The 15 best open-source UI components libraries in 2026, ranked by our maintenance-health metric plus real adoption (stars and weekly downloads) and security signals. Right now bootstrap leads the field with a 100/100 health score. Each links to a full analysis with install commands, license, and alternatives.
Bootstrap is a CSS-first front-end framework that bundles a responsive grid, prebuilt UI components, and utility classes, plus a small set of JavaScript widgets (built on Popper), letting developers assemble styled, mobile-friendly interfaces without writing CSS from scratch.
ui is an open-source TypeScript project in the ui components space with 116.3k GitHub stars. The repository is actively maintained, with recent commits.
Material UI is a comprehensive React component library implementing Google's Material Design, providing a large set of ready-made, customizable, accessible UI components and a powerful theming/styling system.
Tailwind CSS is a utility-first CSS framework that lets you build custom designs directly in your markup by composing low-level utility classes instead of writing custom CSS. It generates only the styles you use via a build step, keeping output small.
Storybook is a frontend workshop for developing, testing, and documenting UI components in isolation. It renders components outside your app in a dedicated browser environment and supports React, Vue, Angular, Svelte, Web Components, and many other frameworks through a pluggable addon ecosystem.
A massive, community-curated awesome-list of free and freemium design assets and tools for developers — covering UI graphics, fonts, color tools, icons, stock media, CSS/JS libraries, design systems, and AI design tools. It's a categorized link directory rather than a software library.
Ionic Framework is a cross-platform UI toolkit built on Web Components for building native-quality mobile apps and Progressive Web Apps from a single codebase. It ships a large library of pre-styled, accessible UI components with first-class bindings for Angular, React, and Vue.
Bulma is a free, open-source CSS framework based on Flexbox that provides ready-to-use, responsive UI components and a grid system without requiring any JavaScript. It's distributed as a single CSS file or as customizable Sass source.
uni-app is an open-source Objective-C project in the ui components space with 41.5k GitHub stars. The repository is actively maintained, with recent commits.
daisyUI is a component library for Tailwind CSS that adds semantic class names (like btn, card, modal) and themeable components on top of Tailwind's utility classes, reducing markup verbosity while staying framework-agnostic.
Vuetify is a comprehensive Vue component library implementing Material Design, offering a large catalog of ready-made, accessible UI components and a theming/layout system for building Vue 3 applications.
xyflow is a monorepo of open-source libraries (React Flow and Svelte Flow) for building interactive node-based UIs such as flowcharts, diagrams, and workflow editors. It provides draggable nodes, connectable edges, and built-in components like minimaps, controls, and backgrounds, all heavily customizable.
TanStack Table is a headless, framework-agnostic datagrid library that supplies table logic—sorting, filtering, grouping, aggregation, pagination, and row selection—while leaving all markup and styling to the developer. It ships adapters for React, Vue, Solid, Svelte, Angular, and Lit.
Quasar is a Vue.js-based framework that bundles a rich Material Design component library with build tooling, letting developers ship SPAs, SSR apps, PWAs, mobile (Cordova/Capacitor), Electron desktop apps, and browser extensions from one codebase.
MDB UI Kit is a Material Design component library built on top of Bootstrap 5, offering 700+ UI components, form controls, and templates implemented in SCSS and plain (vanilla) JavaScript. It extends Bootstrap's styling with Material Design aesthetics while remaining framework-agnostic.