Why you can trust ZDNET
:ZDNET independently tests and researches products to bring you our best recommendations and advice. When you buy through our links, we may earn a commission.Our process
'ZDNET Recommends': What exactly does it mean?
ZDNET's recommendations are based on many hours of testing, research, and comparison shopping. We gather data from the best available sources, including vendor and retailer listings as well as other relevant and independent reviews sites. And we pore over customer reviews to find out what matters to real people who already own and use the products and services we’re assessing.
When you click through from our site to a retailer and buy a product or service, we may earn affiliate commissions. This helps support our work, but does not affect what we cover or how, and it does not affect the price you pay. Neither ZDNET nor the author are compensated for these independent reviews. Indeed, we follow strict guidelines that ensure our editorial content is never influenced by advertisers.
ZDNET's editorial team writes on behalf of you, our reader. Our goal is to deliver the most accurate information and the most knowledgeable advice possible in order to help you make smarter buying decisions on tech gear and a wide array of products and services. Our editors thoroughly review and fact-check every article to ensure that our content meets the highest standards. If we have made an error or published misleading information, we will correct or clarify the article. If you see inaccuracies in our content, please report the mistake via this form.
How to convert your home's old TV cabling into powerful Ethernet lines
If you 'cut the cord', you probably have yards of now-useless coaxial cable in your walls. In this guide, we show you how to turn that dormant cabling into an integral part of your home network with just a couple of adapters.
If you're not already familiar with it from doing self-installs of set-top boxes or broadband modems, coaxial cable (seen above) is that round, usually white, sorta stiff cable that carried all forms of pay TV services, including cable and satellite-based subscriptions. The cabling was run throughout just about every home that ever had a pay TV or internet connection for several decades.
But, as technology marched on, many of use moved away from these TV services in favor of streaming our TV and movies over the internet. While this left many homes still using a single coaxial cable line to carry their broadband signal to a modem, even those have often been replaced by Ethernet due to many ISPs requiring its usage for any service tier over 100Mbps.
Because of these transitions, millions of homes find themselves with seemingly useless coaxial cables and coaxial outlets emerging from walls and floors. But, don't rip all that cabling out just yet. With a couple of relatively inexpensive adapters, you can use those lines that already spiderweb across your home to carry the same data that would otherwise require hundreds of feet of expensive-to-install Ethernet cabling.
In fact, it can connect any two devices that use Ethernet connections – modems, routers, switches, PCs, streaming devices, and more – even if they're on opposite sides of the house. Read on to find out how to turn that idle coaxial into a ready-to-go, whole-home networking asset.
How to convert your home's coaxial cable into Ethernet lines
Materials needed: Built-in coaxial cabling, a coaxial-to-Ethernet adapter kit, any networking hardware you're hoping to connect
Estimated time: 30 minutes
Estimated cost: $115 to $150 (depending on adapter model)
1. Locate the coaxial cable line you want to adapt
The first, and often most difficult, step in this process is locating the coaxial cable line you want to adapt to Ethernet. Since most cable runs are within walls, it's hugely helpful if the cable is labeled at both endpoints. Unfortunately, that's not always the case.
This is a great time to have a friend or family member on the phone with you to help this process. If you have a bare coaxial line emerging from the wall, it may be as simple as having them jiggle one end while you watch the other for movement. Or, if you have a built-in outlet, it may take a little more detective work to visually verify which line is which.
If worse comes to worst, the rest of the process is simple enough that you can just take your best guess and, if you've gotten it wrong, you can start over with your next best candidate for which line it is that's running to your desired endpoint. Or, if you're short on time, there's a hugely helpful tool we cover in the FAQ section below that can speed things up.
2. Connect your first adapter
Once you have your line of choice verified (or you've taken your best guess), the next step is to begin connecting the adapter kit you've purchased. We've included several adapter candidate below, and would suggest choosing whichever model best suits your goals for speed and security.
To install the adapter, you'll need to make a total of three connections:
Coaxial cable: will screw into the port marked G. Hn., In, or MoCa (Multimedia over Coax Alliance), depending on your model
Ethernet: will click into the Ethernet port
Power: should usually be connected last
The power adapter type will vary from manufacturer to manufacturer, but is almost always needed to provide the current used to convert and carry your Ethernet signal over coax.
Some adapters may also have a TV or Out port for a second coaxial cable. This is used if you still want the same cable to carry a TV signal. While it is possible to keep an active cable or other pay TV connection running over the same line, we'd recommend avoiding it. The two competing signals have the potential to interfere with each other, leading to poor performance for both.
3. Connect your second adapter
This is the same as the previous step, just performed again at the other end of your chosen coaxial cable run.
The placement of each adapter depends entirely on your goals for this new coax-to-Ethernet run. For example, if you're attempting to connect your incoming broadband connection to a modem or router that will be located elsewhere in your home, you'll want one adapter wherever the broadband connection enters your home, and the other located wherever you want your router, with a coaxial line located between them.
Likewise if you want a hardwired connection running from an existing router to a basement home theater setup for reliable 4K (or even 8K) streaming, you'd place one adapter near the router and the other near your home theater.
The important thing is to think of these adapters as nothing more than endpoints for a run of Ethernet. With their help, that's exactly what any old run of coaxial cable can become.
4. Connect all of your other networking hardware
Once you've got your adapters up and running, the final step is to connect any network hardware you want joined by your newly created connection. This can include anything like the examples in Step 3, as well as other streaming devices, network switches, PCs, wireless network extenders, and similar tech. Again, anything that could normally connect via Ethernet is a candidate.
Once you've connected your other networking hardware and verified the connection is up and running, you should be good to go with your new home networking setup.
You can also repeat this entire process to convert other runs of coaxial cable to Ethernet, but you'll need another set of adapters for each.
Which adapter should I buy?
This depends entirely on your goals for the run, the level of security you want, and other factors specific to your home and devices. However, we've collected a few good candidates for the most common scenarios below.
A starter kit that supports MoCa 2.5 for running entire home networks over a single coaxial cable. A great option for those upgrading to a faster broadband tier that might otherwise require Ethernet installation.
A cheaper alternative to the above model that offers very similar features but comes with a few less adapters that you may need to provide yourself, depending on your situation.
Can I use this method to connect my entire home to my ISP?
Yes. One of the main reasons why adapters like these are most commonly used is to help customers upgrading from slower (100Mbps or so) broadband connections to something faster (300Mbps or more). Since many broadband connections above 100Mbps require Ethernet cabling to be run from their origination point to a modem or router, lots of customers were stuck with a huge bill to replace their existing coaxial connections (which were fine up to 100Mbps) with the required run of Ethernet. Instead, these adapters offer a way to convert that existing coax into Ethernet at both ends, letting you connect broadband hardware, even hardware running at up to 1Gbps, to a modem or router over your existing coaxial cable.
If you're planning to do this, we would recommend choosing an adapter kit that uses the "bonded MoCa 2.5" protocol. This is a standard created by the Multimedia over Coax Alliance (MoCa). It's rated for up to 2,500Mbps (2.5Gbps), and was designed to carry the kind of traffic an entire network is likely to create. Other adapters may work, but you could experience some slowdown based on what specific protocols and technologies they support. Obviously, you don't want to pay for gigabit broadband only to be accidentally throttling yourself to less than 300Mbps by using the wrong hardware.
What if I'm having trouble figuring out which coaxial line is which?
In homes that had lots of TV all hooked up to cable or satellite hardware at one point, you could be dealing with dozens of lines of coax running through walls. If you're not lucky enough to have them helpfully labeled for you, it may seem too daunting to trace each run. Thankfully there is a very helpful tool that can expedite the process.
This inexpensive gadget lets you plug one end of it into a run of coaxial cable, go to the other end, and screw on a tiny speaker. If you hear a tone, you've found a complete run. If not, you need to try another endpoint. It's a huge help if you have in-wall coax outlets that prevent the "jiggle it" method, or if you don't have any help handy to sit at the other end. I'd recommend picking one up if you're serious about making use of your home's defunct coax for more than one run.
What are some other uses for converting coaxial cable into Ethernet?
As mentioned above, essentially anything that could be handled by a run of Ethernet could also be done by a coaxial cable with the appropriate adapters at either end. But, just to set you on the path to how varied those possibilities are, we'll include a handful of other example scenarios below. You could...
Use a run of coaxial cable to create a hardwired connection to a Wi-Fi extender to counteract a Wi-Fi dead zone in your home or office.
Connect a gaming PC over adapted coax to reduce the game-breaking latency Wi-Fi can sometimes introduce.
Create a fast, wired connection between a NAS (Network Accessible Storage) device and a remote computer or media streaming setup.
Install an over-the-air broadcast antenna and receiver that you'll use with adapted coaxial cable to connect to your LAN for streaming or recording.
Skip the hundreds or thousands of dollars a contractor might charge to install any in-wall runs of Ethernet cabling for any other purpose.