What’s running on port 5173 on my Mac?

Check what’s on port 5173

lsof -nP -iTCP:5173 -sTCP:LISTEN

It’s node. Every Vite project looks the same here, so check the folder:

lsof -a -p <PID> -d cwd -Fn | tail -1

Vite drifts upward when its port is taken, so look at the range too:

lsof -nP -iTCP:5173-5180 -sTCP:LISTEN

With Stat Space: statspace port 5173.

Free it

kill <PID> stops it cleanly. If several Node processes are piling up and their parent is 1, their terminals are long gone; see finding orphaned Node processes.

Change the port

vite --port 5200
npm run dev -- --port 5200

Note the extra -- with npm, which passes the flag through to Vite. To make it permanent, edit vite.config.ts:

export default defineConfig({
  server: {
    port: 5200,
    strictPort: true,
  },
});

For SvelteKit, the same server block goes in vite.config.ts, not svelte.config.js. Tauri projects pin Vite to 1420 instead, and Astro uses 4321.

Who can reach it

Vite binds to localhost by default. --host or server.host: true listens on all interfaces, and Vite prints a Network URL. With that on, anyone on your Wi-Fi can load your source files directly, because the dev server serves untransformed modules and source maps. Vite restricts which files it will serve outside the project root, but treat any exposed dev server as public. See dev server exposed to the network.

Seeing it live

Stat Space shows every Vite server on 5173 and above with its project folder, launcher and uptime, so the three copies of the same app are obvious. A --host server gets an exposure warning, and the row offers a QR code for opening it on your phone.