By Rob Larson, VP, Design and Construction at Ziply Fiber

If you've ever run an internet speed test and wondered why the results don't match the plan you signed up for, you're not alone. Sometimes, it might be due to limitations of your device hardware; however, in many cases, the issue isn't your internet service at all. It's how your device is connected.

That usually comes down to one question. Are you using WiFi or Ethernet?

Both connect you to the internet. Both have a place in your home. But they work differently, and understanding those differences can help you get better performance, more reliability and more value from your connection.

The big picture difference

The primary difference between WiFi and Ethernet is how data travels from your internet connection to your device. WiFi sends data wirelessly through radio signals, while Ethernet sends data through a physical cable. That one change in delivery method affects speed, stability and consistency in ways that matter for everyday use.

How WiFi works

WiFi starts with your router. Your router takes the internet connection coming into your home and broadcasts it as a wireless signal. Your devices connect to that signal and send data back and forth through the air.

The biggest advantage of WiFi is flexibility. You can connect phones, laptops, tablets, smart TVs and gaming consoles without running cables throughout your home. You can move from room to room without losing your connection.

But wireless signals are affected by:

The farther your device is from the router, the more likely speeds will drop. Interference can also cause fluctuations in performance, especially during video calls or online gaming.

For most everyday activities like browsing, streaming and checking email, WiFi works great. Just keep in mind that it adds another layer between your device and your internet connection.

How ethernet works

Ethernet removes that wireless layer.

Instead of sending data through the air, it uses a physical cable to create a direct connection between your device and your router or network equipment. That dedicated path means less interference and more consistent performance.

In practical terms, Ethernet often delivers:

That's why gamers, remote workers and content creators often prefer a wired connection for their primary devices.

The tradeoff is mobility. Because you're physically connected to a port, you're limited as to where you can sit unless you run cables to other rooms.

When WiFi makes the most sense

WiFi is typically the best choice if you:

Modern WiFi networks are powerful and reliable for most households. With good router placement and proper setup, they handle multiple devices at once without much trouble. It's useful to know the maximum capabilities of your router as they've continued to advance to support more devices and speed.

When ethernet is the better option

Ethernet is usually the better choice if you:

If performance consistency is critical, a wired connection gives you the clearest picture of what your internet plan can deliver.

Ethernet can also be a cost-effective option. In many cases, all it takes is an inexpensive, widely available Ethernet cable to get a faster, more reliable connection. If a room doesn't already have an Ethernet port, a technician can install one and run a cord to the space where you need it, making it easy to connect directly without reworking your entire setup. It's easiest if it's close to the router location.

Many homes use both. WiFi for convenience and Ethernet for high performance devices.

How to run a speed test the right way

Before assuming something is wrong with your internet service, it helps to test your connection properly.

For the most accurate results:

  1. Connect your device using Ethernet if possible
  2. Pause streaming and downloads on other devices
  3. Close unnecessary apps or browser tabs
  4. Stand close to your router if testing over WiFi
  5. Run the test multiple times at different times of day

If you test using WiFi, you're measuring both your internet speed and your wireless conditions. If you test using Ethernet, you're measuring your direct connection to the network.

That difference matters. A slower WiFi result doesn't always mean your internet plan is underperforming. There will be variability for WiFi even within your home.

How to plug ethernet into your ONT

If you have fiber internet service, your home set-up includes a device called an Optical Network Terminal, or ONT. This device converts the fiber signal coming into your home into a signal your router can use.

In other words, the ONT is the point where fiber internet enters your home.

To connect via Ethernet:

  1. Locate your ONT. It's often mounted on a wall in a garage, utility room or basement
  2. Find the Ethernet port on the ONT
  3. Plug one end of an Ethernet cable into that port
  4. Plug the other end into your router's Wide Area Network (WAN) or Internet port
  5. If you're testing directly, plug the cable into your computer's Ethernet port

In most cases, your device will automatically recognize the wired connection. No complicated setup is required.

If you're troubleshooting or running a speed test, connecting directly from the ONT to a computer can help isolate whether the issue is inside your home network or with the incoming connection.

A parting thought

WiFi gives you flexibility and convenience. Ethernet gives you performance and consistency.

Neither is universally better. The right choice depends on what you're doing and how important stability is for that task.

If your connection feels inconsistent, switching a key device to Ethernet can make a noticeable difference. If you value mobility and simplicity, WiFi remains a strong and reliable option.

Understanding how each connection works helps you make smarter decisions, run better speed tests and get the most from your fiber internet.

About the author

Rob Larson leads Ziply Fiber's Design and Construction team, guiding the vision, strategy and execution behind the network expansion that brings high performance fiber connectivity to communities of every size.