If you have cable internet, you probably rent your modem from your internet service provider for a monthly fee on top of your internet plan. It's usually somewhere between $5 and $10 a month, though most ISPs are less than up front about how much their services cost.
Many providers allow you to buy your own modem and avoid those monthly rental fees. While there are obvious benefits to buying your own modem, there are still reasons you may prefer to rent it from your ISP. Here's all the information you need to decide for yourself.
Why Buy Your Modem
Check your monthly bill for a rental fee; Comcast, Cox, Optimum, and Spectrum all add a charge, depending on your plan. Some providers say they provide a free modem in certain bundles, but they usually charge an extra Wi-Fi service fee if you use a modem/router combo unit (like Spectrum, pictured above).
If you are allowed the option to use your own modem, you could save between $60 and $120 per year by buying one instead of renting it from your ISP. Sure, you may pay $50-$100 upfront, but you will have recouped the cost of those fees within a year, and will then start saving $10 a month. That adds up over time. Just be sure your cable company actually stops charging you the rental fee, since they've been known to "forget" in the past.
For anyone currently using a modem/router combo unit from your ISP, we generally recommend keeping these two devices separate. That means if you wish to buy your own modem, you will also need to purchase a wireless router. Buying both devices will bring up the cost of upgrading, but you will still be better off in the long run—especially if you need a mesh Wi-Fi system.
Why Rent Your Modem
There are some benefits to renting. You can trade it in when it becomes obsolete or if it stops working. Plus, you don't have to worry about compatibility or replacing the unit yourself if something goes wrong as your ISP can just swap it out for you. And again, if your ISP includes the cost of a modem in your package pricing, you won't save any money by purchasing your own.
In addition, some ISPs may not even let you buy your own modem. If you have DSL or fiber, you can't use a cable modem; they use special equipment you have to rent or purchase from your ISP.
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 Telephony modems aren't widely available for sale—a quick search yields expensive products with outdated technology—so you're most likely better off renting.
If you aren't sure what you're allowed to do, check your ISP's website, or give customer service a call to see if it's possible to use your own modem. Most will list compatible modems on their website (here's how to check for Comcast, Cox, and Spectrum.)
DOCSIS 3.0 vs DOCSIS 3.1
Just like routers, more expensive modems provide faster speeds—as long as you have a fast enough plan with your ISP. Conversely, if you pay for a super-fast internet package but buy a cheap modem, you may not be getting those advertised speeds. So it's important to compare the modem's specs to your internet plan before you buy.
The maximum speed of your modem is dependent on the Data Over Cable Service Interface Specification (DOCSIS), a telecommunications standard used to provide internet access over a cable modem. For years, the standard has been DOCSIS 3.0, though many ISPs now require a DOCSIS 3.1 modem if you're adding a new one to your plan.
DOCSIS 3.0's highest possible speed is 1Gbps, also known as “Gigabit internet." However, DOCSIS 3.1 maxes out at a whopping 10Gbps. Most consumers won't see speeds that high right now, but in the future, they could. Some providers have offered 1Gbps plans over DOCSIS 3.0, while others now require a DOCSIS 3.1 modem. The latter is the all-around better option, so we recommend them if you're going with a gigabit plan.
DOCSIS 3.1 modems are backward compatible with DOCSIS 3.0, so even if your provider doesn't require it yet, you can use it with your plan. But they're more expensive. If your provider doesn't offer gigabit plans yet, you may not want to spring for a DOCSIS 3.1 modem, since they may end up offering gigabit speeds over fiber or another type of connection. This way you won't spend money on something you might not need in the present or near future.
If you have a slower plan and decide to go with a DOCSIS 3.0 modem, you'll want to look at one other spec: the number of downstream and upstream channels it supports. 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.
For example, 8x4 modems—that is, modems with eight downstream channels and four upstream channels—support a theoretical maximum of 343Mbps. A 16x4 modem generally tops out at around 680Mbps for downloads. However, these are just theoretical maximums—your ISP may only support certain modems up to a certain speed, so check its compatibility list before putting too much stock into the theoretical numbers.
Another factor worth considering (eventually) is DOCSIS 4.0, the newest standard that was announced in 2019. DOCSIS 4.0 promises the same 10Gbps down seen in 3.1 modems, but also 6Gbps in upstream capacity. There are currently no modems on the market that are compatible with this standard, but it's something to think about as you look to upgrade.
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 what's compatible with your ISP and your particular plan, and offers the best balance of price and features (not to mention a good warranty).
The best modems overall support DOCSIS 3.0 or 3.1, and are compatible with the major US cable companies, namely Spectrum, Comcast, and Cox, which is true of all the modems listed below. Most of these models cost $100 or less (excluding the DOCSIS 3.1 options), so if you're paying $10 a month to rent your modem, you'll make back your investment in less than a year.
DOCSIS 3.0 Modems
If you have an internet plan that is slower than 1 Gigabit, go with a DOCSIS 3.0 modem. Since you may never be able to benefit from a DOCSIS 3.1 modem anyway, you might as well save money.
Netgear CM500
Netgear's CM500 is the most affordable modem we'd recommend buying right now. This modem uses 16 downstream and four upstream channels, giving it a theoretical bandwidth of 680Mbps download and 131Mbps upload. But check what your ISP supports—Netgear advertises this as a modem for 300Mbps plans. Even if you don't have a plan that fast, the CM500 is close enough in price to older 8x4 modems that it's worth buying over slower models in case your provider increases your plan's speeds. The CM500 comes with a one-year warranty.
Arris Surfboard SB6183
Arris' Surfboard line will likely look familiar to many people. The SB6183 uses the same 16x4 channel design as the Netgear CM500 and Arris recommends it for use with 300Mbps plans or slower. At the time of this writing, it's more expensive than Netgear's offering, but if price and stock fluctuations make it a better deal, it's a good alternative. It also comes with a two-year warranty instead of Netgear's one-year warranty, so that may be worth the extra few bucks if you want the peace of mind.
Motorola MB7621
If you have a plan that goes up to 650Mbps, you'll want to step up to something with 24 upstream and eight downstream channels like the Motorola MB7621. It comes with a two-year warranty and is compatible with most ISPs. While 24x8 supports a theoretical speed of 1Gbps, it's unlikely your ISP rates this modem for those speeds, so you'll want one of the DOCSIS 3.1 modems below.
Netgear CM600
If Motorola's MB7621 is out of stock or more expensive than the Netgear CM600, the latter is worth looking at. It uses the same 24 upstream and eight downstream channels, and is compatible with most ISPs. But it only comes with a one-year warranty, which makes it our second choice for 24x8 modems.
DOCSIS 3.1 Modems
If you pay for Gigabit internet or higher, we recommend going with a DOCSIS 3.1 modem. This way you can fully benefit from the speeds your plan offers and avoid limiting your network's capabilities by using an older unit.
Motorola MB8600
If you need a DOCSIS 3.1 modem for gigabit speeds from your ISP, check out the Motorola MB8600. It's one of the least expensive DOCSIS 3.1 modems available right now, and it comes with multiple Gigabit Ethernet ports for connecting your router—plus a two-year warranty. If you're still using DOCSIS 3.0 for the time being, it supports that as well, providing 32 downstream channels and eight upstream channels for that standard.
Arris Surfboard SB8200
If the Motorola MB8600 isn't available, the Surfboard SB8200 is another fine choice for DOCSIS 3.1. Like the Motorola, it has 32x8 DOCSIS 3.0 support for backward compatibility and a two-year warranty, but it has two Ethernet ports for link aggregation.
Netgear CM1000
Netgear also makes its own DOCSIS 3.1 modem for gigabit customers, and it's similarly priced to the other two offerings, though it only comes with a one-year warranty and a single Ethernet port. If neither of the other two are an option, the Netgear CM1000 should do in a pinch.
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