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Deep Dive

Tailwind CSS v4: What's New and How to Migrate

A new engine, CSS-first configuration, and automatic content detection. Everything you need to know about the Tailwind v4 upgrade.

Leanne ThuongDec 16, 202511 min read

Tailwind CSS v4 is a ground-up rewrite with a new engine called Oxide. Here's what changed.

CSS-First Configuration

No more tailwind.config.js. Configure everything in CSS using @theme directives.

Automatic Content Detection

Tailwind v4 automatically finds your template files. No more configuring content paths.

Performance

The new Oxide engine is up to 10x faster for full builds and 100x faster for incremental builds.

New Features

  • Container queries built in
  • 3D transforms
  • Field sizing utilities
  • Color mixing functions
  • Migration

    The official migration tool handles most changes automatically. Manual fixes are needed for custom plugins.