What cable modem should I buy?
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Summary
You only need a cable modem if your internet comes in through a cable TV-style coaxial connection
If you're going to buy one, I recommend the Netgear Nighthawk CM3000 (MSRP: $299.99), it supports the Next Gen speeds Comcast is rolling out and should last a decade
If you have a telephone/voice plan through your cable company, rent a modem from them instead
If you're not sure what you have or what you need, I can help
Note: this recommendation is for people with residential accounts. Cable companies may have additional requirements for business accounts, particularly for those with telephone service. Check with their customer service to confirm compatibility with your plan.
| ★ My recommendation Netgear Nighthawk CM3000 |
|
|---|---|
| Where to buy | |
| Maximum speed | 2.5 Gb down / 1 Gb up* |
| Xfinity Next Gen speed | ✅ |
| DOCSIS | 3.1 |
| Supports telephone service | ❌ |
| Supports gigabit internet | ✅ |
| Works with | Xfinity, Cox, Spectrum, and other major cable providers |
*Actual upload speeds depend on your cable provider, plan, and whether your neighborhood has been upgraded to Next Gen infrastructure.
If this is the cable that brings you internet, you have cable.
Do I have or need a cable modem?
There are many methods by which people get internet service in their homes. Most commonly it's:
fiber (Verizon FiOS, AT&T, Sonic),
wireless (Monkeybrains, T-Mobile Home Internet, Verizon Wireless),
satellite (Starlink, HughesNet, ViaSat), or
cable (Comcast Xfinity, Astound, Spectrum, Cox, Optimum)
You only need a cable modem if you have cable internet service. Basically, if your internet comes in through a thick, round screw-in TV cable (as shown in my header image above), you need a cable modem. This can be one you buy yourself or one provided by the cable company.
Should I rent or buy a cable modem?
You have the choice to either own or rent a modem. There are advantages and disadvantages either way. Generally, owning is better for larger homes (over 1,800 square feet) because you are likely going to need a mesh WiFi system (see my home WiFi recommendations), and for those who need the best possible connection. Renting is sometimes better for small homes or apartments and for those with basic internet needs.
| Own | Rent | |
|---|---|---|
| Price | MSRP: $299.99 one time | $15–25/month |
| Best for | People who want the best possible hardware | People who want the easiest setup |
| Customer service | The cable company charges extra for service calls that turn out to be caused by your own modem | Included |
| Replacements (failures or upgrades) | Your expense | Included |
| WiFi | Can be included but I usually recommend devices that are separate | Included |
| Mesh WiFi for larger homes | More flexibility with a WiFi system that is likely better than what the cable company provides | Usually a single option that is pretty lousy, but a few small internet providers use Eero |
| Speed | Higher-end modems can often get faster speeds, and faster ping times in particular. Usually better for people who need the absolute best connection. | Usually good, but rarely excellent. Usually good enough for people who do basic work from home and join video calls. |
| Data limits (Xfinity) | Generally limited to 1.2 TB/month, but that's usually enough for all but the heaviest users. You can often switch to unlimited for a fee. | Depending on your plan you may not have a limit |
| Parental controls (Xfinity) | Dependent on your router | Included |
Why the Netgear Nighthawk CM3000?
I recommend the Netgear Nighthawk CM3000. It uses mid/high-split DOCSIS 3.1 technology, which means it's built to handle the "Next Gen" speed upgrades that Comcast is currently rolling out in many markets, including significantly faster upload speeds than older modems can deliver. It also works with other major cable providers, including Cox and Spectrum.
Since buying a modem is a long-term investment, it's worth getting one that won't need to be replaced when your provider upgrades their network. The CM3000 is built to handle whatever speed tiers your cable company offers over the next decade. Last updated: May 10, 2026.
One exception: if you have a telephone/voice plan through your cable company, I recommend renting a modem from them instead. The pool of compatible voice modems is small, and for most people, renting is the path of least resistance in that situation.
Before purchasing, confirm this modem is compatible with your provider and plan. Xfinity customers can use this easy online tool to check.
How do I install a cable modem?
To install the cable modem yourself if you have Comcast Xfinity service, you will need to use the Xfinity app on your iPhone. Log into your account in the app, tap the person icon in the upper left corner, and then tap Activate xFi Gateway or Modem. Follow the prompts from there. The MAC address they ask for is located on the modem and the product packaging. Any 0's are zeros and 1's are ones.
If you have a provider other than Comcast, you may need to call customer service to provide your new modem's MAC address over the phone.
Further reading
If you're not sure whether you need a modem at all, or want help figuring out the right setup for your home, I'm happy to help. I offer one-on-one tech sessions in San Francisco and Washington DC, as well as Zoom sessions from anywhere. Book an appointment here.
