How it works
Three steps. No setup, no cost.
- Step 1
Edit a real site
A small café site is waiting: two pages, three components, a layout. Pages are files, components are widgets you can open, and all of it is readable text.
- Step 2
Watch it rebuild in the tab
The site installs and builds inside your browser. Nothing is uploaded and no server is involved. Change a line and the preview catches up.
- Step 3
Drop it live
Download the built site as a zip and drag it onto a free host. You get a live URL without creating an account anywhere.
Where to start
Pick a door.
Agents
Let Claude edit it with you.
With the Claude in Chrome extension, Claude can work in your playground tab. Open the editor, ask for a change in plain words, and watch the files and the preview update as it works. No terminal, nothing to install beyond the extension.
Prefer the command line? Claude Code and Claude Desktop connect too, with one claude mcp add command. The Agent button in the editor has both setups.
Deploy
The download is the whole site.
HTML, CSS and assets, with headers, a 404 page and a Vercel config already inside. It runs on anything that serves files, and every host below has a free plan that fits a site like this.
- Netlify DropFree
- Drag the zip onto the page. Live in seconds, no account to try.
- Cloudflare PagesFree
- Upload the folder. Fast CDN, generous free plan.
- VercelFree
- Unzip and run npx vercel --prod. The config is included.
- GitHub PagesFree
- Push the files and turn on Pages.
- Any web host
- FTP it into public_html. No PHP, no database.
Questions
The things people ask first.
- Where is my site stored?
- In your browser. The build runs in the tab and the project is saved in that browser’s storage. Nothing is uploaded, and there is no account. Clear the browser and it is gone, so export anything you want to keep.
- Can I keep working on it somewhere else?
- Yes. Project → Export gives you the full Astro source as a zip: a normal Astro project you can open in any editor, run with npm run dev, and push to GitHub. Download site gives you the built HTML for hosting.
- Is it really free?
- Yes. There is nothing to sign up for and nothing to pay. The only optional cost is your own Claude subscription, if you want AI to edit the site with you.
- How is this different from astro.build/play or astro.new?
- astro.build/play is Astro’s compiler playground: you paste one .astro file and see what the compiler turns it into. Useful for learning the compiler, not for making a site. astro.new opens starter templates in online code sandboxes like StackBlitz, which are general-purpose editors with a dev server and usually an account. AstroPlayground is a whole site with pages, the real static build running in your tab, a hands-on tour, a component view, share links, and a zip you can drop on a host. No account, nothing to set up.
- How does this relate to PhantomStudio?
- Same people. The playground is the free, open-ended way to try Astro and build simple static sites. PhantomStudio is the full product for client work, with a real dev environment, WordPress as a CMS, git and deploys. You can start here and export your project to it later, or never, both are fine.