Testing Multiplayer: New Instances, Hotloading, and Local Connect
s&box provides built-in tools for testing multiplayer without needing another player. You can spawn additional game instances that join your running session, with live code hotloading across all connected clients.
Spawning a New Instance
Click the network status icon in the editor header bar and select "Join via new instance." A second game window appears and joins your session automatically.
Live Code Iteration
While the second instance is connected, you can continue coding on your main instance. Code changes are mirrored to all connected clients (including friends who joined) via hotloading — no restart needed.
Manual Connection
Open a second instance and run connect local in the console to manually join your local editor session.
Reconnecting
If a client disconnects, use the reconnect console command to rejoin without restarting.
Workflow
- Press Play in the editor (starts hosting)
- Click network icon → "Join via new instance"
- Test multiplayer interactions between the two windows
- Make code changes — both instances hotload automatically
- Use reconnect if the second instance drops