Best CSS frameworks on npm
Frameworks that give a project its base styles, components or utility classes. tailwindcss leads with about 173M real installs a week, followed by bootstrap with about 8.1M.
| package | real installs / week | npm / week | noise | last release | confidence |
|---|---|---|---|---|---|
| 1. tailwindcssA utility-first CSS framework for rapidly building custom user interfaces. | 173M | 172,937,919 | under 1% | Nov 2026 | high |
| 2. bootstrapThe most popular front-end framework for developing responsive, mobile first projects on the web. | 8.1M | 8,104,775 | under 1% | Aug 2025 | high |
| 3. unocssThe instant on-demand Atomic CSS engine. | 735K–737K | 737,151 | under 1% | Oct 2026 | high |
| 4. bulmaModern CSS framework based on Flexbox | 457K–458K | 457,992 | under 1% | Apr 2025 | high |
| 5. foundation-sitesThe most advanced responsive front-end framework in the world. | 125K | 125,486 | under 1% | Sep 2024 | high |
| 6. @picocss/picoMinimal CSS Framework for semantic HTML | 68.8K–69.4K | 69,374 | under 1% | Mar 2025 | high |
Ranked by real installs. That measures use, not quality: read the notes below before choosing. Mirror spikes and crawlers removed. CI and dependency installs still count, so this is not a head count. Noise: the share of npm's count that mirror spikes and crawlers account for. What remains still includes CI and dependency installs. Rows are refreshed in rotation, the oldest here on Nov 6, 2026.
How do they differ?
Tailwind CSS and UnoCSS are built around utility classes. Bootstrap and Foundation ship ready-made components. Bulma is CSS only, with no JavaScript. Pico styles plain HTML with few or no classes.