---
title: Preview
description: Start a local preview of the site you are building.
order: 3
---

# vibe21-web-preview

Opens a live preview of the site. The server stays out of the way. You watch how changes are applied.

Need Node.js and pnpm. If either is missing, run [vibe21-system-check](/docs/vibe21-system-check) first.

## When to use it

Run it after [vibe21-web-new](/docs/vibe21-web-new), or any time you want to see the current site without touching the stack yourself.

## How to run it

```
/vibe21-web-preview
```

The agent starts `pnpm dev` in the background and reports the URL. It does not open a browser unless you ask.

## What happens

- If `http://localhost:3000` already responds, the skill reuses that server. A second process is not started.
- If `node_modules` is missing, `pnpm install` runs first. The agent does not ask.
- The default URL is `http://localhost:3000`. If Next.js prints another Local URL, that one is used.
- Edits from later skills appear in the same preview.

This is step 04 in the [quick start](/docs). After it is live, you vibe.