If Wi-Fi Can Go Through Walls, Why Is My Internet So Slow?

CNET

3 days ago

When it comes to your home internet connection, there's one question we get asked quite a bit: Does Wi-Fi travel through walls? The short answer is yes, but the long answer is a bit more complicated. I spoke with several experts, including CNET's Laboratory Technical Project Manager Gianmarco Chumbe, to find out everything you need to know about how Wi-Fi travels. It's a simple question, but it has a big impact on whether your Wi-Fi connection is slow.
"As with any radio signal, attenuation occurs when waves pass through materials like brick, concrete or metal -- or simply over increasing distance," Chumbe said. He should know -- our CNET Labs team has spent countless hours testing internet routers for the latest version of our Best Wi-Fi routers page.
With the introduction of Wi-Fi 6, Wi-Fi 6E and the latest standard, Wi-Fi 7, Wi-Fi technology has steadily improved in recent years. An adequate Wi-Fi connection is necessary, yet many people still struggle with their home internet: In a recent CNET broadband survey, 42% of respondents complained about having an unreliable connection.
Many possible factors contribute to an unreliable internet connection, but when it comes to Wi-Fi, there are quick fixes to boost the Wi-Fi connection throughout your home. To optimize your Wi-Fi connection and understand how the technology interacts with the structure of your home, you need to understand how Wi-Fi actually works.
Back to the basics
Wi-Fi, also known as Wireless Fidelity, is a wireless technology that allows your router to exchange data with multiple devices. This data is transmitted through radio waves. According to the Institute of Electrical and Electronics Engineers, the first version of Wi-Fi was released in 1997 under the 802 family of standards for local area networks. The IEEE designates Wi-Fi as 802.11.
Locating local internet providers
You'll primarily see three Wi-Fi standards when shopping for routers: Wi-Fi 6, Wi-Fi 6E and Wi-Fi 7. Most smart home devices in your abode should be compatible with Wi-Fi 6 and Wi-Fi 6E technology. Wi-Fi 7 has the potential to produce the fastest speeds and boasts the lowest latency of the three, though there are limited devices that are compatible with Wi-Fi 7 for now. Wi-Fi builds on features from the previous standards. If you have Wi-Fi 6, it'll have the 2.4 and 5GHz bands. Wi-Fi 6E added the 6GHz band, and Wi-Fi 7 doubled the 6GHz channel size.
According to Netgear, "Wi-Fi 7 helps to ensure your home is ready for 10 gigabit internet speeds as they become available."
That all sounds great in theory -- but what does that mean for your Wi-Fi at home?
How does Wi-Fi pass through walls?
Your router wirelessly exchanges data with other devices nearby through radio waves, which use electromagnetic radiation. As seen from the image below, Wi-Fi operates on these radio waves through the electromagnetic spectrum.
VectorMine/Shutterstock
According to ScienceABC, electromagnetic waves can pass through a surface; this process is called refraction. This is what allows Wi-Fi to pass through walls. It's worth mentioning that not all forms of electromagnetic radiation can permeate surfaces. Take Li-Fi technology, for instance. Li-Fi uses visible light, another form of electromagnetic radiation, to connect to the internet. Light signals can't pass through walls and other solid objects like Wi-Fi signals can.
Wi-Fi can pass through walls, but...
The thickness of your walls and the type of material used can obstruct or hinder Wi-Fi signals. According to Mistral Solutions, certain materials, like brick, plaster, cement, metal, stone and double-glazed glass, can obstruct Wi-Fi signals. Depending on the size and layout of your home, you might experience dead zones (areas where your internet signal is virtually nonexistent), laggy or extremely slow internet.
While a house full of cement walls would certainly cause problems for your router's Wi-Fi signal, the CNET Labs team determined that for most homes, the wall thickness wasn't the most significant impact on router signal strength after conducting tests. The distance from the router was a bigger determining factor. That said, changing the floor plan of your home may not be an option, but there are simpler things you can do to boost your Wi-Fi connection at home.
How to optimize your Wi-Fi
Several factors can affect the signal of your internet connection, such as walls, large obstructions and even electronics near your router.
Choosing the right router
The first step to optimizing your connection is determining whether you're using the right router. In most apartments and smaller homes (under 1,500 feet), a traditional router with a single wireless access point should be enough. CNET's top pick for the best wireless router is the Asus ROG Rapture GT-AX6000. After conducting tests on more than 30 routers, we found it was the only router to receive a top-five score from our throughput tests on both 2.4GHz and 5GHz bands. However, if you own a multistory home and want to prioritize internet coverage throughout, consider upgrading to a mesh router.
In some cases, you might need to toss out your old router and upgrade to a new one. Ideally, you should replace your router every five years. If you're in the market for new gear, consider upgrading to a new router or a router equipped with Wi-Fi 6 or the latest Wi-Fi 7. Almost any new device you've purchased in the past five years will be compatible with Wi-Fi 6, but only the latest phones, laptops and gaming consoles can take advantage of Wi-Fi 7.
The Wi-Fi band you use matters
Most routers are equipped with either 2.4GHz or 5GHz bands, and in some cases, they will come equipped with both. However, if your priority is to ensure that your internet connection reaches all areas of your home, choose a router with a 2.4GHz band. Here's why.
CNET broadband expert Joe Supan recently visited our CNET labs to help test routers. These tests provided metrics on speed, reliability and performance over distance. Our lab team also measured each router's signal strength and broadcast ability, showing how well data is transmitted through walls and around other electronics. The team marked off more than 61 locations around the lab to measure the performance of each router's 2.4GHz and 5GHz frequency bands. Though the 5GHz might offer you faster speeds, test results show that the 2.4GHz band has a better range.
"Most routers will automatically steer your traffic to the optimal band, but you can also set up separate Wi-Fi networks for each band if you want to prioritize devices like a gaming console or a work computer on the faster 5GHz band," Supan said.
"The important thing to know is whether it has both the 2.4GHz and 5GHz bands," Supan said. "Most routers will automatically steer your device onto the best one."
From left: The 2.4GHz band has better range but slower speeds, while the 5GHz band has faster speeds at close range.
Samantha De Leon/CNET
The team averaged all the data from the tests in a summary table. They then combined the scores to get one throughput metric for each frequency band. The data shows that routers with a 2.4GHz band outperformed those with a 5GHz band at long distances. Keep in mind that the typical indoor broadcast range of a router is 150 to 300 feet, according to the United States Computer Emergency Readiness Team.
Read more: How we test Wi-Fi routers
Router placement is key
In some cases, you may not need to take a dramatic step like getting rid of your router. Chances are, you may just be putting it in the wrong spot.
According to two technicians, here are five of the worst areas to place your router:
On the floor
Behind the couch
In the basement
Inside cabinets
Near another Wi-Fi router
The ideal spot for your router should always be centrally located in your home. I know routers aren't the prettiest gadgets, but resisting the impulse to hide them will only help boost your Wi-Fi. Also, keep in mind that placing your router in an area with large metal objects, nearby electronics or many walls can interfere with your Wi-Fi signal. If you can, try placing your router high on a bookshelf in a centrally located room.
Adjusting your Wi-Fi antennas
If you own a router that has antennas, positioning these antennas properly can improve your signal. If there are two or more antennas on your router, don't position them all in the same direction. The antennas should be perpendicular to one another -- one should be horizontal and the other should be vertical. If that still doesn't make a difference, try experimenting with placing the antennas at several different angles. During this process, run several internet speed tests to note the differences with each antenna configuration. CNET's top pick for the best speed test overall is Ookla for its consistency and reliability. (Disclosure: Ookla is owned by the same parent company as CNET, Ziff Davis.)
Invest in a Wi-Fi extender
A Wi-Fi extender will typically be a cheaper alternative to a mesh router if you're still experiencing laggy internet and dead zones after repositioning your router. Similar to a mesh router system, a Wi-Fi extender will help boost your speeds throughout your home. CNET's top pick for the best Wi-Fi extender is the Linksys RE7310. When tested, it delivered plenty of speeds, and it supports Wi-Fi 6 technology. If there are one or more rooms in your home that are dead zones, then a Wi-Fi extender could help improve the signal in these areas. You can either plug your extender into your router or into an outlet on your wall. If you live in a larger home and are facing issues with your connection, then a mesh router would be a better option.
Other things to consider about Wi-Fi
If all else fails, you might consider upgrading your router or switching internet service providers. Your internet trouble could be outside of your control, as some may experience throttled speeds from their ISP. If you're unsure whether your internet provider is to blame, read our guide on how to combat internet throttling. In addition, there are other drastic measures you can take to really improve your home internet connection. If you're serious about optimizing your connection, consider investing in a network switch. A network switch is a device you connect to your router, which opens up more Ethernet ports, allowing your router to connect to multiple devices. Investing in a quality network switch (Smart Managed or Fully Managed switches) may come with a steep price tag, but the benefits from using one could be worth the price: You can expect faster speeds, increased security and more control over your network.
Yes, Wi-Fi can travel through walls, but it's not magic
Yes, Wi-Fi technology allows your home internet connection to pass through walls, but you still need to take steps to optimize your Wi-Fi connectivity. The thickness of a wall can interfere with your internet signal, leaving you with dead zones in your home. Other factors, such as large objects and nearby electronics, can also cause your broadband connection to suffer.
As far as walls are concerned, of course, changing the layout of your home may not be an option. And before you make a hasty decision such as canceling your internet service or switching internet service providers, you can first try optimizing your Wi-Fi connection through the tips outlined on this page. If you're still running into trouble, then maybe it's time to consider whether you're facing a larger issue, such as throttled speeds from your ISP.
FAQ: Wi-Fi versus your walls
Can Wi-Fi travel through walls?
Yes, Wi-Fi can pass through walls. Wi-Fi technology operates on the electromagnetic spectrum and transmits data via radio waves. Data from your router is wirelessly transmitted to other devices nearby. Through a process called refraction, Wi-Fi signals are able to permeate walls, allowing your internet to travel throughout your home. However, this doesn't mean that you won't experience interference. The thickness of a wall can obstruct the signal from your router, leaving you with dead zones in your home. Other factors, such as large objects and nearby electronics, can also affect your Wi-Fi connection.
Where is the best place to put your router?
You should always aim to locate your router at a central spot in your home, away from many walls and large objects. Two technicians shared with CNET the five worst areas to place your router: on the floor, behind the couch, in the basement, inside cabinets and near another Wi-Fi router.
When should you replace your router?
Overall, experts recommend that you replace your router every five years. However, if there are many connected devices to your network, such as laptops, phones and more, experts suggest tossing your router out every two to three years.
There are plenty of well-performing Wi-Fi routers on the market. Read our top picks.