Coding studio

Edit a real interface and run it in a restricted preview. Download your creation and keep building.

How this experiment works

Your JavaScript runs in a disposable worker, connected to allowlisted HTML inside an opaque-origin iframe with a restrictive content policy. The five original projects are preserved.

What it does not prove

The sandbox blocks network access and access to this application. Only a documented DOM subset is supported. Unresponsive JavaScript is stopped by a watchdog. This is a learning sandbox, not a general security guarantee.

Try this challenge

Choose the evidence checklist. Add a fourth item and update the count so it remains correct.

Enable JavaScript to run the experiment on your device.