Tailwind CSS v4 Has a Free Lightning-Fast Engine That Changes Everything

Tailwind v4 is a complete rewrite with a new engine that is 10x faster , CSS-first configuration, and zero-config detection. What Changed Tailwind v3 Tailwind v4 Config tailwind.config.js CSS @theme directive Build speed Fast 10x faster (Rust engine) Content detection Manual paths Automatic PostCSS Required Optional Install npm + config npm + import Setup (Simplified) npm install tailwindcss @tailwindcss/vite // vite.config.ts import tailwindcss from " @tailwindcss/vite " ; export default { plugins : [ tailwindcss ()], }; /* app.css — that is your entire config */ @import "tailwindcss" ; No tailwind.config.js . No content paths. No PostCSS config. It just works. CSS-First Configuration @import "tailwindcss" ; @theme { --color-primary : #3b82f6 ; --color-secondary : #10b981 ; --font-display : "Cal Sans" , sans-serif ; --breakpoint-3xl : 1920px ; --animate-fade-in : fade-in 0.5s ease-out ; } @keyframes fade-in { from { opacity : 0 ; } to { opacity : 1 ; } } Custom colors, fonts, breakpoi