Updates for Firefox 147 beta by Elchi3 · Pull Request #28624 · mdn/browser-compat-data

Elchi3 · 2025-12-09T15:03:10Z

The https://collector.openwebdocs.org/ project (v10.16.2) found new features shipping in Firefox 147 beta which was released today Currently, the collector covers about 90% of BCD, so the following list might not be exhaustive. Also, if a feature is in Firefox Nightly only, it is not considered here.

With this PR, BCD considers the following 422 features as shipping in Firefox 147:

api.CSSPositionTryDescriptors
api.CSSPositionTryDescriptors.align-self
api.CSSPositionTryDescriptors.alignSelf
api.CSSPositionTryDescriptors.block-size
api.CSSPositionTryDescriptors.blockSize
api.CSSPositionTryDescriptors.bottom
api.CSSPositionTryDescriptors.height
api.CSSPositionTryDescriptors.inline-size
api.CSSPositionTryDescriptors.inlineSize
api.CSSPositionTryDescriptors.inset
api.CSSPositionTryDescriptors.inset-block
api.CSSPositionTryDescriptors.inset-block-end
api.CSSPositionTryDescriptors.inset-block-start
api.CSSPositionTryDescriptors.inset-inline
api.CSSPositionTryDescriptors.inset-inline-end
api.CSSPositionTryDescriptors.inset-inline-start
api.CSSPositionTryDescriptors.insetBlock
api.CSSPositionTryDescriptors.insetBlockEnd
api.CSSPositionTryDescriptors.insetBlockStart
api.CSSPositionTryDescriptors.insetInline
api.CSSPositionTryDescriptors.insetInlineEnd
api.CSSPositionTryDescriptors.insetInlineStart
api.CSSPositionTryDescriptors.justify-self
api.CSSPositionTryDescriptors.justifySelf
api.CSSPositionTryDescriptors.left
api.CSSPositionTryDescriptors.margin
api.CSSPositionTryDescriptors.margin-block
api.CSSPositionTryDescriptors.margin-block-end
api.CSSPositionTryDescriptors.margin-block-start
api.CSSPositionTryDescriptors.margin-bottom
api.CSSPositionTryDescriptors.margin-inline
api.CSSPositionTryDescriptors.margin-inline-end
api.CSSPositionTryDescriptors.margin-inline-start
api.CSSPositionTryDescriptors.margin-left
api.CSSPositionTryDescriptors.margin-right
api.CSSPositionTryDescriptors.margin-top
api.CSSPositionTryDescriptors.marginBlock
api.CSSPositionTryDescriptors.marginBlockEnd
api.CSSPositionTryDescriptors.marginBlockStart
api.CSSPositionTryDescriptors.marginBottom
api.CSSPositionTryDescriptors.marginInline
api.CSSPositionTryDescriptors.marginInlineEnd
api.CSSPositionTryDescriptors.marginInlineStart
api.CSSPositionTryDescriptors.marginLeft
api.CSSPositionTryDescriptors.marginRight
api.CSSPositionTryDescriptors.marginTop
api.CSSPositionTryDescriptors.max-block-size
api.CSSPositionTryDescriptors.max-height
api.CSSPositionTryDescriptors.max-inline-size
api.CSSPositionTryDescriptors.max-width
api.CSSPositionTryDescriptors.maxBlockSize
api.CSSPositionTryDescriptors.maxHeight
api.CSSPositionTryDescriptors.maxInlineSize
api.CSSPositionTryDescriptors.maxWidth
api.CSSPositionTryDescriptors.min-block-size
api.CSSPositionTryDescriptors.min-height
api.CSSPositionTryDescriptors.min-inline-size
api.CSSPositionTryDescriptors.min-width
api.CSSPositionTryDescriptors.minBlockSize
api.CSSPositionTryDescriptors.minHeight
api.CSSPositionTryDescriptors.minInlineSize
api.CSSPositionTryDescriptors.minWidth
api.CSSPositionTryDescriptors.place-self
api.CSSPositionTryDescriptors.placeSelf
api.CSSPositionTryDescriptors.position-anchor
api.CSSPositionTryDescriptors.position-area
api.CSSPositionTryDescriptors.positionAnchor
api.CSSPositionTryDescriptors.positionArea
api.CSSPositionTryDescriptors.right
api.CSSPositionTryDescriptors.top
api.CSSPositionTryDescriptors.width
api.CSSPositionTryRule
api.CSSPositionTryRule.name
api.CSSPositionTryRule.style
api.Document.activeViewTransition
api.Element.setHTML
api.NavigateEvent
api.NavigateEvent.NavigateEvent
api.NavigateEvent.canIntercept
api.NavigateEvent.destination
api.NavigateEvent.downloadRequest
api.NavigateEvent.formData
api.NavigateEvent.hashChange
api.NavigateEvent.hasUAVisualTransition
api.NavigateEvent.info
api.NavigateEvent.intercept
api.NavigateEvent.navigationType
api.NavigateEvent.scroll
api.NavigateEvent.signal
api.NavigateEvent.sourceElement
api.NavigateEvent.userInitiated
api.Navigation
api.Navigation.activation
api.Navigation.back
api.Navigation.canGoBack
api.Navigation.canGoForward
api.Navigation.currentEntry
api.Navigation.entries
api.Navigation.forward
api.Navigation.navigate
api.Navigation.reload
api.Navigation.transition
api.Navigation.traverseTo
api.Navigation.updateCurrentEntry
api.NavigationActivation
api.NavigationActivation.entry
api.NavigationActivation.from
api.NavigationActivation.navigationType
api.NavigationCurrentEntryChangeEvent
api.NavigationCurrentEntryChangeEvent.NavigationCurrentEntryChangeEvent
api.NavigationCurrentEntryChangeEvent.from
api.NavigationCurrentEntryChangeEvent.navigationType
api.NavigationDestination
api.NavigationDestination.getState
api.NavigationDestination.id
api.NavigationDestination.index
api.NavigationDestination.key
api.NavigationDestination.sameDocument
api.NavigationDestination.url
api.NavigationHistoryEntry
api.NavigationHistoryEntry.dispose_event
api.NavigationHistoryEntry.getState
api.NavigationHistoryEntry.id
api.NavigationHistoryEntry.index
api.NavigationHistoryEntry.key
api.NavigationHistoryEntry.sameDocument
api.NavigationHistoryEntry.url
api.NavigationPrecommitController
api.NavigationPrecommitController.redirect
api.NavigationTransition
api.NavigationTransition.committed
api.NavigationTransition.finished
api.NavigationTransition.from
api.NavigationTransition.navigationType
api.Sanitizer
api.Sanitizer.Sanitizer
api.Sanitizer.allowAttribute
api.Sanitizer.allowElement
api.Sanitizer.get
api.Sanitizer.removeAttribute
api.Sanitizer.removeElement
api.Sanitizer.removeUnsafe
api.Sanitizer.replaceElementWithChildren
api.Sanitizer.setComments
api.Sanitizer.setDataAttributes
api.TrustedHTML
api.TrustedHTML.toJSON
api.TrustedHTML.toString
api.TrustedScript
api.TrustedScript.toJSON
api.TrustedScript.toString
api.TrustedScriptURL
api.TrustedScriptURL.toJSON
api.TrustedScriptURL.toString
api.TrustedTypePolicy
api.TrustedTypePolicy.createHTML
api.TrustedTypePolicy.createScript
api.TrustedTypePolicy.createScriptURL
api.TrustedTypePolicy.name
api.TrustedTypePolicyFactory
api.TrustedTypePolicyFactory.createPolicy
api.TrustedTypePolicyFactory.defaultPolicy
api.TrustedTypePolicyFactory.emptyHTML
api.TrustedTypePolicyFactory.emptyScript
api.TrustedTypePolicyFactory.getAttributeType
api.TrustedTypePolicyFactory.getPropertyType
api.TrustedTypePolicyFactory.isHTML
api.TrustedTypePolicyFactory.isScript
api.TrustedTypePolicyFactory.isScriptURL
api.ViewTransition.types
api.ViewTransitionTypeSet
api.ViewTransitionTypeSet.add
api.ViewTransitionTypeSet.clear
api.ViewTransitionTypeSet.delete
api.ViewTransitionTypeSet.entries
api.ViewTransitionTypeSet.forEach
api.ViewTransitionTypeSet.has
api.ViewTransitionTypeSet.keys
api.ViewTransitionTypeSet.size
api.ViewTransitionTypeSet.values
api.ViewTransitionTypeSet.@@iterator
api.Window.navigation
api.trustedTypes
css.properties.align-items.anchor-center
css.properties.align-self.anchor-center
css.properties.anchor-name
css.properties.anchor-name.none
css.properties.anchor-scope
css.properties.anchor-scope.all
css.properties.anchor-scope.none
css.properties.block-size.anchor-size
css.properties.bottom.anchor
css.properties.bottom.anchor-size
css.properties.height.anchor-size
css.properties.inline-size.anchor-size
css.properties.inset-block-end.anchor
css.properties.inset-block-end.anchor-size
css.properties.inset-block-start.anchor
css.properties.inset-block-start.anchor-size
css.properties.inset-block.anchor
css.properties.inset-block.anchor-size
css.properties.inset-inline-end.anchor
css.properties.inset-inline-end.anchor-size
css.properties.inset-inline-start.anchor
css.properties.inset-inline-start.anchor-size
css.properties.inset-inline.anchor
css.properties.inset-inline.anchor-size
css.properties.inset.anchor
css.properties.inset.anchor-size
css.properties.justify-items.anchor-center
css.properties.justify-self.anchor-center
css.properties.left.anchor
css.properties.left.anchor-size
css.properties.margin-block-end.anchor-size
css.properties.margin-block-start.anchor-size
css.properties.margin-block.anchor-size
css.properties.margin-bottom.anchor-size
css.properties.margin-inline-end.anchor-size
css.properties.margin-inline-start.anchor-size
css.properties.margin-inline.anchor-size
css.properties.margin-left.anchor-size
css.properties.margin-right.anchor-size
css.properties.margin-top.anchor-size
css.properties.margin.anchor-size
css.properties.max-block-size.anchor-size
css.properties.max-height.anchor-size
css.properties.max-inline-size.anchor-size
css.properties.max-width.anchor-size
css.properties.min-block-size.anchor-size
css.properties.min-height.anchor-size
css.properties.min-inline-size.anchor-size
css.properties.min-width.anchor-size
css.properties.place-items.anchor-center
css.properties.place-self.anchor-center
css.properties.position-anchor
css.properties.position-anchor.auto
css.properties.position-area
css.properties.position-area.block-end
css.properties.position-area.block-start
css.properties.position-area.bottom
css.properties.position-area.center
css.properties.position-area.end
css.properties.position-area.inline-end
css.properties.position-area.inline-start
css.properties.position-area.left
css.properties.position-area.none
css.properties.position-area.right
css.properties.position-area.self-block-end
css.properties.position-area.self-block-start
css.properties.position-area.self-end
css.properties.position-area.self-inline-end
css.properties.position-area.self-inline-start
css.properties.position-area.self-start
css.properties.position-area.self-x-end
css.properties.position-area.self-x-start
css.properties.position-area.self-y-end
css.properties.position-area.self-y-start
css.properties.position-area.span-all
css.properties.position-area.span-block-end
css.properties.position-area.span-block-start
css.properties.position-area.span-bottom
css.properties.position-area.span-end
css.properties.position-area.span-inline-end
css.properties.position-area.span-inline-start
css.properties.position-area.span-left
css.properties.position-area.span-right
css.properties.position-area.span-self-block-end
css.properties.position-area.span-self-block-start
css.properties.position-area.span-self-end
css.properties.position-area.span-self-inline-end
css.properties.position-area.span-self-inline-start
css.properties.position-area.span-self-start
css.properties.position-area.span-self-x-end
css.properties.position-area.span-self-x-start
css.properties.position-area.span-self-y-end
css.properties.position-area.span-self-y-start
css.properties.position-area.span-start
css.properties.position-area.span-top
css.properties.position-area.span-x-end
css.properties.position-area.span-x-start
css.properties.position-area.span-y-end
css.properties.position-area.span-y-start
css.properties.position-area.start
css.properties.position-area.top
css.properties.position-area.x-end
css.properties.position-area.x-start
css.properties.position-area.y-end
css.properties.position-area.y-start
css.properties.position-try-fallbacks
css.properties.position-try-fallbacks.block-end
css.properties.position-try-fallbacks.block-start
css.properties.position-try-fallbacks.bottom
css.properties.position-try-fallbacks.center
css.properties.position-try-fallbacks.end
css.properties.position-try-fallbacks.flip-block
css.properties.position-try-fallbacks.flip-inline
css.properties.position-try-fallbacks.flip-start
css.properties.position-try-fallbacks.flip-x
css.properties.position-try-fallbacks.flip-y
css.properties.position-try-fallbacks.inline-end
css.properties.position-try-fallbacks.inline-start
css.properties.position-try-fallbacks.left
css.properties.position-try-fallbacks.none
css.properties.position-try-fallbacks.position-area
css.properties.position-try-fallbacks.right
css.properties.position-try-fallbacks.self-block-end
css.properties.position-try-fallbacks.self-block-start
css.properties.position-try-fallbacks.self-end
css.properties.position-try-fallbacks.self-inline-end
css.properties.position-try-fallbacks.self-inline-start
css.properties.position-try-fallbacks.self-start
css.properties.position-try-fallbacks.self-x-end
css.properties.position-try-fallbacks.self-x-start
css.properties.position-try-fallbacks.self-y-end
css.properties.position-try-fallbacks.self-y-start
css.properties.position-try-fallbacks.span-all
css.properties.position-try-fallbacks.span-block-end
css.properties.position-try-fallbacks.span-block-start
css.properties.position-try-fallbacks.span-bottom
css.properties.position-try-fallbacks.span-end
css.properties.position-try-fallbacks.span-inline-end
css.properties.position-try-fallbacks.span-inline-start
css.properties.position-try-fallbacks.span-left
css.properties.position-try-fallbacks.span-right
css.properties.position-try-fallbacks.span-self-block-end
css.properties.position-try-fallbacks.span-self-block-start
css.properties.position-try-fallbacks.span-self-end
css.properties.position-try-fallbacks.span-self-inline-end
css.properties.position-try-fallbacks.span-self-inline-start
css.properties.position-try-fallbacks.span-self-start
css.properties.position-try-fallbacks.span-self-x-end
css.properties.position-try-fallbacks.span-self-x-start
css.properties.position-try-fallbacks.span-self-y-end
css.properties.position-try-fallbacks.span-self-y-start
css.properties.position-try-fallbacks.span-start
css.properties.position-try-fallbacks.span-top
css.properties.position-try-fallbacks.span-x-end
css.properties.position-try-fallbacks.span-x-start
css.properties.position-try-fallbacks.span-y-end
css.properties.position-try-fallbacks.span-y-start
css.properties.position-try-fallbacks.start
css.properties.position-try-fallbacks.top
css.properties.position-try-fallbacks.x-end
css.properties.position-try-fallbacks.x-start
css.properties.position-try-fallbacks.y-end
css.properties.position-try-fallbacks.y-start
css.properties.position-try
css.properties.position-try.block-end
css.properties.position-try.block-start
css.properties.position-try.bottom
css.properties.position-try.center
css.properties.position-try.end
css.properties.position-try.flip-block
css.properties.position-try.flip-inline
css.properties.position-try.flip-start
css.properties.position-try.flip-x
css.properties.position-try.flip-y
css.properties.position-try.inline-end
css.properties.position-try.inline-start
css.properties.position-try.left
css.properties.position-try.none
css.properties.position-try.right
css.properties.position-try.self-block-end
css.properties.position-try.self-block-start
css.properties.position-try.self-end
css.properties.position-try.self-inline-end
css.properties.position-try.self-inline-start
css.properties.position-try.self-start
css.properties.position-try.self-x-end
css.properties.position-try.self-x-start
css.properties.position-try.self-y-end
css.properties.position-try.self-y-start
css.properties.position-try.span-all
css.properties.position-try.span-block-end
css.properties.position-try.span-block-start
css.properties.position-try.span-bottom
css.properties.position-try.span-end
css.properties.position-try.span-inline-end
css.properties.position-try.span-inline-start
css.properties.position-try.span-left
css.properties.position-try.span-right
css.properties.position-try.span-self-block-end
css.properties.position-try.span-self-block-start
css.properties.position-try.span-self-end
css.properties.position-try.span-self-inline-end
css.properties.position-try.span-self-inline-start
css.properties.position-try.span-self-start
css.properties.position-try.span-self-x-end
css.properties.position-try.span-self-x-start
css.properties.position-try.span-self-y-end
css.properties.position-try.span-self-y-start
css.properties.position-try.span-start
css.properties.position-try.span-top
css.properties.position-try.span-x-end
css.properties.position-try.span-x-start
css.properties.position-try.span-y-end
css.properties.position-try.span-y-start
css.properties.position-try.start
css.properties.position-try.top
css.properties.position-try.x-end
css.properties.position-try.x-start
css.properties.position-try.y-end
css.properties.position-try.y-start
css.properties.position-visibility
css.properties.position-visibility.always
css.properties.position-visibility.anchors-valid
css.properties.position-visibility.anchors-visible
css.properties.position-visibility.no-overflow
css.properties.right.anchor
css.properties.right.anchor-size
css.properties.top.anchor
css.properties.top.anchor-size
css.properties.width.anchor-size
css.types.length.rcap
css.types.length.rch
css.types.length.rex
css.types.length.ric

Updated in other PRs:

webdriver.bidi.emulation.setLocaleOverride.locale_parameter.sets_accept-language_header
webdriver.bidi.input.fileDialogOpened_event
webdriver.bidi.input.fileDialogOpened_event.context_parameter
webdriver.bidi.input.fileDialogOpened_event.element_parameter
webdriver.bidi.input.fileDialogOpened_event.multiple_parameter

See also mdn/mdn#776 and https://www.mozilla.org/en-US/firefox/147.0beta/releasenotes/

github-actions · 2025-12-09T15:04:00Z

Tip: Review these changes grouped by change (recommended for most PRs), or grouped by feature (for large PRs).

caugner

LGTM.

Note: Not all features are mentioned in the release notes.

Feature	Ref
api.CSSPositionTryDescriptors	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=CSS%20anchor%20positioning
api.CSSPositionTryDescriptors.*	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=CSS%20anchor%20positioning
api.CSSPositionTryRule	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=CSS%20anchor%20positioning
api.CSSPositionTryRule.name	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=CSS%20anchor%20positioning
api.CSSPositionTryRule.style	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=CSS%20anchor%20positioning
api.Document.activeViewTransition	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=Document%2EactiveViewTransition
api.Element.setHTML	https://bugzilla.mozilla.org/show_bug.cgi?id=1995692
api.NavigateEvent	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=Navigation%20API
api.NavigateEvent.*	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=Navigation%20API
api.Navigation	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=Navigation%20API
api.Navigation.*	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=Navigation%20API
api.NavigationActivation	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=Navigation%20API
api.NavigationActivation.*	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=Navigation%20API
api.NavigationCurrentEntryChangeEvent	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=Navigation%20API
api.NavigationCurrentEntryChangeEvent.*	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=Navigation%20API
api.NavigationDestination	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=Navigation%20API
api.NavigationDestination.*	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=Navigation%20API
api.NavigationHistoryEntry	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=Navigation%20API
api.NavigationHistoryEntry.*	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=Navigation%20API
api.NavigationPrecommitController	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=Navigation%20API
api.NavigationTransition	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=Navigation%20API
api.NavigationTransition.*	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=Navigation%20API
api.Sanitizer	https://bugzilla.mozilla.org/show_bug.cgi?id=1995692
api.Sanitizer.*	https://bugzilla.mozilla.org/show_bug.cgi?id=1995692
api.TrustedHTML	https://bugzilla.mozilla.org/show_bug.cgi?id=1994690
api.TrustedScript	https://bugzilla.mozilla.org/show_bug.cgi?id=1994690
api.TrustedScriptURL	https://bugzilla.mozilla.org/show_bug.cgi?id=1994690
api.TrustedTypePolicy	https://bugzilla.mozilla.org/show_bug.cgi?id=1994690
api.TrustedTypePolicyFactory	https://bugzilla.mozilla.org/show_bug.cgi?id=1994690
api.ViewTransition.types	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=%3Aactive%2Dview%2Dtransition%2Dtype
api.ViewTransitionTypeSet	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=%3Aactive%2Dview%2Dtransition%2Dtype
api.Window.navigation	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=Navigation%20API
api.trustedTypes	https://bugzilla.mozilla.org/show_bug.cgi?id=1994690
css.properties.align-items.anchor-center	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=CSS%20anchor%20positioning
css.properties.align-self.anchor-center	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=CSS%20anchor%20positioning
css.properties.anchor-name	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=CSS%20anchor%20positioning
css.properties.anchor-name.none	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=CSS%20anchor%20positioning
css.properties.anchor-scope	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=CSS%20anchor%20positioning
css.properties.anchor-scope.all	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=CSS%20anchor%20positioning
css.properties.anchor-scope.none	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=CSS%20anchor%20positioning
css.properties.block-size.anchor-size	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=CSS%20anchor%20positioning
css.properties.bottom.anchor	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=CSS%20anchor%20positioning
css.properties.bottom.anchor-size	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=CSS%20anchor%20positioning
css.properties.height.anchor-size	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=CSS%20anchor%20positioning
css.properties.inline-size.anchor-size	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=CSS%20anchor%20positioning
css.properties.inset*.anchor	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=CSS%20anchor%20positioning
css.properties.inset*.anchor-size	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=CSS%20anchor%20positioning
css.properties.justify-items.anchor-center	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=CSS%20anchor%20positioning
css.properties.justify-self.anchor-center	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=CSS%20anchor%20positioning
css.properties.left.anchor	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=CSS%20anchor%20positioning
css.properties.left.anchor-size	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=CSS%20anchor%20positioning
css.properties.margin-*.anchor-size	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=CSS%20anchor%20positioning
css.properties.max-*.anchor-size	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=CSS%20anchor%20positioning
css.properties.min-*.anchor-size	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=CSS%20anchor%20positioning
css.properties.place-items.anchor-center	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=CSS%20anchor%20positioning
css.properties.place-self.anchor-center	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=CSS%20anchor%20positioning
css.properties.position-anchor	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=CSS%20anchor%20positioning
css.properties.position-anchor.auto	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=CSS%20anchor%20positioning
css.properties.position-area	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=CSS%20anchor%20positioning
css.properties.position-try-fallbacks	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=CSS%20anchor%20positioning
css.properties.position-try	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=CSS%20anchor%20positioning
css.properties.position-visibility	https://bugzilla.mozilla.org/show_bug.cgi?id=1909341
css.properties.position-visibility.always	https://bugzilla.mozilla.org/show_bug.cgi?id=1909341
css.properties.position-visibility.anchors-valid	https://bugzilla.mozilla.org/show_bug.cgi?id=1909341
css.properties.position-visibility.anchors-visible	https://bugzilla.mozilla.org/show_bug.cgi?id=1909341
css.properties.position-visibility.no-overflow	https://bugzilla.mozilla.org/show_bug.cgi?id=1909341
css.properties.right.anchor	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=CSS%20anchor%20positioning
css.properties.right.anchor-size	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=CSS%20anchor%20positioning
css.properties.top.anchor	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=CSS%20anchor%20positioning
css.properties.top.anchor-size	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=CSS%20anchor%20positioning
css.properties.width.anchor-size	https://www.firefox.com/en-US/firefox/147.0beta/releasenotes/#:~:text=CSS%20anchor%20positioning
css.types.length.rcap	https://bugzilla.mozilla.org/show_bug.cgi?id=1879175
css.types.length.rch	https://bugzilla.mozilla.org/show_bug.cgi?id=1879175
css.types.length.rex	https://bugzilla.mozilla.org/show_bug.cgi?id=1879175
css.types.length.ric	https://bugzilla.mozilla.org/show_bug.cgi?id=1879175

hamishwillee · 2025-12-09T21:37:11Z

@caugner Are you sure about Trusted Types - this isn't in our release plan because https://bugzilla.mozilla.org/show_bug.cgi?id=1994690#c4 doesn't indicate it should ship. I'm querying.

fred-wang · 2025-12-10T06:24:10Z

TT was only for "early beta", it's not yet shipping in release. And I understand it's only enabled the first weeks of beta.

caugner · 2025-12-10T09:34:38Z

@hamishwillee @fred-wang Are you aware of a way to disable "early beta" features programmatically? In either case, it seems like we need a collector run for the stable release as well, assuming features can be (a) disabled during beta, and (b) "uplifted" from "early beta". (cc @Elchi3)

Elchi3 · 2025-12-10T09:48:29Z

Sorry about the trouble, let's revert the TT changes then.

btw, this came up for Chrome, too: openwebdocs/mdn-bcd-collector#951 (comment).
For Firefox, I'm unfortunately not aware of any command that makes the beta behave like a stable Firefox.

fred-wang · 2025-12-10T10:15:27Z

"early beta" is a cpp define, I don't think it can be switched programmatically: https://wiki.mozilla.org/Platform/Channel-specific_build_defines#EARLY_BETA_OR_EARLIER

Elchi3 · 2025-12-10T10:22:58Z

Should we ask if Firefox would be open to implement such a switch?

hamishwillee · 2025-12-12T00:15:35Z

Should we ask if Firefox would be open to implement such a switch?

@Elchi3 I mentioned this need in passing. Developer suggests we add an bugzilla issue to request the switch. I assume that BCD team are best people to do that.

Updates for Firefox 147 beta

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github-actions bot added data:api Compat data for Web APIs. https://developer.mozilla.org/docs/Web/API data:css Compat data for CSS features. https://developer.mozilla.org/docs/Web/CSS size:xl [PR only] >1000 LoC changed labels Dec 9, 2025

This was referenced Dec 9, 2025

Firefox 147 support for activeViewTransition property #28597

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FF147: Navigation API supported #28605

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Fx147 support for view transition types #28613

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[PROJECT] Firefox 147 mdn/mdn#776

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caugner approved these changes Dec 9, 2025

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caugner merged commit 39d27db into mdn:main Dec 9, 2025
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Elchi3 deleted the firefox-147-beta branch December 9, 2025 17:14

mdn-bot mentioned this pull request Dec 9, 2025

Release v7.2.0 #28610

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hamishwillee mentioned this pull request Dec 9, 2025

[Web API] Ship Navigation API mdn/content#42254

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Elchi3 mentioned this pull request Dec 10, 2025

Firefox 147 doesn't yet ship Trusted Types #28630

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Firefox 147 ships CSS Anchor Positioning #28649

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[CSS] Add initial support for the 'anchor-center' value mdn/content#42349

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This was referenced Dec 19, 2025

42252 add new relative units mdn/content#42469

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42252 add new relative units ff release mdn/content#42470

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[CSS] Add new relative units RCH, REX, RCAP, and RIC mdn/content#42252

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jakearchibald mentioned this pull request Jan 8, 2026

Sanitizer isn't landing until Firefox 148 #28774

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Elchi3 mentioned this pull request Jan 14, 2026

Firefox 147 ships Navigation events #28822

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Updates for Firefox 147 beta#28624

Updates for Firefox 147 beta#28624
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