Motorola MB7621 Review

Motorola MB7621

Our Verdict


The Motorola MB7621 is a DOCSIS 3.0 cable modem that works with most ISPs, including Cox, Spectrum, Xfinity, and more

The MB7621 is simple to set up and supports Internet plans up to 900 Mbps or slower. It is a good choice for homes with faster Internet plans that want an affordable modem option.

However, it isn’t the most advanced modem and won’t future-proof your network.













At Networks Hardware, we routinely test various modems – so we are confident when we say the MB7621 is a great mid-tier modem. 

It is affordable, easy to set up, works with most ISPs, and is great for Internet plans up to 900 Mbps

But if you have a faster Internet plan or want to better future-proof your home network, you might want to get a different modem. 

Motorola MB7621 Overview

Motorola MB7621 Overview

The Motorola MB7621 is a DOCSIS 3.0 cable modem, which means you will have to pair it with a router if you want to connect more than one device to the Internet and create a Wi-Fi network. 

The MB7621 is only compatible with these major ISPs: Comcast Xfinity, Cox, Charter Spectrum, BrightHouse, RCN, Suddenlink, and Sparklight (CableOne). 

If you have Internet plans from any of these providers, the MB7621 is a better option than renting a modem from them. 

The only major downside of the MB7621 is that it only supports DOCSIS 3.0 and not DOCSIS 3.1.

DOCSIS 3.0 is ideal for plans less than 200 Mbps. But if you want to save money, you can also use it for faster plans.

However, you won’t be future-proofing your home network and will miss out on some security upgrades. See our guide on DOCSIS 3.0 and 3.1 for more details. 

If you plan on getting a faster Internet plan in the next few years or want the latest and greatest technology, choose a DOCSIS 3.1 modem. See our guide on the top DOCSIS 3.1 modems for our recommendations. 

Otherwise, the MB7621 is a solid choice that will save you money. 


TypeCable Modem
Wi-FiNo Router
StandardsDOCSIS 3.0 24×4 channels
Top WAN speed1 Gigabit Ethernet
Ports1 Gigabit Ethernet LAN Port and 1 Coax Port 
Top internet plan supported.900 Mbps
Supported ISP’sComcast Xfinity, Cox, Charter Spectrum, BrightHouse, RCN, Suddenlink, and Sparklight (CableOne)
Not supported ISPsAT&T, CenturyLink, Verizon, and other fiber optic, satellite, or DSL services.
Weight16.3 ounces
Dimensions7.25 x 2.25 x 7.88 inches
To learn more about the MB7621, read its full datasheet

Performance 4.4

The MB7621 has excellent performance for a DOCSIS 3.0 24×8 channels cable modem. However, a DOCSIS 3.1 modem would work better with faster Internet plans since it can provide more bandwidth– even with the MB7621’s 24×8 channels (which gives it more bandwidth).

Still, if you have a 900 Mbps Internet plan or slower, the MB7621 will provide your home with the Internet experience you need. But, if you plan to upgrade your Internet plan soon or want to future-proof your network, you should consider a DOCSIS 3.1 modem instead. 

Using the MB7621 with Internet plans faster than 900 Mbps will slow your performance, and you’ll never achieve the speed you pay for. However, using it with plans 900 Mbps or slower will give you a great home network. 

Design 4.5

Overall, the MB7621’s design is excellent. It has a modern, black design with rounded corners that will blend right into most homes. 

Motorola MB7621 Overview 2

It isn’t overbearingly large either– it has a footprint of just 7.25 inches deep and 2.25 inches wide. 

So you won’t have to rearrange your desk or shelf to find space for it. 

Motorola MB7621 Side

On the modem’s backside, you’ll find these connections and buttons:

  • On/Off button
  • Power connection
  • Coax cable connection
  • Reset button 
  • Gigabit Ethernet LAN port

On its front side, you’ll see the familiar Motorola “M” logo with the status indication LEDs below it. You can use these LEDs to verify power, downstream, upstream, Internet, and LAN connection. 

Compatibility 3.5

The Motorola MB7621 works with just a few major ISPs. This can make it difficult to determine if it will work with your provider, so double-check compatibility before buying it. 

Here are the major ISPs that are verified to work with the MB7621. With that said, some smaller or regional ISPs could be compatible too. 

Approved for:

  • Comcast Xfinity
  • Cox
  • Charter Spectrum
  • BrightHouse
  • RCN
  • Suddenlink
  • Sparklight (CableOne)

Don’t work on: 

  • CenturyLink
  • Verizon
  • AT&T
  • Satellite Internet
  • DSL services
  • Fiber optic

Setup 4.8

Like many Motorola modems, the MB7621 has a fast and easy setup. It should only take you about five minutes to set it up unless you’re attempting to use it with an incompatible ISP. 

To get the MB7621 going, just connect the coaxial cable from your ISP to its back, connect the power cord, and connect it to your router with an Ethernet cable. The MB7621 will boot up, and you should have Internet access in just a few minutes. 

What the Motorola MB7621 comes with

Connect to your network with any device and open a web browser. Sometimes, a self-activation portal from your ISP will load. In that case, follow the steps to get your Internet setup. 

Otherwise, if the Internet loads normally, you can start browsing and streaming on all your devices. 

But, if you have any issues, contact your ISP. You might need to have them remotely activate your coaxial connection. 

Suppose you want to change your modem’s settings after you set it up. In that case, you can type into any web browser to configure them.

Value 4.6

The MB7621 has a reasonable value, but it isn’t the most affordable. Sure, it costs less than a comparable DOCSIS 3.1 cable modem. 

But you’re limiting your home network and not future-proofing it with a DOCSIS 3.0 device. And even though the MB7621 has a max speed of 900 Mbps, it could limit you from upgrading your Internet plan to a faster speed. 

If you did want to upgrade your Internet plan to a 1,000 Mbps plan or faster, you’d have to get a new DOCSIS 3.1 modem. This would cost you more in the long run. 

Still, if your Internet plan is 900 Mbps or less, and you won’t be upgrading your plan anytime in the near future, the MB7621 is a great deal. 

Motorola MB7621 Reviews

The Motorola MB7621 DOCSIS 3.0 cable modem has tens of thousands of positive reviews on various consumer websites.

Most reviewers comment on its quick setup, ease of use, and good compatibility with their ISP. Many also praised its longevity– with many purchasers noting it has lasted them multiple years. 

Some of the few critical reviews complain about it not being compatible with their ISP (see our “approved for” list above if you’re worried about this). 

Still, most reviewers had a great experience with no problems. But if you run into an issue, Motorola provides a generous two-year warranty to keep you covered. 


Here are some great alternative options to the MB7621. 

Motorola MB8611

Motorola MB8611

Suppose you want to future-proof your home network and don’t want to worry about upgrading your modem when you bump up to a faster Internet plan. In that case, the Motorola MB8611 should be your top choice. 

It is a DOCSIS 3.1 cable modem that supports Internet plans up to 2,500 Mbps. So, if you have a 900 Mbps or slower Internet plan right now and might have a faster Internet plan available in your area soon. Then this modem will fully support your home network when you upgrade. 

The MB8611 is fast, competitively priced, and comes with a 2-year warranty. 

Netgear CM1000

Netgear CM1000

If you want a slightly faster modem that supports DOCSIS 3.1, the Netgear CM1000 is a good alternative. It’s best for homes with Internet plans of 1,000 Mbps or less. 

This modem will better future-proof your home network, but you’ll pay more for it. However, it is compatible with most major cable Internet providers.

It is easy to set up and has thousands of positive ratings. 

Motorola MB7220

Motorola MB7220

Perhaps the MB7621 is too expensive, or you have an Internet plan slower than 150 Mbps. In that case, the Motorola MB7220 is a good choice. 

It is a DOCSIS 3.0 cable modem too, but it only has 8×4 channels (so it is not as fast). It works with a few major ISPs – Xfinity, Cox, and Spectrum. 

And it is incompatible with the same ISPs as the MB7621. 

It is easy to set up, has a small form factor, and will work perfectly with slow Internet plans. 

Bottom Line

The Motorola MB7621 DOCSIS 3.0 cable modem is a reliable unit for Internet plans of 900 Mbps or slower. 

It is a good option if you want something affordable and don’t plan to upgrade to a faster plan anytime soon. 

It is simple to set up and is one of the most affordable modems you’ll find. 

However, since it is a DOCSIS 3.0 modem, it won’t future-proof your home network like a DOCSIS 3.1 modem would. So, if you want to give yourself the flexibility to upgrade your Internet plan in the near future, a DOCSIS 3.1 modem would be a better choice. 

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