# Tailwind CSS v4.2.3 — Release & Upgrade Intelligence
- **Product:** Tailwind CSS (https://tailwindcss.com)
- **Version:** v4.2.3
- **Released:** Apr 20, 2026
- **Impact Score:** 5/10
- **Breaking Changes:** Not verified
- **Canonical Analysis:** https://changelogs.us/tailwind/updates/v4.2.3/

## Executive Summary (TL;DR)
Tailwind CSS v4.2.3. Source highlight: Canonicalization: improve canonicalizations for `tracking-*` utilities by preferring non-negative utilities (e.g. `-tracking-tighter` → `tracking-wider`) (#19827)

## Bug Fixes
- Canonicalization: improve canonicalizations for `tracking-*` utilities by preferring non-negative utilities (e.g. `-tracking-tighter` → `tracking-wider`) (#19827)
- Fix crash due to invalid characters in candidate (exceeding valid unicode code point range) (#19829)
- Ensure query params in imports are considered unique resources when using `@tailwindcss/webpack` (#19723)
- Canonicalization: collapse arbitrary values into shorthand utilities (e.g. `px-[1.2rem] py-[1.2rem]` → `p-[1.2rem]`) (#19837)
- Canonicalization: collapse `border-{t,b}-*` into `border-y-*`, `border-{l,r}-*` into `border-x-*`, and `border-{t,r,b,l}-*` into `border-*` (#19842)
- Canonicalization: collapse `scroll-m{t,b}-*` into `scroll-my-*`, `scroll-m{l,r}-*` into `scroll-mx-*`, and `scroll-m{t,r,b,l}-*` into `scroll-m-*` (#19842)

## Upgrade Command
```bash
npm install --save-exact tailwindcss@4.2.3
```