# Tailwind CSS v4.1.15 — Release & Upgrade Intelligence
- **Product:** Tailwind CSS (https://tailwindcss.com)
- **Version:** v4.1.15
- **Released:** Oct 20, 2025
- **Impact Score:** 5/10
- **Breaking Changes:** Not verified
- **Canonical Analysis:** https://changelogs.us/tailwind/updates/v4.1.15/

## Executive Summary (TL;DR)
Tailwind CSS v4.1.15. Source highlight: Fix Safari devtools rendering issue due to `color-mix` fallback (#19069)

## Bug Fixes
- Fix Safari devtools rendering issue due to `color-mix` fallback (#19069)
- Suppress Lightning CSS warnings about `:deep`, `:slotted`, and `:global` (#19094)
- Fix resolving theme keys when starting with the name of another theme key in JS configs and plugins (#19097)
- Allow named groups in combination with `not-*`, `has-*`, and `in-*` (#19100)
- Prevent important utilities from affecting other utilities (#19110)
- Don’t index into strings with the `theme(…)` function (#19111)

## Upgrade Command
```bash
npm install --save-exact tailwindcss@4.1.15
```