I'll show you how to check the Gatsby site that is under development on an actual smartphone or other device.
The IP address of the development machine may be different for each OS because it has been tested on mac.
Get an IP address by ifconfig command
> ifconfig . .... .... en0: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500 options=400<CHANNEL_IO> ether xx:xx:xx:xx:xx:xx inet6 fe80::18e8:b8eb:c36b:8185%en0 prefixlen 64 secured scopeid 0x6 inet 192.168.1.xxx netmask 0xffffff00 broadcast 192.168.1.255 nd6 options=201<PERFORMNUD,DAD> media: autoselect status: active ... ... .... ....
The above shows that the IP address in the LAN is 192.168.1.xxx.
Add 0.0.0.0.0 to the host's options
Defaults to localhost -H, --host Set host.
> gatsby develop -H 0.0.0.0
After confirming that it is running on localhost:8000, you can use a browser on a smartphone connected to Wifi in the LAN to
Based on the IP address acquired earlier, you can access the terminal where the development mode of Gatsby is running on the default 8000 port.