To view localhost website from mobile device you have to follow thoses steps :
- In your computer, you have to retrieve your IP address (Run > cmd > ipconfig)
- If your localhost use a specific port (like localhost:12345 ), you have to open the port on your computer (Control Panel > System and Security > Firewall > Advanced settings and add Inbound rule)
- Finally, you can access to your website from mobile device by navigate to : http://192.168.X.X:12345/
Hope it helps