This feature has been added to the official vite plugin in Tailwind CSS v4.0.5 but removed in v4.0.6.

Tailwind v4 as been released but the official tailwind vite plugin does not (yet) eliminate dead css.

• Remove unused custom properties in cascade
• Remove unused keyframes
• Print basic logs

npm i vite-plugin-tailwindcss-cleaner

import { defineConfig } from "vite"
import tailwindcss from "@tailwindcss/vite"
import tailwindcssCleaner from "vite-plugin-tailwindcss-cleaner"

export default defineConfig({
	plugins: [
		tailwindcss(),
		tailwindcssCleaner()
	]
})