There are a few requirements.
UPDATE: While the below option still works for many Android Smartphones there is a new better way to connect to Ethernet. Using a Type-C Hub can add many ports including HDMI, VGA, Ethernet, Old USB standards, and SD-Card port. Type-C Hubs also have much better compatibility.
Android Ethernet Requirements
- First Android Marshmallow 6.0.1 which was released October 2015 must be installed.
- Second an OTG to Ethernet adapter will be needed.
Previous Android versions needed to be rooted which is no longer the case with Android Marshmallow 6.0.1 and above.
The Ethernet adapter will transmit the signals over the network. These items can be bought separately or in one package ready to go.
Not all the adapters are compatible with every Android device and should be verified it works with your device.
While most will not have any problems the Chipset in the adapter and the phone/tablet must be compatible. Simply be sure an adapter will work with your Android device before getting one.
Be sure to know what type of port your phone uses, old Micro-USB or the new Type-C.
Most older Android smartphones use a Micro-USB port with the new Type-C port now on the Galaxy S10, S20 and similar units.
Micro-USB OTG to Ethernet Adapter on Amazon
Plugable USB 2.0 OTG Micro-B to 100Mbps Fast Ethernet Adapter Compatible with Windows Tablets, Raspberry Pi Zero, and Some Android Devices (ASIX AX88772A chipset).
Type-C Android Ethernet Adapter on Amazon
USB C to Ethernet Adapter RJ45 to Type C Gigabit Network LAN Converter 10/100/1000Mbps for MacBook Pro Air/iPad Pro/Galaxy S20 S10 S9 XPS 13 15 /Surface Book 2 Go Chromebook-Silver
Most Android devices simply need to be plugged in and will automatically connect. Be sure to turn off your WiFi to know for sure it is only on Ethernet.
Some devices require it to be in Airplane mode in settings and depends on the ROM.
Hooking an Android smartphone or tablet to an Ethernet line is easy to do, with Android Marshmallow or higher.
While most will not have any issues the phone or tablet must have the drivers for the chipset in the Ethernet adapter to work.
Every manufacture customizes the Android OS for their devices and may remove or add drivers.
Simply be sure to read the specs of an adapter and the reviews to be sure it works with your smartphone or tablet.