If you have cable Internet, you probably rent your modem from your service provider for a monthly fee, the same way you do your cable box. You may already have your own wireless router, though many cable companies offer those for rent, as well. But did you know that with most Internet Service Providers (ISPs) you can buy your own modem and save those monthly fees?
There are some benefits to renting, however. When you rent a modem, you'll often pay a monthly fee that's less than $10, but will still one day exceed the purchase price, but you can trade the modem in when it becomes obsolete or if it stops working. Plus, you don't have to worry about compatibility or replacing the unit yourself. Some ISPs include the cost of a modem in your package pricing, so you won't save any money by purchasing your own, but you will be able to continue to use the same one if you change providers. Bottom line: It's not terribly straightforward. Here's how to get the best deal.
When to Buy Your Own Modem
Before we dive in, let's talk about modem technology, which affects your maximum upload and download speeds in addition, of course, to the service offered by your cable provider. The Data Over Cable Service Interface Specification (DOCSIS) is a telecommunications standard used to provide Internet access over a cable modem. The current standard is DOCSIS 3.0, which offers some of the highest speeds available. Gigabit Internet is faster, but it's found only in select cities around the country, as you can see on Google's map of Gigabit coverage. This speed will eventually require the DOCSIS 3.1 standard, which for now is available in just a few test markets; very few compatible modems are currently available.
You'll definitely want to upgrade your modem if it only supports DOCSIS 2.0, as you'll be sacrificing speed, and ISPs likely won't continue to support them for much longer. In any case, it's worth contacting your ISP if you're not sure about compatibility.
Internet speeds are measured in two ways: upstream and downstream, aka uploads and downloads. Originally, DOCSIS used one channel for downloading data and one channel for uploads. DOCSIS 3.0 enables modems to combine multiple channels to stream data, increasing the speed of both downloads and uploads. Most users will want a 16x4 or 8x4 modem—that is 16 or eight downstream channels and four upstream channels. A 16x4 modem generally tops out at around 680Mbps for downloads, while an 8x4 modem will offer maximum download speeds of about half that, 340Mbps. Some high-speed plans require a 24x8 modem, but you should check whether your ISP allows you to use your own modem before purchasing one.
If you're currently renting a cable modem, check your monthly bill for the rental fee, which generally ranges from $5 to $10. Among the major cable companies, Comcast, Optimum, and Spectrum (formerly Time Warner Cable) each charge fees; Charter includes the cost in its Internet plans, while Cox offers a free modem if you bundle a TV and Internet plan, which you likely already do. This means, aside from Cox, you could save between $60 and $120 per year, which means a modem that costs $90 to $100 would pay for itself in less than a year. Be sure that your cable company stops charging you the rental fee, though; it may "forget".
Choose a modem that's compatible with major cable ISPs in the US in case you move or decide to change service. (Major ISPs typically list compatible modems on their websites.) And be sure the modem supports the speeds you're paying for. If Gigabit Internet is on the horizon in your community and you plan to upgrade your plan, get a modem with a Gigabit Ethernet port.
When Not to Buy a Modem
Of course, there are exceptions. If you have or switch to DSL or fiber you can't use a cable modem; each uses special equipment that you'll have to rent or purchase from your ISP. In addition, if you bundle your home phone service with your Internet plan, you'll need a modem that has a phone port. Telephony modems aren't widely available for sale—a quick search yields expensive products with outdated technology—so you're most likely better off renting from your ISP.
The Right Cable Modem for You
At PCMag, we don't rate cable modems because it's not possible to isolate modem performance from ISP speed, and we're unable to test them with every compatible ISP under the same conditions. The right cable modem for you is compatible with your ISP and your particular plan, and offers the best balance of price and features. The best modems overall support DOCSIS 3.0, and are compatible with all the major US cable companies, namely Charter, Comcast, Cox, and Spectrum, which is true of all the modems listed below. Each model here costs less than $100, so if you're paying $10 a month to rent your modem, you'll make back your investment in less than a year. And three of the four modems below include a Gigabit Ethernet port, so you'll be ready when Gigabit Internet is available in your area.
The Arris Surfboard SB6141 8x4 modem ($70) provides maximum speeds of 343Mbps download and 131Mbps upload, but it lacks a Gigabit Ethernet port.
The Arris Surfboard SB6183 ($90) ups the ante with download speeds up to 686Mbps and 131Mbps maximum upload speeds as well as a Gigabit Ethernet port. It has 16 downstream channels and four upstream channels. If you have the extra $20, it's worth it to upgrade to the SB6183 over the SB6141. Both Arris modems come with a two-year warranty.
The Netgear CM500 High-Speed Cable Modem ($95) has 16 downstream channels and four upstream channels, which results in download speeds of up to 680Mbps. It also has Gigabit Ethernet port. Netgear offers a one-year warranty that includes free support within the first 90 days of purchase, as long as you register your product.
The Zoom 5345 cable modem ($45) has eight downstream and four upstream channels, resulting in download speeds of up to 343Mbps; it also sports a Gigabit port. Like Arris, Zoom offers a two-year warranty on its modems.
Once you have your new cable modem hooked up, you'll want to make sure you're getting the best speeds on your network. Check out our tips for setting up your router and getting the most from it, boosting your Wi-Fi signal, and testing your connection speed.
Want something even easier to use than a traditional router? Read about our top-rated Wi-Fi mesh networking systems. And if you're looking for a new Internet provider, our annual fastest ISPs and fastest gaming ISPs surveys will help you find one.