Check the Ethernet link speed first. If the connection is stuck at 100 Mbps, a cable, wall jack, adapter or router port is limiting it no matter how fast your internet plan is.
Quick checks before changing settings
CheckWhat it tells youLikely direction
Is link speed 100 Mbps?Your cable path is capped before the internet is even tested.Cable, port or adapter
Does another cable fix it?The old cable may be damaged or not wired for gigabit.Cable
Is Wi-Fi faster on the same device?The device can reach higher speeds, so focus on the wired path.Ethernet path
Does a direct router connection help?A wall jack, switch or long cable run may be the bottleneck.Home wiring
Try these fixes in order
- 01
Check the negotiated link speed
Look for the Ethernet status on the computer or router. A 100 Mbps link is the giveaway; the connection can never exceed that by much.
- 02
Try a short known-good cable
Use a short Cat5e or Cat6 cable directly into the router. This removes wall plates, switches and long cable runs from the test.
- 03
Move to another router port
A single damaged or lower-speed port can make one wired device look broken while the rest of the network is fine.
- 04
Check USB adapters and docks
Some adapters overheat, use older standards or perform poorly through a dock. Test directly if possible.