The real differences
| Feature | Ethernet | Wi-Fi |
|---|---|---|
| Speed | Full plan speed (up to the port's 1 Gbps or more) | Depends on distance, walls, band and other devices |
| Latency added | Under 1 ms | A few ms, with spikes when busy |
| Jitter | Near zero | Higher, especially on 2.4 GHz |
| Interference | None in practice | Neighbours' networks, Bluetooth, microwaves |
| Convenience | Needs a cable run | Works anywhere in range |
In short: The biggest gain from a cable is consistency, not just peak speed.
Why Wi-Fi is less consistent
Wi-Fi is a shared radio channel: only one device transmits at a time on a channel, and neighbours' networks on the same channel take turns too. Walls and distance reduce the signal, and the connection automatically drops to slower rates to stay connected. When a transmission fails, it's resent, which shows up as latency spikes and jitter.
None of that happens on a cable. That's why games and video calls that feel choppy on Wi-Fi often become smooth on Ethernet, even when the speed test result barely changes. Read more in what is jitter.
When a cable is worth it
- Gaming PCs and consoles: lower ping and far fewer lag spikes.
- Work computers used for calls all day.
- Smart TVs and streaming boxes near the router, especially for 4K.
- Mesh nodes and access points: a wired link (“wired backhaul”) makes the whole mesh faster.
- Testing your connection: a cable is the only way to tell whether a slow result is Wi-Fi or the ISP.
Choosing a cable
Any certified cable from Cat 5e up supports Gigabit, faster than almost every home plan today.
| Category | Speed | Notes |
|---|---|---|
| Cat 5e | 1 Gbps up to 100 m | Fine for home use |
| Cat 6 | 1 Gbps up to 100 m; 10 Gbps over shorter runs (~55 m) | Good default for new cabling |
| Cat 6a | 10 Gbps up to 100 m | Thicker; for future multi-gig |
Can't run a cable? Alternatives
- Mesh Wi-Fi: several units spread across the home; best with a wired link between them where possible.
- Powerline adapters send data over electrical wiring. Results vary a lot with the wiring and don't work well across separate circuits or through some UPS/inverter setups.
- Moving the router to a central spot often helps more than any gadget (router placement).
How to measure the difference yourself
Run the speed test on a laptop connected by cable, then again on Wi-Fi in the same spot and in the room where you usually work or play. Compare download, upload and especially latency under load and jitter. If the cable result is good but Wi-Fi isn't, your ISP is fine and your Wi-Fi setup is the thing to fix.
Common questions
Is Ethernet always faster than Wi-Fi?
For stationary devices, practically yes: a cable delivers your full plan speed with lower, steadier latency. Close to a modern router, Wi-Fi can match plans up to a few hundred Mbps, but it varies more from moment to moment.
Which Ethernet cable should I buy?
Cat 5e or Cat 6. Both handle 1 Gbps up to 100 m, which covers every home plan. Cat 6 also supports 10 Gbps over shorter runs. Avoid very cheap flat cables with unknown ratings for long runs.
Why does my wired connection show only 100 Mbps?
The link negotiated Fast Ethernet instead of Gigabit. Usually a damaged cable or plug (Gigabit needs all eight wires), an old cable, or a 100 Mbps port on the router or device. Try another cable and port.