How to change the default port 5000 in Svelte?

The sveltejs/template uses sirv-cli.
You can add --port or -p in your start:dev script in package.json.

Instead of:

"start:dev": "sirv public --single --dev"

Use:

"start:dev": "sirv public --single --dev --port 5555"

You can see more of sirv-cli options:

https://github.com/lukeed/sirv/tree/master/packages/sirv-cli