# Tailwind CSS v4.2.2 — Release & Upgrade Intelligence
- **Product:** Tailwind CSS (https://tailwindcss.com)
- **Version:** v4.2.2
- **Released:** Mar 18, 2026
- **Impact Score:** 5/10
- **Breaking Changes:** Not verified
- **Canonical Analysis:** https://changelogs.us/tailwind/updates/v4.2.2/

## Executive Summary (TL;DR)
Tailwind CSS v4.2.2. Source highlight: Support Vite 8 in `@tailwindcss/vite` (#19790)

## New Features
- Support Vite 8 in `@tailwindcss/vite` (#19790)

## Bug Fixes
- Don't crash when candidates contain prototype properties like `row-constructor` (#19725)
- Canonicalize `calc(var(--spacing)*…)` expressions into `--spacing(…)` (#19769)
- Fix crash in canonicalization step when handling utilities containing `@property` at-rules (e.g. `shadow-sm border`) (#19727)
- Skip full reload for server only modules scanned by client CSS when using `@tailwindcss/vite` (#19745)
- Improve canonicalization for bare values exceeding default spacing scale suggestions (e.g. `w-1234 h-1234` → `size-1234`) (#19809)
- Fix canonicalization resulting in empty list (e.g. `w-5 h-5 size-5` → `''` instead of `size-5`) (#19812)

## Upgrade Command
```bash
npm install --save-exact tailwindcss@4.2.2
```