Component Coverage Comparison: Rad UI, Radix UI, Base UI, Ark UI, Headless UI

Executive Summary

This document is a straight, side-by-side look at component coverage across modern headless and semi-headless UI libraries:

Rad UI, Radix UI, Base UI, Ark UI, and Headless UI.

This is not a “best library” ranking. Coverage is not quality.
The goal is simple:

Compare which building blocks exist across the ecosystem
Identify components commonly expected in production UIs
Make Rad UI’s roadmap and priorities transparent

This comparison focuses purely on component availability, not API design, accessibility depth, performance, styling strategy, or composability philosophy.

High-level observations

Rad UI surface area: 54 components total (33 released, 21 in development)
Most common missing building blocks: 6 components repeatedly show up across other libraries but are not yet in Rad UI
Differentiation: Rad UI includes an explicit typography and layout layer that most peers avoid
Coverage positioning: broader surface area than Radix UI and Headless UI, comparable breadth to Ark UI

Current Rad UI Component Inventory

Total Components: 54

Officially Released: 33

In Codebase / In Progress: 21

Accordion
AlertDialog
AspectRatio
Avatar
AvatarGroup
Badge
BlockQuote
Button
Callout
Card
Checkbox
CheckboxCards
CheckboxGroup
Code
Collapsible
ContextMenu
DataList
Dialog
Disclosure
DropdownMenu
Em
Heading
HoverCard
Kbd
Link
Menubar
Minimap
NavigationMenu
NumberField
Progress
Quote
Radio
RadioCards
RadioGroup
ScrollArea
Select
Separator
Skeleton
Slider
Splitter
Steps
Strong
Switch
Table
TabNav
Tabs
Text
TextArea
Theme
Toggle
ToggleGroup
Tooltip
Tree
VisuallyHidden

Component Coverage Matrix

Component	Rad UI	Radix UI	Base UI	Ark UI	Headless UI	Priority
Layout & Structure
Accordion	✅	✅	✅	✅	❌	–
AspectRatio	✅	✅	❌	❌	❌	–
Separator	✅	✅	✅	❌	❌	–
Splitter	✅	❌	❌	✅	❌	–
Steps	✅	❌	❌	✅	❌	–
Navigation
Breadcrumb	❌	❌	✅	✅	❌	🔴 High
NavigationMenu	✅	✅	❌	❌	❌	–
Menubar	✅	✅	❌	❌	❌	–
TabNav	✅	❌	❌	❌	❌	–
Tabs	✅	✅	✅	✅	✅	–
Overlays & Dialogs
AlertDialog	✅	✅	✅	✅	❌	–
Dialog	✅	✅	✅	✅	✅	–
Popover	❌	✅	✅	✅	✅	🔴 High
Tooltip	✅	✅	✅	✅	❌	–
HoverCard	✅	✅	❌	✅	❌	–
BottomSheet	❌	❌	❌	✅	❌	🟡 Medium
FloatingPanel	❌	❌	❌	✅	❌	🟡 Medium
Forms & Inputs
Button	✅	✅	✅	✅	❌	–
Checkbox	✅	✅	✅	✅	❌	–
CheckboxGroup	✅	❌	✅	✅	❌	–
CheckboxCards	✅	❌	❌	❌	❌	–
Radio	✅	✅	✅	✅	❌	–
RadioGroup	✅	✅	✅	✅	✅	–
RadioCards	✅	❌	❌	❌	❌	–
Switch	✅	✅	✅	✅	✅	–
Toggle	✅	✅	✅	✅	❌	–
ToggleGroup	✅	✅	✅	✅	❌	–
TextArea	✅	❌	✅	✅	❌	–
NumberField	✅	❌	✅	✅	❌	–
Select	✅	✅	✅	✅	❌	–
Combobox	❌	❌	✅	✅	✅	🔴 High
DatePicker	❌	❌	✅	✅	❌	🔴 High
TimePicker	❌	❌	✅	✅	❌	🟡 Medium
Data Display
Avatar	✅	✅	✅	✅	❌	–
AvatarGroup	✅	❌	❌	❌	❌	–
Badge	✅	❌	✅	❌	❌	–
Card	✅	❌	✅	❌	❌	–
Table	✅	❌	✅	✅	❌	–
Skeleton	✅	❌	❌	❌	❌	–
Feedback & Notifications
Toast	❌	✅	✅	✅	❌	🔴 High
Callout	✅	❌	❌	❌	❌	–
Typography
Heading	✅	❌	❌	❌	❌	–
Text	✅	❌	❌	❌	❌	–
Code	✅	❌	❌	❌	❌	–
Kbd	✅	❌	❌	❌	❌	–
Em	✅	❌	❌	❌	❌	–
Strong	✅	❌	❌	❌	❌	–
BlockQuote	✅	❌	❌	❌	❌	–
Quote	✅	❌	❌	❌	❌	–
Link	✅	❌	❌	❌	❌	–

Commonly Expected Components Not Yet in Rad UI

These components appear across multiple libraries and are frequently expected in production apps.

🔴 High Priority

Popover
Present in Radix UI, Base UI, Ark UI, Headless UI
Combobox
Present in Base UI, Ark UI, Headless UI
DatePicker
Present in Base UI, Ark UI
Toast
Present in Radix UI, Base UI, Ark UI
Pagination
Present in Base UI, Ark UI
Breadcrumb
Present in Base UI, Ark UI

This list is not “missing features shame”. It is the practical roadmap required to meet the baseline expectations of modern product UIs.

Coverage Summary by Category

Category	Rad UI	Radix UI	Base UI	Ark UI	Headless UI
Layout & Structure	5	2	1	2	0
Navigation	4	2	1	2	1
Overlays & Dialogs	5	4	3	6	2
Forms & Inputs	18	7	15	20	3
Data Display	8	1	3	6	0
Menus	3	2	2	3	2
Feedback	1	1	1	1	0
Typography	9	0	0	0	0
Utilities	7	3	0	10	1
Total	54	22	25	50	9

Where Rad UI Differentiates

Rad UI intentionally includes layers that most headless libraries avoid.

Typography layer
A structured, reusable typography system rather than leaving every team to reinvent it.
Extended form patterns
Components like CheckboxCards and RadioCards reduce app-level glue code for real product patterns.
Layout primitives
Splitter, Steps, and Minimap support product UIs and internal tools without requiring third-party add-ons.
Theme abstraction
Rad UI includes a dedicated Theme component rather than treating theming as a purely external setup.

This is not “more components for the sake of it”.
It is coverage aimed at real world UI work.

Opportunities for Expansion

The most meaningful additions are well-known UI baselines:

Add commonly expected overlays: Popover, Toast
Expand date and time inputs: DatePicker, TimePicker
Improve navigation primitives: Pagination, Breadcrumb
Introduce optional animation and transition primitives (opt-in, not opinionated)

Contributing

Want to help expand component coverage? Amazing. Pick a high-impact component and ship it.

High Priority Components

Popover
Overlay content positioned relative to a trigger
Combobox
Autocomplete input with suggestions
DatePicker
Date selection with calendar UI
Toast
Notification system for feedback and status
Breadcrumb
Hierarchical navigation path
Pagination
Navigation for paginated content

Last updated: December 2025
Document version: 1.0