HTML Sandbox

Runs in your browser

Write HTML, CSS and JS and see it render live, isolated from the site.

HTML auto-run

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <style>
    body { font-family: system-ui, sans-serif; padding: 24px; color: #211E2B; }
    h1   { color: #0FA97C; margin: 0 0 8px; }
    .box { padding: 14px; border-radius: 10px; background: #F1F0EC; }
  </style>
</head>
<body>
  <h1>Hello from the sandbox</h1>
  <div class="box">Edit the code on the left — the preview updates as you type.</div>
  <p id="t"></p>
  <script>
    document.getElementById('t').textContent =
      'JavaScript runs too: ' + new Date().toLocaleTimeString();
  </script>
</body>
</html>

Preview JavaScript

Your code runs in your browser only and is never sent anywhere. The preview is isolated in an iframe sandbox with no allow-same-origin, so it can run JavaScript freely but cannot touch this site's cookies, localStorage, or anything else. Untick the JavaScript box to render the markup without scripts. Press Esc to leave fullscreen.