Publishing
Limits and troubleshooting
| File | A single self-contained .html, or a .zip with index.html and its images at the top level. |
|---|---|
| Size | Up to 5 MB, measured after the images are bundled in. A larger file is almost always large images: ask Claude to compress them, or use fewer. |
| Name | Becomes part of the prototype's address, so it must be unique. That name is already taken means another prototype uses it — choose a different one. |
It runs in a sandbox
An uploaded prototype runs apart from the hub. It cannot see your hub session, and browser storage — localStorage, sessionStorage, cookies — is not available to it. Keep its state in memory; the Claude prompt already asks for that.
A blank page, or a feature that silently does nothing? Check whether the prototype saves to browser storage. It works when you open the file on your computer and fails inside the sandbox.