# Astro astro@6.0.4 — Release & Upgrade Intelligence
- **Product:** Astro (https://astro.build)
- **Version:** astro@6.0.4
- **Released:** Mar 12, 2026
- **Impact Score:** 5/10
- **Breaking Changes:** Not verified
- **Canonical Analysis:** https://changelogs.us/astro/updates/astro-6.0.4/

## Executive Summary (TL;DR)
Astro astro@6.0.4. Source highlight: Prebundle `astro/toolbar` in dev when custom dev toolbar apps are registered, preventing re-optimization reloads that can hide or break the toolbar.

## Bug Fixes
- Prebundle `astro/toolbar` in dev when custom dev toolbar apps are registered, preventing re-optimization reloads that can hide or break the toolbar.
- Fixes `redirectToDefaultLocale` producing a protocol-relative URL (`//locale`) instead of an absolute path (`/locale`) when `base` is `'/'`.
- Fixes server islands (`server:defer`) not working when only used in prerendered pages with `output: 'server'`.
- Fix a dev server bug where newly created pages could miss layout-imported CSS until restart.
- Fixes a warning when using `prefetchAll`
- Fixes a bug where a directory at the project root sharing the same name as a page route would cause the dev server to return a 404 instead of serving the page.

## Upgrade Command
```bash
npm install --save-exact astro@6.0.4
```