| CARVIEW |
Select Language
HTTP/2 200
content-type: text/html
x-guploader-uploadid: AAwnv3KFURQ3n7UJO3KNorLEVvIFnz4YydAEpYde5guBYO-lcWfez1CjJgNmw6snuGJ88Nc_
cache-control: public, max-age=3600
expires: Wed, 08 Oct 2025 22:47:31 GMT
last-modified: Wed, 08 Oct 2025 01:04:47 GMT
etag: W/"55ae2d2994e9d612d842509d906aee6f"
x-goog-generation: 1759885487045314
x-goog-metageneration: 1
x-goog-stored-content-encoding: identity
x-goog-stored-content-length: 143730
x-goog-meta-goog-reserved-file-mtime: 1759884012
x-goog-hash: crc32c=ZApnnA==, md5=Va4tKZTp1hLYQlCdkGrubw==
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: c40fcbe0e49d94a7f0fcd1e55ded22c7
date: Wed, 08 Oct 2025 21:47:32 GMT
server: Google Frontend
via: 1.1 google
vary: Accept-Encoding
content-encoding: gzip
x-cache: miss
Firefox 85 for developers - Mozilla | MDN
Toggle sidebar
Firefox 85 for developers
This article provides information about the changes in Firefox 85 that will affect developers. Firefox 85 was released on January 26, 2021.
Note: See also January brings us Firefox 85 on Mozilla Hacks.
Changes for web developers
Developer Tools
- Developers can now use the Page Inspector to toggle the
:focus-visiblepseudo-class for the currently selected element (in addition to the pseudo classes that were previously supported::hover,:activeand:focus,:focus-within, and:visited). (Firefox bug 1617608).
HTML
<link rel="preload">is now enabled. (Firefox bug 1626997).
Removals
- The
<menuitem>HTML element is no longer available — it has been hidden behind thedom.menuitem.enabled flag. (Firefox bug 1680596).
CSS
- The
:focus-visiblepseudo-class is now enabled. (Firefox bug 1445482). - The
pinch-zoomvalue for thetouch-actionproperty is now enabled. (Firefox bug 1329241).
JavaScript
-
The
collationproperty can now be specified in the options passed to theIntl.Collator()constructor (Firefox bug 1670062). This allows developers to write code with greater clarity:js// Old method let pinyin = new Intl.Collator(["zh-u-co-pinyin"]); // New method let pinyin = new Intl.Collator("zh", { collation: "pinyin" });
Plugins
- Flash support has been completely removed from Firefox (Firefox bug 1675349).
APIs
No changes.
WebDriver conformance (Marionette)
- Fixed a potential page load timeout situation when
WebDriver:ElementClickis called for a link with atargetother than_blank(Firefox bug 1678455). - Using web element references on browsing contexts other than the originating one now correctly returns a
no such elementerror instead of astale element referenceerror (Firefox bug 1684827).
Known bugs
- WebDriver commands following a call to
WebDriver:SwitchToFramecan fail with a "no such window" error if the frame's content hasn't yet finished loading (Firefox bug 1691348). - After a cross-group page navigation, accessing a previously-retrieved element might not always raise a "stale element" error, and can also lead to a "no such element" error. To prevent this, set the
marionette.actors.enabledpreference tofalse(Firefox bug 1690308).
Changes for add-on developers
No changes.