The 7 Best Cable Modems of 2021

Our experts tested the best cable modems to save you money

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Most internet service providers (ISPs) rent the cable modem you use to get on the internet (check your bill). You can buy your own cable modem and, in less than a year, come out ahead. You have to be a bit comfortable around this kind of equipment, but you do end up saving money.

If that’s something you’d like to try, you should probably just buy the get the ARRIS SURFboard SB6190 or, if you pay for a higher speed connection, the ARRIS SURFboard SB8200. Before buying, make sure your ISP is listed on the product page (most of the ISPs are represented so you are likely good to go).

The Rundown
It's small enough to be tucked away just about anywhere, and is also certified by all the major cable providers.
The Netgear Nighthawk CM2000 is the fastest cable modem you can get.
Best for Multi-Gigabit Internet:
Motorola MB8611 at Amazon
You should see the same blazing speeds as the Netgear Nighthawk CM2000, but end up with a few more bucks leftover.
This modem allows you to have two separate networks from your single connection.
It’s just as fast as the fast ones on this list, but for a lot less money.
Best for Voice Services:
Netgear Nighthawk CM1150V at Amazon
The good news is this modem does voice, high-speed connections, and allows you to have two independent networks.
Best for Basic Internet Plans:
Motorola MB7420 at Amazon
This modem should be purchased only if you know you aren’t going to get a higher-speed connection and your needs are pretty modest.

Best Overall: Arris Surfboard SB6190 DOCSIS 3.0 32x8 Cable Modem

ARRIS SURFboard SB6183 DOCSIS 3.0 Cable Modem
What We Like
  • Impressive speeds

  • Great for HD movies and gaming

  • Convenient LED indicator lights

What We Don't Like
  • Coaxial connection placement isn't ideal

A successor to Arris’ extremely popular SB6183, the SB6190 continues the company’s reputation for making some of the most reliable cable modems available. If you have a regular internet connection less than 1Gbps (which is what most of us have), the Arris Surfboard SB6190 will fit your needs just fine. There’s a really good chance you’ll take this out of the box, swap it with the modem from your cable company and not even think about the modem ever again.

It's small enough to be tucked away just about anywhere, and is also certified by all the major cable providers, so you shouldn't have a problem getting it running with your internet service provider of choice.

DOCSIS Standard: 3.0 | Channels: 32x8 | Speed: 1.2Gbps / 216Mbps | Voice Support: No | MOCA: No | Wired Ports: 1

Best Performance: Netgear Nighthawk CM2000 DOCSIS 3.1 Cable Modem

Netgear Nighthawk CM2000 DOCSIS 3.1 Cable Modem
What We Like
  • 2.5Gbps Ethernet Port

  • Fast DOCSIS 3.1 Speeds

  • Sleek design

What We Don't Like
  • Pricey

  • Requires compatible router for best speeds

  • No voice capabilities

If you want the best performance and cost is no object, the Netgear Nighthawk CM2000 is the fastest cable modem you can get. Keep in mind, in order to take advantage of this performance, you need a high-speed connection from your ISP and a router capable of sending information to your other devices at the fastest speed possible.

DOCSIS Standard: 3.1 | Channels: 2x2 / 32x8 | Speed: 2.5Gbps / 800Mbps | Voice Support: No | MOCA: No | Wired Ports: 1 (2.5Gbps Ethernet)

Best for Multi-Gigabit Internet: Motorola MB8611 DOCSIS 3.1 Cable Modem

Motorola MB8611 DOCSIS 3.1 Cable Modem
What We Like
  • 2.5Gbps Ethernet Port

  • Fast DOCSIS 3.1 Speeds

  • Low Latency

What We Don't Like
  • Pricey

  • No voice capabilities

  • Requires compatible router for best speeds

If you want the best possible performance, but every nickel counts, the Motorola MB8611 is a good choice. You should see the same blazing speeds as the Netgear Nighthawk CM2000, but end up with a few more bucks leftover.

Now, the same caveats apply: You need a really fast connection and a router capable of sending that fast connection to the devices on your network.

DOCSIS Standard: 3.1 | Channels: 2x2 / 32x8 | Speed: 2.5Gbps / 800Mbps | Voice Support: No | MOCA: No | Wired Ports: 1 (2.5Gbps Ethernet)

Best Design: Arris Surfboard S33 DOCSIS 3.1 Cable Modem

Arris Surfboard S33 DOCSIS 3.1 Cable Modem
What We Like
  • Stylish design

  • 2.5Gbps Ethernet Port

  • Extra Gigabit Ethernet Port

What We Don't Like
  • No voice capabilities

  • Use of second port isn't supported by all ISPs

There’s a lot of brains behind this beauty: Not only is this a fast modem, not only is this a modem you don’t need to hide in a closet (although we still would), this modem also allows you to have two separate networks from your single connection.

That’s pretty neat, although we don’t know anyone who might need such a feature. The price of the Arris Surfboard S33 is also quite good, considering its bevy of features.

DOCSIS Standard: 3.1 | Channels: 2x2 / 32x8 | Speed: 2.5Gbps / 800Mbps | Voice Support: No | MOCA: No | Wired Ports: 2 (2.5 Gbps / 1 Gbps Ethernet)

Best Value: Arris Surfboard SB8200 DOCSIS 3.1 Cable Modem

Arris Surfboard SB8200
What We Like
  • High speed support (known as DOCSIS 3.1 Support)

  • Compact design

  • Two Gigabit Ethernet ports with link aggregation

What We Don't Like
  • Pricey

  • Awkward coaxial connection placement

We have arrived at the best bang-for-your-buck winner, high-speed category: Arris Surfboard SB8200. It’s fast as heck at a very good price. If you are about to upgrade to a faster internet connection, this is the one to get.

It’s just as fast as the fast ones on this list, but for a lot less money. It’s your money, so spend it how you wish, but we know we wouldn’t spend more for something that isn’t demonstrably better.

DOCSIS Standard: 3.1 | Channels: 2x2 / 32x8 | Speed: 2Gbps / 800Mbps | Voice Support: No | MOCA: No | Wired Ports: 2

"Although there are DOCSIS 3.0 cable modems that technically support speeds of 1Gbps or higher, chances are that your cable internet provider will cap out at 600Mbps over DOCSIS 3.0. If you want real gigabit fibre-optic class speeds you'll need to invest in a DOCSIS 3.1 cable modem." — Jesse Hollington, Tech Writer

Best for Voice Services: Netgear Nighthawk Nighthawk CM1150V DOCSIS 3.1 Cable Modem with Voice

Netgear Nighthawk CM1150V
What We Like
  • High speed support

  • Up to 2Gbps Download Speeds

  • Supports Xfinity Voice service

What We Don't Like
  • Expensive

  • Not compatible with other cable voice services

This is the modem to get if you are also using landline telephone service from your ISP. It's an expensive modem, but you are likely already paying a fair bit of money for a lot of service, so you can’t use any regular modem.

The good news is this modem does voice, high-speed connections, and allows you to have two independent networks. For what you get, it’s a lot. But you need this only if you are doing telephone service.

DOCSIS Standard: 3.1 | Channels: 2x2 / 32x8 | Speed: 2Gbps / 800Mbps | Voice Support: Yes | MOCA: No | Wired Ports: 4 (Ethernet) / 2 (Telephone)

Best for Basic Internet Plans: Motorola MB7420 DOCSIS 3.0 16x4 Cable Modem

Motorola MB7420 DOCSIS 3.0 Cable Modem
What We Like
  • Very affordable

  • Compact

What We Don't Like
  • Not especially future-proof

This modem should be purchased only if you know you aren’t going to get a higher-speed connection and your needs are pretty modest. If that’s you, this modem should pay for itself in under a year.

Now, before the word "modest" scares you away, you can still stream in 4K, use the internet like normal, and do plenty of video calls. It should meet all your needs without having to spend a lot of money.

DOCSIS Standard: 3.0 | Channels: 16x8 | Speed: 606Mbps / 108Mbps | Voice Support: No | MOCA: No | Wired Ports:

Final Verdict

The Arris Surfboard SB6190 (view at Best Buy) offers the best balance of price, performance, and size for most cable internet subscribers, but to break past the high-speed (1Gbps) speed barrier you'll need a high-performance modem like the ARRIS SURFboard SB8200 (view at Amazon). They are both fairly priced and perform very well.

FAQ
  • What’s the difference between DOCSIS 3.0 and DOCSIS 3.1?

    DOCSIS, which is a short form for “Data Over Cable Service Interface Specification,” is the technology on which all cable modems are based. DOCSIS 3.0 is the standard currently being used by almost all cable providers, but even though it offers theoretical speeds of up to 1Gbps, most ISPs in the U.S. don’t go beyond 600Mbps over DOCSIS 3.0. That means that to get true multi-gigabit plans, you’ll need a DOCSIS 3.1 cable modem. Don’t worry if your ISP doesn’t support the newer standard yet, though, as all DOCSIS 3.1 modems are fully backward compatible with DOCSIS 3.0, so you can buy one now to be ready when those faster speeds do come along.

  • What happens if your cable modem breaks down?

    While it’s true that one of the advantages of renting your cable modem from your ISP is they’ll easily swap it out if you have any problems—something that won’t be an option if you’ve bought your own—the reality is that modern cable modems are very reliable as long as you go with a trusted brand, and almost all of them also come with 1–2 year warranties. 

  • What about cable modem/router combos?

    If you’re in the market for a new wireless router anyway, then it might be worth considering one of the best cable modem/router combos instead, since you’ll get the best of both worlds in a much more affordable package. There’s rarely any good reason to go that route if you’re perfectly happy with the Wi-Fi router that you already have, though, as any cable modem should work just fine with any relatively modern router. 

  • What are download channels?

    The DOCSIS standard isn’t the only thing that determines the speeds you can achieve with your modem. The number of download and upload channels is the other big factor to consider.

    Download and upload channels are expressed as two numbers separated by an “x”, where the first number is the number of download channels and the second number the number of upload channels. So, for example, a 16x4 modem has 16 download channels and four upload channels.

    It’s important to note, however, that just because you have a modem that theoretically supports up to 688Mbps (on a modem with 16 downstream channels), that doesn’t mean that you’ll achieve that speed. You might only be subscribed to a data plan from your ISP that offers up to 100Mbps, in which case that’s the maximum you’ll get from your modem—if you even reach that.

    There are also other factors to consider like communication overhead and shared bandwidth with other users in your neighbourhood. As a rule, you'll find that most ISPs provide considerably slower speeds for any given channel configuration. Always check to see what a modem is "certified for" by a given provider to get an idea of what speeds to expect.

  • What's a good download speed?

    So what’s a good download speed? Well, it really depends on your usage, but more is better. While the average download speed in the United States is 64.17Mbps, that number is likely to rise in the near future as ISPs roll out Gigabit internet speeds. Because of that, we recommend getting a modem that has at least a 1Gbps download speed. It means you’ll be ready for faster internet once it rolls out. So what do those speeds mean? Well, to download a Full HD movie with a file size of 4.5 GB, it’ll take 4 minutes to download a movie with a 50Mbps download speed, and 2 minutes on a 100Mbps download speed. With a 1Gbps download speed, it’ll take 12 seconds.


  • What internet speed should you buy?

    With more people streaming using services like Netflix and Disney+, fast download speeds aren't nearly as important as they once were, since you're watching a movie in real-time—in other words, it doesn't matter if a movie takes an hour to download if it's going to take you two hours to actually watch it.

    Streaming speeds are therefore measured using the same numbers as your internet speed, and even a full 4K UHD stream on Netflix only requires a 25Mbps connection to maintain. Of course, if you have multiple users streaming in 4K in different rooms, they'll each need their own 25Mbps slice of your bandwidth, not to mention other activities like surfing, gaming, downloading, and video calling which all use various amounts of bandwidth. This can add up quickly if you have a large family or a lot of roommates sharing your internet connection.

What to Look For in a Cable Modem

The world is becoming increasingly connected, and it’s more important than ever to make sure that you have a decent connection in your home. Not only does that mean ensuring you’re subscribed to a fast internet service, but that you also have the right hardware to provide a fast and stable connection whenever you need it.

There are two main components to a home internet network: a modem and a router. The modem is what converts a cable signal from your internet service provider (ISP) into something that a digital device like a computer can understand. The router then takes that signal and distributes it to the computers and other connected devices in your home, either via wired Ethernet connections or by beaming it out over Wi-Fi, which is how you get wireless internet connectivity in your home.

Of course, there are a ton of things to consider when buying a modem. You don’t always need to buy a modem, as you can typically rent one directly from your ISP, although if you do the math you'll likely find it makes more financial sense to buy your own. Then, you’ll need to think about whether you want a modem/router combo and what features you want from your modem—including what modern connection protocols it supports, the number of channels that it offers, and how quickly it can upload and download files.

Whether you think you know everything you need to or you’re starting from scratch, here are all the features you should keep in mind while buying a modem.

Motorola MG7700

When Should You Rent Your Cable Modem?

Before diving into the features to consider when buying a modem, it’s worth considering the possibility that you could simply rent one from your ISP. The modems on offer by ISPs are generally decent in quality (though not as good as the modems you can buy), plus going with a rental saves you from doing the legwork of finding one on your own. Further, in the unlikely event that anything goes wrong with your cable modem, your ISP will take responsibility for fixing or replacing it, often even sending a technician to your home to take care of everything for you.

Netgear-Nighthawk C7000

Generally, though, we recommend against renting a modem from your ISP. Since the rental often comes out to between $10 and $15 per month, you can save quite a bit of money by purchasing your own. For example, if you bought a modem/router combo for just $75, you can easily recoup your costs in less than a year.

That doesn’t mean that there aren’t situations in which you should rent a modem. For starters, if you’re not very tech-savvy or don’t like having to troubleshoot problems, then renting a modem may be the way to go, as you’ll often get full repair services from your ISP.

For most, we recommend buying your own modem. You’ll get much more control over your home network, and after a few years, you’ll have recouped the cost of the devices that you would have otherwise had to rent. There's no need to worry about hardware problems either, since not only are they pretty rare among the more well-known brands, but they all come with a standard warranty too.

Compatibility with Your ISP

There are other advantages to buying your own modem. For starters, the modems that you can rent from your ISP are usually on the older side, and may not offer as fast or as stable of a connection as you could get with something more modern. Most of the time, ISP modems lack features, and they prevent you from getting much control over your home network, which might be important if you want to tweak your network’s settings.

Before buying a modem, it’s worth double-checking that the modem you’re interested in is compatible with your ISP. Unfortunately, not all modems are supported by every ISP. Most ISPs will have a list of compatible modems on their website, or, at the very least, you should be able to contact customer service to find out.

If you subscribe to voice services from your ISP, such as Xfinity from Comcast Internet with Voice, you'll also need to make sure that the cable modem you purchase supports your provider's voice services. While it's theoretically possible to run your old voice-capable cable modem in parallel with a newer, high-performance modem, this can get messy and it's not supported in every case. Besides, the main point of buying a cable modem is so you don't have to keep paying rental fees for the old one.

Motorola MG7700 combo

About Our Trusted Experts

Jesse Hollington is a freelance writer with over 10 years of experience writing about technology and three decades of experience in information technology and networking. He's installed, tested, and configured just about every type and brand of router, firewall, wireless access point, and network extender in places ranging from single-family dwellings to office buildings.

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