HTTP/2 200
content-type: text/html
x-guploader-uploadid: AAwnv3KcDnsew_HDQbMfQMaR-53B0iBJ2SbPpRFK3SLEJ5wAhh8OPdqSG1fwcoBQYHjhW-cl
cache-control: public, max-age=3600
expires: Sun, 12 Oct 2025 08:51:33 GMT
last-modified: Fri, 10 Oct 2025 01:09:21 GMT
etag: W/"0a78424bc456bce9958bf88cee1f3c29"
x-goog-generation: 1760058561511409
x-goog-metageneration: 1
x-goog-stored-content-encoding: identity
x-goog-stored-content-length: 275541
x-goog-meta-goog-reserved-file-mtime: 1760056892
x-goog-hash: crc32c=H+D+rw==, md5=CnhCS8RWvOmVi/iM7h88KQ==
x-goog-storage-class: STANDARD
accept-ranges: none
alt-svc: h3=":443"; ma=2592000,h3-29=":443"; ma=2592000
alt-svc: clear
referrer-policy: strict-origin-when-cross-origin
x-content-type-options: nosniff
strict-transport-security: max-age=63072000
content-security-policy: default-src 'self'; script-src 'report-sample' 'self' 'wasm-unsafe-eval' https://www.google-analytics.com/analytics.js https://www.googletagmanager.com/gtag/js assets.codepen.io production-assets.codepen.io https://js.stripe.com 'sha256-XNBp89FG76amD8BqrJzyflxOF9PaWPqPqvJfKZPCv7M=' 'sha256-YCNoU9DNiinACbd8n6UPyB/8vj0kXvhkOni9/06SuYw=' 'sha256-PZjP7OR6mBEtnvXIZfCZ5PuOlxoDF1LDZL8aj8c42rw='; script-src-elem 'report-sample' 'self' 'wasm-unsafe-eval' https://www.google-analytics.com/analytics.js https://www.googletagmanager.com/gtag/js assets.codepen.io production-assets.codepen.io https://js.stripe.com 'sha256-XNBp89FG76amD8BqrJzyflxOF9PaWPqPqvJfKZPCv7M=' 'sha256-YCNoU9DNiinACbd8n6UPyB/8vj0kXvhkOni9/06SuYw=' 'sha256-PZjP7OR6mBEtnvXIZfCZ5PuOlxoDF1LDZL8aj8c42rw='; style-src 'report-sample' 'self' 'unsafe-inline'; object-src 'none'; base-uri 'self'; connect-src 'self' developer.allizom.org bcd.developer.allizom.org bcd.developer.mozilla.org updates.developer.allizom.org updates.developer.mozilla.org https://*.google-analytics.com https://*.analytics.google.com https://*.googletagmanager.com https://incoming.telemetry.mozilla.org https://observatory-api.mdn.allizom.net https://observatory-api.mdn.mozilla.net https://api.github.com/search/issues stats.g.doubleclick.net https://api.stripe.com; font-src 'self'; frame-src 'self' interactive-examples.mdn.mozilla.net interactive-examples.mdn.allizom.net mdn.github.io live-samples.mdn.mozilla.net live-samples.mdn.allizom.net *.mdnplay.dev *.mdnyalp.dev *.play.test.mdn.allizom.net https://v2.scrimba.com https://scrimba.com jsfiddle.net www.youtube-nocookie.com codepen.io survey.alchemer.com https://js.stripe.com; img-src 'self' data: *.githubusercontent.com *.googleusercontent.com *.gravatar.com mozillausercontent.com firefoxusercontent.com profile.stage.mozaws.net profile.accounts.firefox.com developer.mozilla.org mdn.dev interactive-examples.mdn.mozilla.net interactive-examples.mdn.allizom.net wikipedia.org upload.wikimedia.org https://mdn.github.io/shared-assets/ https://mdn.dev/ https://*.google-analytics.com https://*.googletagmanager.com www.gstatic.com; manifest-src 'self'; media-src 'self' archive.org videos.cdn.mozilla.net https://mdn.github.io/shared-assets/; child-src 'self'; worker-src 'self';
x-frame-options: DENY
origin-trial: AxVILwizhbMjxFeHOn1P3R8niO1RJY/smaK4B4d1rLzc1gTaxtXMSaTi+FoigYgCw40uFRDwFcEAeqDR+vVLOW4AAABfeyJvcmlnaW4iOiJodHRwczovL2RldmVsb3Blci5tb3ppbGxhLm9yZyIsImZlYXR1cmUiOiJQcml2YXRlQXR0cmlidXRpb25WMiIsImV4cGlyeSI6MTc0MjA3OTYwMH0=
x-cloud-trace-context: 4388fa4b2dc8997908a93c224c0186d3
date: Sun, 12 Oct 2025 07:51:34 GMT
server: Google Frontend
via: 1.1 google
vary: Accept-Encoding
content-encoding: gzip
x-cache: miss
opacity() - CSS | MDN
<section id="default-example">
<img
class="transition-all"
id="example-element"
src="/shared-assets/images/examples/firefox-logo.svg"
width="200" />
</section>
Note :
Cette fonction est proche de la propriété opacity
mais, selon le navigateur, les filtres CSS peuvent bénéficier de l'accélération matérielle pour de meilleures performances.
multiplicateur
L'intensité de l'opacité, indiquée comme un nombre (<number>
) ou comme un pourcentage (<percentage>
). Une valeur de 0%
entraînera une image complètement transparente. Une valeur de 100%
laissera l'image inchangée. Les valeurs intermédiaires auront un effet proportionnel. Lors d'une interpolation, la valeur par défaut utilisée sera 1
.
opacity(0%); /* Complètement transparente */
opacity(50%); /* 50% transparent */
opacity(1); /* Aucun effet */