My internet is slow only on WiFi but fast on ethernet. Is this the router, the device, or something else

[Kai_37]

Ethernet directly to the router gives me full speed, around 500Mbps. WiFi on the same device gives me 50 to 80Mbps from the same room. The router is about three years old. Is this a router problem or a WiFi adapter problem in the device?

Running a dual band router, device connects on 5GHz

[Ruby92]

Three years old and 50 to 80Mbps on 5GHz in the same room is not normal. Something is wrong. That should be giving you 200Mbps minimum with a halfway decent setup

[LuckySentinel]

Check what WiFi standard the device is using. If it is connecting on WiFi 5 (802.11ac) rather than WiFi 6 (802.11ax) you are leaving speed on the table. Look in Device Manager under Network Adapters for the adapter spec

[PlanckLimit81]

Channel congestion is the most common culprit in a dense area. Download WiFi Analyzer on your phone and see how many networks are on the same channel as yours. Switch to a less congested channel manually in the router settings

[QuantumLeap]

Check if the router is running the latest firmware. Three-year-old routers often have firmware updates that significantly improve WiFi performance and stability

[RomanReigns02]

Also check if you have any Quality of Service settings enabled on the router that might be throttling wireless traffic differently to wired

[GreenEcho]

The 5GHz band has shorter range but less congestion. If you are genuinely in the same room the range is not the issue. Interference from other devices like microwaves, baby monitors, or cordless phones on similar frequencies is worth ruling out

[Matticus]

Try connecting another device to the same WiFi. If that device gets full speed the problem is the WiFi adapter in the slow device. If it is also slow the problem is the router

[QuantumLeap96]

A three year old router that is not wifi 6 is going to struggle in a house with many connected devices. The practical upgrade path is a WiFi 6 router or a mesh system if you need coverage beyond one room

[Chris27]

Check the router placement. Even in the same room, obstacles between the router and device matter. Metal objects and appliances between them can reduce 5GHz signal significantly