BaseUI

component

Library of headless, unstyled React components that provide full control over markup and CSS while delivering strong accessibility defaults and ARIA-compliant behavior.Designed as composable primitives with a slots-based API, components are tree‑shakeable, TypeScript-ready, and work with any styling approach including Tailwind, CSS Modules, CSS-in-JS, or plain CSS.Covers a wide set of UI patterns and primitives such as Accordion, Alert Dialog, Avatar, Checkbox and Checkbox Group, Collapsible, Context Menu, Dialog, Field and Fieldset, Form, Input, Menu and Menubar, Meter, Navigation Menu, Number Field, Popover, Progress, Radio, Scroll Area, Select, Separator, Slider, Switch, Tabs, Toast, Toggle and Toggle Group, Toolbar, Tooltip, plus utilities like Direction Provider and useRender.Popup components use React Portals and recommend creating an isolated stacking context to avoid z-index conflicts, helping overlays always appear above page content. Documentation includes examples for assembling components, composing parts, and integrating with different styling systems.Open-source under the MIT license with active releases, roadmap, and accessibility-focused guidance. Documentation pages can be viewed as Markdown and include LLM-friendly resources for easier code exploration and integration.

Features

• Headless, unstyled React components
• Accessible by default with ARIA-compliant behavior
• Composable, slots-based API
• Tree-shakeable ESM builds
• TypeScript typings
• Works with Tailwind, CSS Modules, CSS-in-JS, or plain CSS
• React Portals for popups and overlays
• Guidance for stacking context isolation to avoid z-index issues
• Controlled and uncontrolled usage patterns
• Broad component coverage (menus, dialogs, popovers, tabs, selects, sliders, etc.)
• SSR-friendly and framework-agnostic
• Open-source MIT license
• Documentation available as Markdown with LLM helpers