="40" r="40" fill="red"/>
<circle cx="80" cy="40" r="40" fill="lime"/>
<circle cx="60" cy="80" r="40" fill="blue"/>
</svg>
</pre>
<p>And the following style rule:</p>
<pre>circle { mix-blend-mode: screen; }
</pre>
<p> ... the output will be blending of the 3 circles. Each circle is rendered from bottom to top. Where the elements overlap, the blend mode produces a change in color. </p>
<div class="figure">
<img alt="example of 3 circles blending with a screen blend mode" src="examples/screen_example.svg" style="width:30%">
<p class="caption"> Example of 3 circles blending with a screen blend mode </p>
</div>
</div>
<div class="example" id="example-0c443386">
<a class="self-link" href="#example-0c443386"></a>
<p>In the following style sheet and document fragment:</p>
<pre>body { background-color: lime; }
div { background-color: red; width: 200px; opacity: .95}
img { mix-blend-mode: difference; }
<body>
<div>
<img src="ducky.png"/>
</div>
</body>
</pre>
<p> ... the <a class="property" data-link-type="propdesc" href="https://drafts.csswg.org/css-color-4/#propdef-opacity" id="ref-for-propdef-opacity">opacity</a> on the <div> element is causing the creation of a stacking context. This causes the creation of a new group so the image doesn’t blend with the color of the <body>. </p>
<div class="figure">
<img alt="example of an image of duck blending with the lime color of the document" height="537" src="examples/ducky_difference.png" style="width:30%" width="489">
<p class="caption"> Example of blending within a stacking context.</p>
</div>
<p> Note how the image is not blending with the lime color. </p>
</div>
<div class="example" id="example-f6e93bc6">
<a class="self-link" href="#example-f6e93bc6"></a>
<p>Given the following sample markup:</p>
<pre><body>
<div>
<p><a class="css" data-link-type="maybe" href="#valdef-blend-mode-overlay" id="ref-for-valdef-blend-mode-overlay①">overlay</a> blending on text</p>
</div>
</body>
</pre>
<p>And the following style rule:</p>
<pre>div { background-image: url('texture.png'); }
@font-face {
font-family: "Mythos Std";
src: url("http://myfontvendor.com/mythos.otf");
}
p {
mix-blend-mode: overlay;
font-family: "Mythos Std"
}
</pre>
<div class="figure">
<img alt="example of text that has an overlay blend on top of a texture" height="295" src="examples/overlay_text.png" style="width:75%" width="510">
<p class="caption"> Text with a blend overlay on top of an image. </p>
</div>
</div>
<h4 class="heading settled" data-level="3.4.2" id="isolation"><span class="secno">3.4.2. </span><span class="content">The <a class="property" data-link-type="propdesc" href="#propdef-isolation" id="ref-for-propdef-isolation">isolation</a> property</span><a class="self-link" href="#isolation"></a></h4>
<div class="mdn-anno wrapped after">
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<div class="feature">
<p><a href="https://developer.mozilla.org/en-US/docs/Web/CSS/isolation" title="The isolation CSS property determines whether an element must create a new stacking context.">isolation</a></p>
<p class="all-engines-text">In all current engines.</p>
<div class="support">
<span class="firefox yes"><span>Firefox</span><span>36+</span></span><span class="safari yes"><span>Safari</span><span>8+</span></span><span class="chrome yes"><span>Chrome</span><span>41+</span></span>
<hr>
<span class="opera yes"><span>Opera</span><span>30+</span></span><span class="edge_blink yes"><span>Edge</span><span>79+</span></span>
<hr>
<span class="edge no"><span>Edge (Legacy)</span><span>None</span></span><span class="ie no"><span>IE</span><span>None</span></span>
<hr>
<span class="firefox_android yes"><span>Firefox for Android</span><span>36+</span></span><span class="safari_ios yes"><span>iOS Safari</span><span>8+</span></span><span class="chrome_android yes"><span>Chrome for Android</span><span>41+</span></span><span class="webview_android yes"><span>Android WebView</span><span>41+</span></span><span class="samsunginternet_android yes"><span>Samsung Internet</span><span>4.0+</span></span><span class="opera_android yes"><span>Opera Mobile</span><span>30+</span></span>
</div>
</div>
</div>
<p>In SVG, this defines whether an element is isolated or not.<br> For CSS, setting <a class="property" data-link-type="propdesc" href="#propdef-isolation" id="ref-for-propdef-isolation①">isolation</a> to <span class="css">isolate</span> will turn the element into a stacking context.</p>
<p>By default, elements use the <span class="css">auto</span> keyword which implies that they are not isolated. However operations that cause the creation of <a data-link-type="dfn" href="https://drafts.csswg.org/css2/#stacking-context" id="ref-for-stacking-context⑤">stacking context</a> must cause a group to be isolated. These operations are described in <a href="#csscompositingrules_CSS">'behavior specific to HTML'</a> and <a href="#csscompositingrules_SVG">'behavior specific to SVG'</a>.</p>
<table class="def propdef" data-link-for-hint="isolation">
<tbody>
<tr>
<th>Name:
<td><dfn class="dfn-paneled css" data-dfn-type="property" data-export id="propdef-isolation">isolation</dfn>
<tr class="value">
<th><a href="https://www.w3.org/TR/css-values/#value-defs">Value:</a>
<td class="prod"><a class="production css" data-link-type="type" href="#isolated-propid" id="ref-for-isolated-propid"><isolation-mode></a>
<tr>
<th><a href="https://www.w3.org/TR/css-cascade/#initial-values">Initial:</a>
<td>auto
<tr>
<th><a href="https://www.w3.org/TR/css-cascade/#applies-to">Applies to:</a>
<td>All elements. In SVG, it applies to <a href="https://www.w3.org/TR/SVG/intro.html#TermContainerElement">container elements</a>, <a href="https://www.w3.org/TR/SVG/intro.html#TermGraphicsElement">graphics elements</a> and <a href="https://www.w3.org/TR/2011/REC-SVG11-20110816/intro.html#TermGraphicsReferencingElement">graphics referencing elements</a>. <a data-link-type="biblio" href="#biblio-svg11">[SVG11]</a>
<tr>
<th><a href="https://www.w3.org/TR/css-cascade/#inherited-property">Inherited:</a>
<td>no
<tr>
<th><a href="https://www.w3.org/TR/css-values/#percentages">Percentages:</a>
<td>N/A
<tr>
<th><a href="https://www.w3.org/TR/css-cascade/#computed">Computed value:</a>
<td>as specified
<tr>
<th><a href="https://www.w3.org/TR/cssom/#serializing-css-values">Canonical order:</a>
<td>per grammar
<tr>
<th>Media:
<td>visual
<tr>
<th><a href="https://www.w3.org/TR/web-animations/#animation-type">Animatable:</a>
<td>no
</table>
<p>The syntax of the property of <a class="production css" data-link-type="type" href="#isolated-propid" id="ref-for-isolated-propid①"><isolation-mode></a> is given with:</p>
<pre class="isolated prod"><dfn class="dfn-paneled" data-dfn-type="type" data-export id="isolated-propid"><isolation-mode></dfn> = auto <a data-link-type="grammar" href="https://drafts.csswg.org/css-values-4/#comb-one" id="ref-for-comb-one①⑦">|</a> isolate</pre>
<p id="img_isolation"> In CSS, a background image or the content of an <a data-link-type="element" href="https://html.spec.whatwg.org/multipage/embedded-content.html#the-img-element" id="ref-for-the-img-element">img</a> must always be rendered into an isolated group.<br>For instance, if you link to an SVG file through the <span id="ref-for-the-img-element①">img</span> tag, the artwork of that SVG will not blend with the backdrop of the content.</p>
<p>In SVG, <a class="property" data-link-type="propdesc" href="https://www.w3.org/TR/SVG11/masking.html#MaskProperty" id="ref-for-MaskProperty">mask</a> always creates an isolated group.</p>
<h4 class="heading settled" data-level="3.4.3" id="background-blend-mode"><span class="secno">3.4.3. </span><span class="content">The <a class="property" data-link-type="propdesc" href="#propdef-background-blend-mode" id="ref-for-propdef-background-blend-mode①">background-blend-mode</a> property</span><a class="self-link" href="#background-blend-mode"></a></h4>
<div class="mdn-anno wrapped after">
<button class="mdn-anno-btn"><b class="all-engines-flag" title="This feature is in all current engines.">✔</b><span>MDN</span></button>
<div class="feature">
<p><a href="https://developer.mozilla.org/en-US/docs/Web/CSS/background-blend-mode" title="The background-blend-mode CSS property sets how an element's background images should blend with each other and with the element's background color.">background-blend-mode</a></p>
<p class="all-engines-text">In all current engines.</p>
<div class="support">
<span class="firefox yes"><span>Firefox</span><span>30+</span></span><span class="safari yes"><span>Safari</span><span>8+</span></span><span class="chrome yes"><span>Chrome</span><span>35+</span></span>
<hr>
<span class="opera yes"><span>Opera</span><span>22+</span></span><span class="edge_blink yes"><span>Edge</span><span>79+</span></span>
<hr>
<span class="edge no"><span>Edge (Legacy)</span><span>None</span></span><span class="ie no"><span>IE</span><span>None</span></span>
<hr>
<span class="firefox_android yes"><span>Firefox for Android</span><span>30+</span></span><span class="safari_ios yes"><span>iOS Safari</span><span>8+</span></span><span class="chrome_android yes"><span>Chrome for Android</span><span>35+</span></span><span class="webview_android yes"><span>Android WebView</span><span>37+</span></span><span class="samsunginternet_android yes"><span>Samsung Internet</span><span>3.0+</span></span><span class="opera_android yes"><span>Opera Mobile</span><span>22+</span></span>
</div>
</div>
</div>
<p>Defines the blending mode of each background layer.</p>
<p>Each background layer must blend with the element’s background layer that is below it and the element’s background color. Background layers must not blend with the content that is behind the element, instead they must act as if they are rendered into an isolated group.</p>
<p>The description of the <a class="property" data-link-type="propdesc" href="#propdef-background-blend-mode" id="ref-for-propdef-background-blend-mode②">background-blend-mode</a> property is as follows:</p>
<table class="def propdef" data-link-for-hint="background-blend-mode">
<tbody>
<tr>
<th>Name:
<td><dfn class="dfn-paneled css" data-dfn-type="property" data-export id="propdef-background-blend-mode">background-blend-mode</dfn>
<tr class="value">
<th><a href="https://www.w3.org/TR/css-values/#value-defs">Value:</a>
<td class="prod"><<a class="property" data-link-type="propdesc" href="#propdef-mix-blend-mode" id="ref-for-propdef-mix-blend-mode①">mix-blend-mode</a>><a data-link-type="grammar" href="https://drafts.csswg.org/css-values-4/#mult-comma" id="ref-for-mult-comma">#</a>
<tr>
<th><a href="https://www.w3.org/TR/css-cascade/#initial-values">Initial:</a>