Is there a simple browser tab/preview extension? (no server needed)

Hi,

I'm working with Svelte (but React or Angular have the same use case) and I simply want a browser preview **inside** VScode that points to the address of Svelte's dev server (or any arbitrary address for that matter).

The extensions that I've found so far spawn a server to preview static HTML files, that's not what I need though.

Switching between VScode and an external browser is too annoying for me.

Is there such an extension out there?