Studio Help

Why did my preview not start?

The preview panel shows your app running live in a real sandbox. When the preview is blank or stuck, it usually means the sandbox is still starting, not that your app is broken.

What the messages mean

“Starting preview” or “Preparing your environment”
The sandbox is booting and installing dependencies. This is normal on the first load. Wait 2 to 3 minutes before taking any action.

“Preview unavailable” or the panel stays blank after 3 minutes
The sandbox did not start in time. This is recoverable. See the steps below.

“Preview restarting”
The sandbox briefly went offline and is coming back. Wait about 60 seconds.

What to do if the preview does not load

1. Click the refresh icon inside the preview panel (not your browser's refresh button).
2. If it stays blank, close the project tab and re-open it from your dashboard. Give the preview another 2 minutes.
3. If you changed a package recently, try reverting the change with a follow-up prompt and see whether the preview loads then.
4. If none of the above works, contact support with your project name and a description of what you see.

Your project is safe

A preview that fails to start does not delete or change your project files. All your work is stored separately from the preview sandbox. You will not lose any progress.

Why the first load takes longer

The first time you open a project in a session, the sandbox starts fresh and installs all your app's dependencies. This one-time startup can take 2 to 3 minutes. After that, the preview loads faster because the sandbox is already running.

The preview goes to sleep when you are away

To save resources, the sandbox for your project pauses automatically after a period of inactivity. When you come back, Studio wakes it up when you open the project. The wake process installs dependencies and starts the dev server again, which takes a couple of minutes. The loading overlay shows progress while it wakes. Your project files are never lost when the sandbox sleeps.