StacckApp

HTML/CSS/JS Playground (Live Preview)

A free in-browser playground for HTML, CSS, and JavaScript. Edit in three CodeMirror panels with a sandboxed live preview. Download as a single .html file. 100% client-side.

Edits auto-save in your browser. Nothing is uploaded.

About this playground

Three CodeMirror editors plus a sandboxed preview iframe. Your code runs locally in the iframe — nothing is uploaded to any server. Your edits persist in your browser via localStorage per the keys stacckapp-playground-html, -css, -js.

About HTML/CSS/JS Playground (Live Preview)

The HTML/CSS/JS Playground gives you three CodeMirror editors for markup, styles, and scripts. Type into any panel and the sandboxed preview pane re-renders so you can see the result. When you are happy with it, use the download button to save everything as a single self-contained .html file.

Frequently asked questions

Is my code saved on a server?
The editing and preview happen client-side in your browser; code is processed by the page itself rather than stored in an account.
Can I export my work?
Yes. The download button produces one .html file containing the HTML, CSS, and JavaScript together, which you can open or share.
Does the preview run JavaScript?
Yes. The preview is a sandboxed iframe that executes your JavaScript so you can test interactive behavior.