I'll be honest: I spent years thinking Ethernet cables were relics from the early 2000s. My Wi-Fi worked fine. My phone, my laptop, my TV — all connected wirelessly, all perfectly happy. Then I plugged my desktop into the router with a $5 Cat6 cable, ran a speed test, and felt like an idiot for not doing it sooner.
But the truth is more nuanced than "cables are always better." Sometimes Wi-Fi is genuinely fine, and dragging a cable across your apartment isn't worth the hassle. So let's talk about when the cable matters and when it doesn't.
The speed difference (and why it's often irrelevant)
A standard Ethernet cable (Cat5e or better) supports gigabit speeds — 1,000 Mbps. Modern Wi-Fi 6 can also hit gigabit speeds, in theory. In practice, Wi-Fi rarely sustains those speeds for more than a few seconds because it has to deal with signal interference, wall penetration, distance from the router, and the fact that it's a shared medium (every Wi-Fi device is essentially shouting into the same room and hoping to be heard).
But here's the thing: unless you're regularly transferring huge files between devices on your local network, or your internet plan exceeds what your Wi-Fi can deliver, the speed difference is academic. Streaming Netflix at 4K uses about 25 Mbps. Even mediocre Wi-Fi handles that without breaking a sweat. Browsing the web, checking email, scrolling social media — none of these activities come anywhere close to saturating a modern wireless connection.
Latency: Where Ethernet actually wins
This is the real reason to use a cable, and almost nobody talks about it in the right way. Speed is about how much data you can move per second. Latency is about how quickly any single piece of data gets from point A to point B. On Ethernet, latency is almost zero — sub-millisecond. On Wi-Fi, it's typically 2 to 10 milliseconds, and it can spike to 50ms or more when the network is congested.
For gaming, this is the difference between a responsive experience and one where you feel like your inputs are delayed. For video calls, it's the difference between smooth conversation and that awkward moment where both people start talking at the same time because the audio is slightly behind. For file transfers and backups to a NAS on your local network, Ethernet is so much faster that it feels like a different technology entirely.
Reliability: The underrated factor
Wi-Fi connections drop. Not always dramatically — sometimes it's a brief hiccup, a momentary slowdown, a single packet lost in the noise. You don't notice it when you're reading an article, but you absolutely notice it when you're in the middle of a ranked match or a job interview over Zoom. Ethernet doesn't do this. A wired connection is either working or it's not. There's no signal strength to worry about, no interference from the microwave, no congestion from the neighbor's baby monitor. It just works.
This stability is also why every serious home server setup, every NAS, every media server, and every workstation in a professional environment uses Ethernet. It's not about speed — it's about predictability.
When to use what
Use Ethernet for anything that sits in one place and needs consistent performance: your gaming console, your desktop PC, your smart TV, your NAS. These devices don't move, and a one-time cable run gives you permanently better performance.
Use Wi-Fi for anything that moves or doesn't need rock-solid performance: your phone (obviously), your laptop when you're on the couch, your tablet, your smart speaker. The convenience of wireless massively outweighs the marginal performance benefit of a cable for these devices.
And if you can't run cables because you're renting or your router is in the wrong room? Look into powerline adapters or MoCA adapters. They're not as good as direct Ethernet, but they're significantly better than Wi-Fi for stationary devices, and they use your existing electrical or coax wiring. No drilling, no cable stapling, no landlord complaints.