Icon

1. 01Responsiveness — The flexibility in detail of the icons at varying sizes
2. 02Visual style consistency — All icons share the same stroke weight, corner radius, and optical sizing approach
3. 03Color — Black and white, flat colors or gradients
4. 04Naming — Name an icon by what it literally is so it can be used flexibly

Checks from checklist.design, MIT.

• Astryx · Meta's open-source React + StyleX design system, 150+ components and 42 templatesS
• Chakra UI · 114 accessible React components with a token-driven styling systemS
• The Component Gallery · 60 UI components cross-referenced against 95 real design systemsS
• Heroicons · 324 MIT SVG icons in four sizes, from the Tailwind CSS teamS
• Iconify · 236 icon sets and 333,975 icons behind one syntax and one free public APIS
• Lucide · 1,768 ISC-licensed stroke icons; the shadcn/ui default setS
• Lucide Animated · 467 MIT Lucide icons that animate on hover, with a markdown page for every icon and a skill file written for an agentS
• Mantine · 150+ styled React components, 70+ hooks, CSS modules, no runtime CSS-in-JSS
• MUI · React component suite: Material UI, MUI X data grid, charts and date pickersS
• Phosphor Icons · 1,512 MIT icons in six weights, from Thin to DuotoneS
• Radix UI · Unstyled accessible React primitives, plus Themes, Colors and IconsS
• React Bits · 234 copy-paste animated React components: text effects, cursors, WebGL backgroundsS
• remocn · 282 Remotion components for product-demo video, installed by the shadcn CLIS
• ReUI · 1,052 free shadcn components, 502 pro blocks, 10 templates, hosted MCPS
• Simple Icons · 3,453 CC0 brand logos with official hex colours and a free colour-aware CDNS
• Untitled UI · Figma UI kit plus React Aria + Tailwind v4 component library with an MCP serverS
• Ant Design · 73-component React library and design language for enterprise back-office appsA
• Atlassian Design System · Atlaskit: 59 Apache-2.0 React components behind Jira, Confluence and BitbucketA
• Boxicons · MIT-licensed icon set, ~3,768 icons in outline, solid and brand stylesA
• Chánh Đại Components · 96-item shadcn registry of pixel-perfect portfolio and marketing componentsA
• Design System Checklist · 232-item open-source checklist for design language, foundations and componentsA
• Design Systems Surf · Database of ~90 public design systems, cross-cut by component and by foundation topicA
• Fluent 2 · Microsoft's design system: 47 web components plus Windows, iOS and Android kitsA
• Font Awesome · 2,883 free icons plus 609 brand marks; the full library is a paid subscriptionA
• gluestack-ui · CLI-installed React Native component library built on NativeWind and Tailwind v4A
• Heroicons Animated · 316 Heroicons rebuilt as Motion-animated React componentsA
• Iconer · 36 open-source icon libraries, 33,271 icons, searchable in one placeA
• Iconoir · 1,671 MIT-licensed SVG icons on a 24px grid, with React, Vue and Flutter packagesA
• interior.dev · 54 MIT micro-interaction components for React, installable as a shadcn registryA
• Irasutoya · 25,415 free Japanese kawaii illustrations, 239 categories, public Blogger JSON feedA
• Its Hover · 263 animated React icons installed one at a time via the shadcn CLIA
• Magic UI · 150+ animated shadcn-compatible React components for landing pagesA
• MingCute Icons · 1,663 icons in regular and filled, shipped as 10 framework packagesA
• Open UI · W3C Community Group research and specs for native, styleable HTML controlsA
• Osmo · Paid vault of 231 GSAP/Webflow interaction recipes plus a 100-button packA
• Radix Icons · 318 crisp 15x15 icons, MIT, one React component eachA
• Remix Icon · 3,231 neutral 24x24 system icons in Line and Fill, under a custom non-OSI licenceA
• shadcn-templ · shadcn/ui ported to Go and templ: 52 components, 27 blocks, its own CLIA
• shadcncraft · Paid shadcn/ui registry plus a 1:1 Figma kit, 8 styles across Radix and Base UIA
• Shopify Polaris · Shopify's admin design system, now shipped as framework-agnostic web componentsA
• Streamline · 447,000+ icons in 34 families, plus illustrations, with an API and an MCP serverA
• Subframe · Visual editor that emits React + Tailwind + Radix code, with an MCP serverA
• SVGL · 665 optimized brand logos as SVG, with a free JSON APIA
• Tabler Icons · 6,184 MIT icons on a 24x24 grid, outline and filledA
• Tamagui · Universal React styling engine, optimizing compiler and ~48 components for web and nativeA
• unlumen UI · Freemium shadcn registry of Motion-driven React componentsA
• Watermelon UI Dashboards · Nine full React admin dashboards installed through the shadcn CLI from a public registryA
• Amicons · 760 icons in 3,040 variants on a 24px grid, Figma and SVG, one-time priceB
• DrawKit · 100+ hand-drawn 2D/3D illustration, icon and Lottie packs; ~40 free, rest behind ProB
• Feather Icons · 287 MIT-licensed 24x24 stroke icons, the original minimal-outline setB
• FigComponents · 1,619 copy-paste Figma components, 1,002 of them free, CC BY 4.0B
• Hugeicons · 59,000+ icons across 9 styles; 5,900 free under CC0, rest is paidB
• Hugeicons Animated · 165 hand-animated Hugeicons installed as React source via the shadcn CLIB
• Isocons · Free isometric SVG icon set, three perspectives, CC BY 4.0B
• Lukasz Adam Illustrations · ~120 free CC0 SVG illustration and icon sets, one Gumroad bundle, no attributionB
• morphicons · Six kilobytes of maths that morph any stroke icon into any other, across Lucide, Heroicons and TablerB
• Park UI · 59 styled Ark UI components delivered by CLI, themed with Panda CSSB
• Primer · GitHub's design system: 62 React components, Octicons and design tokensB
• Quiver · Foundation models that generate and vectorise editable SVGB
• shadcncraft Free · 22 shadcncraft registry items that install with the plain shadcn CLI, no licence keyB
• Smallbits · 290+ free pixel icons drawn on a strict 8x8 gridB
• Untitled UI on GitHub · The MIT source repos behind Untitled UI: components, icons, and 3 starter kitsB
• css.gg · 704 icons drawn in pure CSS — but the licence since v2.1.2 forbids commercial useC
• Icons8 · ~1.3M icons in 47 styles, free only under CC BY-ND with a mandatory backlinkC
• SVG Doodles · ~209 abstract doodle SVGs exportable as JSX, Vue, Svelte, Astro or PNGC