Getting StartedComponentsDesign TokensThemingTheme SynthesizerFrameworksAccessibilityUtilitiesServer RenderingBrowser SupportContributingChangelogApp ShellAspect GridAuth ShellCenterContainerDashboard GridFloat BarInsetMasonryPage HeaderPage LayoutResizableResponsive SwitcherSectionSettings LayoutSplit PaneStatus BarStickyToolbarAnchor NavBottom NavBreadcrumbBreadcrumb MenuCommand BarDrawerFooterLinkMenubarNavigation MenuPage IndicatorPaginationRailScroll IndicatorScroll SpyScroll To TopSidebarSkip LinkStepper NavTabsTop BarTree ViewAccordionAspect RatioAvatarAvatar GroupCardCarouselCollapsibleColor SwatchCTA BannerDividerEmpty StateFeature CardIconImageImage CompareImage HotspotsInfinite ScrollLightboxMarqueeQR CodeScroll AreaSkeletonSpinnerStackVideoVirtual ListActivity HeatmapAnimated NumberBadgeBar ListChartClockComparisonCountdown TimerData GridDescription ListDiffGaugeJSON TreeKanbanLevel MeterListMeterSparklineStatStepperTagTimelineUptimeValue CardWaveformBlockquoteCode BlockCode GroupGradient TextHighlightKbdKeyboard MapMarkdownNumber FormatProseTerminalTextTime AgoTruncateTypewriterButtonButton GroupCalendarCheckboxChipColor PickerComboboxCopy ButtonDate PickerDate Range PickerField ListFieldsetFile UploadFormHotkeyIcon ButtonImage CropperInline EditInputInput GroupKnobLabelMasked InputMulti SelectNumber InputPassword InputPin InputRadio GroupRange SliderRatingSearchSegmented ControlSelectSignature PadSliderSortable ListSwitch GroupTag InputTextareaTheme ToggleTime PickerToggleTransfer ListTree SelectAlertAnnouncementBannerCommand PaletteConfirmConnection StatusContext MenuConversationDialogDropdown MenuHover CardLoading OverlayNotification PanelPopoverProgressSheetToastTooltip
ARC UIARC Radiant Components
v4.9DocsComponentsTokensSynthesizer
Getting StartedFrameworksServer RenderingDesign TokensThemingTheme SynthesizerTypographyUtilitiesAll ComponentsAccessibilityBrowser SupportChangelogContributingStatsApp ShellAspect GridAuth ShellCenterContainerDashboard GridFloat BarInsetMasonryPage HeaderPage LayoutResizableResponsive SwitcherSectionSettings LayoutSplit PaneStatus BarStickyToolbarAnchor NavBottom NavBreadcrumbBreadcrumb MenuCommand BarDrawerFooterLinkMenubarNavigation MenuPage IndicatorPaginationRailScroll IndicatorScroll SpyScroll To TopSidebarSkip LinkStepper NavTabsTop BarTree ViewAccordionAspect RatioAvatarAvatar GroupCardCarouselCollapsibleColor SwatchCTA BannerDividerEmpty StateFeature CardIconImageImage CompareImage HotspotsInfinite ScrollLightboxMarqueeQR CodeScroll AreaSkeletonSpinnerStackVideoVirtual ListActivity HeatmapAnimated NumberBadgeBar ListChartClockComparisonCountdown TimerData GridDescription ListDiffGaugeJSON TreeKanbanLevel MeterListMeterSparklineStatStepperTagTimelineUptimeValue CardWaveformBlockquoteCode BlockCode GroupGradient TextHighlightKbdKeyboard MapMarkdownNumber FormatProseTerminalTextTime AgoTruncateTypewriterButtonButton GroupCalendarCheckboxChipColor PickerComboboxCopy ButtonDate PickerDate Range PickerField ListFieldsetFile UploadFormHotkeyIcon ButtonImage CropperInline EditInputInput GroupKnobLabelMasked InputMulti SelectNumber InputPassword InputPin InputRadio GroupRange SliderRatingSearchSegmented ControlSelectSignature PadSliderSortable ListSwitch GroupTag InputTextareaTheme ToggleTime PickerToggleTransfer ListTree SelectAlertAnnouncementBannerCommand PaletteConfirmConnection StatusContext MenuConversationDialogDropdown MenuHover CardLoading OverlayNotification PanelPopoverProgressSheetToastTooltip

Browser Support

ARC UI targets modern evergreen browsers. All components use native Web Components APIs (Custom Elements v1 and Shadow DOM v1).

Overview

ARC UI is built on Lit 3 and ships as ESM-only (type: "module"). No ES5 or legacy module builds are provided.

Supported Browsers

Chrome / Edge
90+
Full support including all CSS features
Firefox
100+
Full support
Safari / iOS Safari
15.4+
Full support (Shadow DOM, Custom Elements, Constructable Stylesheets)
Samsung Internet
15+
Full support (Chromium-based)
Internet Explorer is not supported. Web Components APIs are not available in IE11 and no polyfill is provided.

Web Components APIs

APIChromeFirefoxSafariNotes
Custom Elements v167+63+10.1+Core component registration
Shadow DOM v153+63+10+Style encapsulation
ES Modules61+60+10.1+Import/export syntax
Constructable Stylesheets73+101+16.4+Used by Lit for style sharing
CSS Custom Properties49+31+9.1+Design token system
IntersectionObserver51+55+12.1+Infinite scroll, scroll spy
Clipboard API66+63+13.1+Copy button (code blocks)
@media (scripting)120+113+17+Gates the pre-upgrade hide in base.css; degrades safely

The scripting media query is the one entry newer than the baseline, and not a requirement. It gates the rule that hides components until they upgrade; where unsupported, the query doesn't match and the hide switches off: older browsers get a brief flash of unstyled content, never hidden content. SeeWithout JavaScript.

Polyfills

Evergreen browsers need no polyfills. For older browsers,@webcomponents/webcomponentsjsprovides Custom Elements and Shadow DOM. Load it before any ARC UI imports:

The polyfill costs ~15 KB (gzipped) and may degrade performance. Prefer targeting evergreen browsers.

Node.js

The build tooling and development server require Node.js 24+ (LTS) and pnpm 10+. These are enforced via the engines field in the root package.json.

See Also

ARC UI

Components that glow.One Lit source, seven native targets.

Docs

Project

Arclight

© 2026 Arclight Digital, LLC. All rights reserved.

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