Your Ethernet cable should be faster than WiFi, but speed tests show the opposite. WiFi gets 300 Mbps, wired gets 100 Mbps or less.

Something's limiting your wired connection. Here's what to check:

1. Bad or Old Cable

Cat5 cable maxes out at 100 Mbps. Cat5e and Cat6 handle gigabit speeds.

Look at the cable. Should say "Cat5e," "Cat6," or "Cat6a" printed on it. If it says just "Cat5" or nothing, that's your problem.

Replace with Cat6 cable. Costs $10-15.

Also check if cable is damaged. Bent, crushed, or chewed cables cause slowdowns.

2. Plugged Into 100 Mbps Port

Some routers have one gigabit port (usually yellow) and the rest are 100 Mbps (gray).

Check which port you're using. Plug into a different port and test again.

To verify link speed on Windows:

Command 
Control Panel > Network Connections > Right-click Ethernet > Status

Should show "1.0 Gbps" not "100 Mbps"

On Mac: Hold Option, click WiFi icon, shows link speed.

3. Network Adapter Locked to 100 Mbps

Your network card might be configured wrong.

Windows fix:

  1. Device Manager > Network adapters
  2. Right-click your Ethernet adapter > Properties
  3. Advanced tab
  4. Find "Speed & Duplex"
  5. Change to "Auto Negotiation" or "1.0 Gbps Full Duplex"
  6. Click OK

Test speed again.

4. Router Port Is Dying

The specific Ethernet port on your router might be degraded.

Test: Plug into a different port on the router.

If speed improves, that port is bad. Use a different one or get a network switch.

Quick Diagnostic

Run this in order:

  1. Check cable (says Cat5e or Cat6?)
  2. Check link speed (shows 1 Gbps?)
  3. Try different router port
  4. Try different cable
  5. Check adapter settings (auto negotiation on?)

One of these is the culprit.

Why This Happens

Most common: Cat5 cable or 100 Mbps router port limiting speed.

Less common: Network adapter driver issue or bad cable.

Rare: Router port physically damaged.

Ethernet should always beat WiFi for speed and latency. If it doesn't, you've got a bottleneck somewhere in the physical connection.

Replace cable with Cat6, verify 1 Gbps link speed, try different ports. Done.