The solution explains how to monitor bandwidth usage per device on a wifi network. There are two ways by which you can achieve this solution.
How to monitor bandwidth usage per device using wifi router
Your wifi router can monitor the bandwidth usage per device on your home or office wifi network. But the router should have the feature supported on it. You could check the specifications on the router to check if it supports.
If it does not, you could plan to upgrade your router. The Asus router with adaptive QOS feature have the capability to monitor internet usage.
The ASUS AX6000 WiFi 6 Gaming Router (RT-AX88U) which supports adaptive QOS is highly recommended. The details of the router and how it is used to achieve the solution is explained below.
How to monitor bandwidth usage per device using Asus router
The router has the bandwidth monitor feature inbuilt.It can be used to view the bandwidth usage of each device individually. The screenshot of the bandwidth usage by user is shown below. (Image reference from Asus portal)
The bandwidth usage of each device on the network is displayed. The router also shows the upload and download data usage for the devices.
How to monitor bandwidth usage per device using network analyzer
Wireshark is a free network analyzer which can also be used to monitor bandwidth usage on a network. This is a more technical approach and you should have sound knowledge on how to setup it up for network bandwidth monitoring.
The above two solutions would allow to monitor the bandwidth usage per device on a network. It is recommended to use a router with the capability. The complexity of this solution would be much simpler when compared using a network analyzer.