Best Xfinity-Compatible Modems 2021

ARRIS S33 is the best Xfinity-approved modem to work with any download speed. But if you have a slower plan like Performance Starter or Performance Select, your internet will work fine with a cheap modem like NETGEAR CM400.

While leasing the swanky Xfinity xFi Gateway has its perks, buying an Xfinity-compatible modem is the cheaper option in the long run. Let’s save you some cash with the best modems for Xfinity from Comcast.

Jump to:

• Head-to-head comparison
• Best Xfinity-compatible modems
• What to look for
• FAQ

Best Xfinity-compatible modems

• ARRIS S33 — Best for Gigabit plan: $199.99
• Motorola MB8600 — Best for Extreme Pro plan: $149.99
• ARRIS SB6183 — Best for Blast! plan: $66.28
• NETGEAR CM400 — Best for Performance Starter & Performance Select plans: $36.95
• NETGEAR CM1150V — Best for voice plans: $188.77

*Amazon.com price as of 6/10/21 at 11:34 am PT. Read full disclaimer.

That’s the short and sweet on these Xfinity-approved modems. Now let’s take a deeper dive into each unit and the Xfinity-compatible routers that pair well with them.

Compare Xfinity-compatible modems

*Amazon.com price as of 6/10/21 at 11:34 am PT. Read full disclaimer.

Xfinity-compatible modems should have a max recommended speed that is the same or greater as your Xfinity Internet plan’s download speed. That way, your modem will deliver all the speed you’re paying for.

And if you have a home phone plan, make sure to get an Xfinity Voice–compatible modem like the NETGEAR CM1150V. Voice modems are specifically designed to support phones—a regular modem won’t cut it.

Best for Gigabit: ARRIS S33

*Amazon.com price as of 6/10/21 at 11:34 am PT. Read full disclaimer.

ARRIS S33 is our pick for the best modem for Xfinity. This absolute beaut’ from ARRIS makes our hearts go pitter-patter. It comes with the latest DOCSIS 3.1 technology, which is just what you need to get the most out of your Xfinity Gigabit plan—even with the new speed hike up to 1,200 Mbps.

But if you want to be on the cutting-edge of modem tech, it’ll cost ya. To be fair, if you’re already shelling out for Xfinity’s Gigabit plan, you’ve probably got enough cash flow that you’re not worried about the $199.99 upfront price tag in exchange for long-term savings.

As for the rest of us, we’ll stick with the bargain modems.

Get the ARRIS S33

Best for Extreme Pro: Motorola MB8600

*Amazon.com price as of 6/10/21 at 11:34 am PT. Read full disclaimer.

The Motorola MB8600 supports up to 1,000 Mbps download speed. But since Xfinity upped its Gigabit plans to 1,200 Mbps, we suggest you use it only for Xfinity’s Extreme Pro and lower-speed plans.

If you’re living in the fast lane, you’ll appreciate how smoothly this modem streams 4K Ultra HD content and handles high-speed online gaming. And it’s durable, too, so you can expect it to keep you up to speed for years to come.

Get the Motorola MB8600

Best for Blast!: ARRIS SB6183

*Amazon.com price as of 6/10/21 at 11:34 am PT. Read full disclaimer.

While the ARRIS SB6183 runs on DOCSIS 3.0 tech—older than the DOCSIS 3.1 of the two previous devices—it’s still a zippy little modem. If you have an Xfinity Blast! or Blast! Pro Plus plan, go for this device to get the speeds you need without forking out a ton of dough.

Get the ARRIS SB6183

Best for Performance Starter & Select: NETGEAR CM400

*Amazon.com price as of 6/10/21 at 11:34 am PT. Read full disclaimer.

This affordable Xfinity-compatible modem is reliable and easy to install. For a bargain modem you can set and forget, it doesn’t get better than this.

Although this modem doesn’t have the latest DOCSIS 3.1 technology, it uses DOCSIS 3.0 technology at speeds most Xfinity households will appreciate. And if that techy talk has you baffled, don’t worry. We’re just saying the NETGEAR CM400 will take good care of you and your Xfinity plan.

Your favorite writer (me) uses the NETGEAR CM400 at home when I’m not testing out the Xfinity xFi Gateway. It’ll be a perfect fit for you, too, if you use Xfinity’s Performance Starter or Performance Select plans.

Get the NETGEAR CM400

Best for voice plans: NETGEAR CM1150V

*Amazon.com price as of 6/10/21 at 11:34 am PT. Read full disclaimer.

If you’re getting a voice plan from Xfinity, the NETGEAR CM1150V will help connect your phone service as well as your internet service. Then you can call and tell all your friends about it (lol).

This modem is about as souped-up as the ARRIS S33, so it can handle Xfinity’s Gigabit plan, no sweat.

But this little baby from NETGEAR is a bit pricey, so if you’ve got a slower plan, you can save some money with another product like ARRIS SVG2482AC. This second option can handle speeds up to 600 Mbps, and it comes with a Wi-Fi router built-in too.

Get the NETGEAR CM1150V

What’s the best Wi-Fi modem for Xfinity?

We prefer using separate modems and routers here at CableTV.com because most combination modem/routers don’t come with the latest technology, and they can be scary expensive.

But if you like the convenience of having one do-it-all device, more power to you! We can help you find the modem/router combo of your dreams over at “Best Cable Modem/Router Combos.”

The bonafide Xfinity modem/router

Does all this talk about buying a modem for Xfinity have you overwhelmed? No stress. You can rent the Xfinity xFi Gateway for $14 a month instead.

There are a few models of the xFi, but Xfinity will send you one that supports your Xfinity plan download speeds and works with the internet technology in your area. It has a built-in router and telephone support, too, so you’ll be set for voice and Wi-Fi as well.

We like Xfinity’s modem/router combo. It’s easy to set up, the parental controls are great, and you’ll get Xfinity Wi-Fi hotspots (which will save you from passing out your Wi-Fi password to every internet-jonesing visitor you have).

However, the price of renting the xFi Gateway adds up. For more help deciding if this Xfinity router and modem combo is right for you, check out our full Xfinity xFi Gateway review.

What to look for in a modem

Modems are pretty simple as far as computer devices go. We’ve covered them in depth in our cable modem buyers guide, but here are the basics.

Max recommended speed

Before you purchase a modem, remember the download speeds your Xfinity plan comes with. If your modem isn’t built to support those speeds, you won’t get to enjoy all the internet speed you’re paying for.

We recommend that most people get at least 100 Mbps to enjoy streaming TV online. If you haven’t gotten your Xfinity plan yet, and you’re unsure what speeds you need, check out our article “What Is a Good Internet Speed?” for help deciding.

Channel bonding

You don’t need to know what channel bonding is to get a suitable modem, but if you’re curious, think of modem channels as lanes on a freeway. The same way more lanes can move more vehicles through at once, more channels on a modem allow more data per second, so your modem can support faster download and upload speeds.

But while more channels can access faster internet speeds (within the amount you’re paying your internet provider for), the technology for lots of channels costs more than the tech for just a few. To save money, don’t pay for a more robust modem than you need.

DOCSIS technology

DOCSIS stands for “Data Over Cable Service Interface Specification.” It’s the standard for sending a lot of data by coaxial cable at once. The latest version is DOCSIS 3.1, which Xfinity has set up in some cities, but DOCSIS 3.0 is still common.

DOCSIS 3.1 modems are backward-compatible, so if you get a DOCSIS 3.1 modem, you’re set no matter where you live. But if you want to be sure you’ll be okay with DOCSIS 3.0 in your area, check your address with Xfinity’s device webpage.

Our final take: Buy your own modem and save some cash.

While plenty of Xfinity-supported modems are out there, these five are well-suited to specific plans. Find the one that matches your package for a fantastic Xfinity experience without the monthly modem lease fees.

Our methodology

From Xfinity’s list of 83 compatible third-party modems, we researched and selected modems that will work best with your Xfinity plan according to price, specs, supported speeds, and customer reviews.

For more information about our methodologies, feel free to peruse our How We Rank page.

Xfinity modem FAQ

Can I buy my own modem for Xfinity?

Xfinity allows you to bring your own modem as long as you buy one that’s compatible with Xfinity internet service. Check our above chart of modems compatible with Xfinity to find one that works best with your Xfinity internet plan.

Does Xfinity (Comcast) sell modems?

You can rent the xFi Gateway (a modem/router combo) from Xfinity for $14 a month—but it’s cheaper long-term to purchase your own.

Should I buy my own modem and router for Xfinity?

You should buy a modem and router if you don’t want to pay $14 per month to rent a modem/router combo from Xfinity and if you’re willing to pay a lump sum upfront for savings in the long run.

The Xfinity xFi Gateway and the Xfinity app make it easy to customize your home Wi-Fi, but renting adds up over time. However, you’ll notice that high-speed modems and routers cost much more than lower-speed devices. If you have the Gigabit plan, renting from Xfinity may be more doable than paying hundreds of dollars for your own equipment.

How do I know which modem is compatible with Comcast?

1. Head over to Xfinity’s device webpage.
2. Enter your address and select your current Xfinity plan—or the one you’re planning to get.
3. Click “Find Devices.” If you get a pop-up, click “Continue to approved devices.”
4. Change any filters needed on the left side. For example, if you have an Xfinity Voice plan, be sure to click the “Voice/Telephone enabled” box. If you’d like a modem/router combo, click the “Built-in WiFi” box.
5. Xfinity lists the fastest (and most expensive) modems first, but any of the modems listed will work well with your internet plan. Under the modems that appear, click the “Show more devices” link. That will pull up all your options, making it easier to find an affordable Xfinity-compatible modem.

Which modem works best with Xfinity?

The ARRIS S33 is our recommended best modem for Xfinity. It supports download speeds up to Xfinity’s lightning-fast Gigabit plan.

But if you want to control your modem from the Xfinity mobile app, an Xfinity modem like the xFi Gateway is the right way to go. The xFi Gateway is available by directly renting from Xfinity for $14 per month.

What modem does Xfinity use?

Xfinity uses four models of its xFi Gateway (and a few sub-models). It assigns Xfinity modems to customers based on their location and service plan:

• xFi Wireless Gateway—275–700 Mbps (varies by sub-model)
• xFi Fiber Gateway—1,000 Mbps
• xFi Advanced Gateway—2,500 Mbps
• xFi Gateway 3rd Generation—1,000 Mbps

What is the newest Xfinity modem?

The newest Xfinity modem is the xFi Gateway 3rd Generation. It supports internet speeds around 700 Mbps—less than the xFi Advanced Gateway’s 1,200 Mbps.

Xfinity’s big selling point for the 3rd Generation is that it’s light gray instead of black (no, we’re not joking—Xfinity’s support article points out the color first). It also has four Gigabit Ethernet Ports to the xFi Advanced Gateway’s two.

Otherwise, we can’t see anything special about it that differentiates the 3rd Generation from Xfinity’s xFi Advanced Gateway. Newer isn’t always better, it seems.

What is the fastest internet speed for Xfinity?

Xfinity offers internet speeds up to 2,000 Mbps—but only in a few big cities. This exorbitantly expensive plan is much faster than most homes need. You’re probably better off sticking with a plan that has 1,200 Mbps speeds or slower.

See Xfinity internet plans

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