Wi-Fi vs Ethernet: Why Your Speed Test Results Differ

If you've ever run a speed test on Wi-Fi and then plugged in an Ethernet cable, you've probably noticed a significant difference. Here's why — and when it actually matters.

The Wi-Fi Speed Tax

Wi-Fi adds overhead to every packet your device sends and receives. This overhead comes from several sources: signal encoding, interference management, shared airtime, and retransmissions due to packet loss.

Typical Wi-Fi overhead: 20-40% reduction in throughput compared to wired Ethernet. On a 200 Mbps connection, you might see 120-160 Mbps on Wi-Fi.

Why Latency Differs

Wi-Fi doesn't just affect speed — it significantly impacts latency (ping) and jitter. A wired Ethernet connection typically delivers 1-3ms of local network latency, while Wi-Fi adds 5-20ms or more, with much higher variability.

When Wi-Fi Matters Most

Gaming: The jitter introduced by Wi-Fi causes rubber-banding and inconsistent hit registration. Competitive gamers should always use Ethernet.

Video conferencing: Wi-Fi jitter causes audio drops, video freezing, and lip-sync issues. For important meetings, plug in.

4K streaming: Wi-Fi throughput inconsistency can cause buffering. If you're getting buffering on a fast connection, try Ethernet.

When Wi-Fi Is Fine

For general web browsing, social media, email, and standard definition streaming, modern Wi-Fi (Wi-Fi 5 or 6) is more than adequate. The convenience often outweighs the performance difference.

Testing Tips

Our Recommendation

Run your baseline speed test on a wired connection. This gives you your true ISP speed. Then test on Wi-Fi to see how much your wireless network is costing you. If the gap is large, our diagnostics page can help you optimize your Wi-Fi setup.