Web projects and preview

A Web project runs in your own browser rather than a sandbox. What the preview renders, why there is no Run button, and what that means for what you can build.

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If your HTML page is blank, or there is no Run button on your web project, this page explains both. A Web project is HTML, CSS and JavaScript, and it does not go to a sandbox. It renders in your own browser, live, in the preview pane.

There is no Run button#

There is nothing to press because there is nothing to send. The preview updates from your files - the preview is the run.

The preview renders the entry file#

It renders the project's stored entry file and nothing else changes that.

To preview a different page, set it as the entry from the file tree.

What you can build#

Everything a static page can do: your own scripts, your own styles, fetch to public APIs, browser storage.

What you cannot do is anything needing a server - there is no backend, no build step and no package install. A framework that requires bundling before it runs will not run here.

Debugging#

The preview is a real frame in your real browser, so your browser's own developer tools work on it. That is usually a faster read than anything the workspace could show you.

Running your code

How every other kind runs.

Sharing a project

Letting somebody else see it.

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Last checked against the product on . Behaviour changes are listed in the changelog.