Look at your cable bill and you will probably find an equipment fee for a modem you will never own. So after a couple of years, you have paid for that modem several times over. A good modem of your own usually ends that charge, and the best cable modem under $300 can also be faster than the box your provider rented you.
The catch, however, is that cable modems are picky. Your provider has to approve the exact model, while the ports have to match your plan. I went through the DOCSIS 3.1 models that turn up most on Xfinity, Spectrum and Cox lists and narrowed them down to seven: five modem-only picks for people who already own a router, and two combos for people who want one box.
Key Takeaways
- Best for most people: the ARRIS SURFboard S34, with a 2.5 Gbps port and support for faster upload plans.
- On a 1 Gbps plan or slower: the ARRIS SB8200 is enough and costs less.
- Want one box: the ARRIS G36 combo, with WiFi 6 built in.
- Before anything else: check that the model is on your provider’s approved list.
- Have fiber? You do not need a cable modem at all.
Disclosure: This post contains affiliate links. If you buy through them, we may earn a commission at no extra cost to you.
How we chose these modems
- We started from the DOCSIS 3.1 modems that show up on Xfinity, Spectrum and Cox lists in 2026.
- Then we checked each model’s ports, upload support and provider status against the maker’s spec pages and the providers’ own lists.
- Finally, we kept seven that cover every plan speed from basic to multi-gig, and left out older DOCSIS 3.0 models.
- We did not lab-test these modems. Where sources disagree, we say so, and every source is listed at the end.
Last updated: October 19, 2026
Before You Buy: 3 Quick Checks
- Is it on your provider’s approved list? Xfinity, Spectrum and Cox each publish one. A modem that is not on it will plug in fine and then refuse to activate.
- Does the port match your plan? A Gigabit port tops out around 940 Mbps in practice. On a faster plan you need a 2.5 Gbps port on the modem and on your router.
- Do you have a home phone through your cable company? None of these modems have phone ports, so you would need to keep the provider’s voice modem.
All 7 Modems Compared
Prices change week to week, so I use tiers: $ is the cheapest and $$$ is close to $300. Every pick is DOCSIS 3.1.
| Model | Type | Ethernet ports | WiFi | Price | Best for |
|---|---|---|---|---|---|
| ARRIS S34 | Modem | 2.5 Gbps + Gigabit | No | $$ | Most cable plans, fast uploads |
| Motorola MB8611 | Modem | 2.5 Gbps | No | $$ | Gaming, video calls |
| NETGEAR CM3000 | Modem | 2.5 Gbps + 2x Gigabit | No | $$$ | Multi-gig plans |
| Hitron CODA56 | Modem | 2.5 Gbps | No | $ | Multi-gig on a budget |
| ARRIS SB8200 | Modem | 2x Gigabit | No | $ | Plans up to 1 Gbps |
| ARRIS G36 | Combo | 2.5 Gbps + Gigabit LAN | WiFi 6, AX3000 | $$$ | One box for most homes |
| NETGEAR CAX30 | Combo | 4x Gigabit LAN | WiFi 6, AX2700 | $$$ | Apartments |
Which Modem Works With Your Provider?
Here is how each pick lines up with the three biggest cable providers as of October 2026. A ✔ means the model is on the provider’s list or the maker names that provider as tested, while “Check” means we could not confirm it, so look it up before you order. Providers change these lists several times a year, so a quick check on the Xfinity list or the Spectrum list is always worth it.
| Model | Xfinity | Spectrum | Cox | Xfinity next-gen upload |
|---|---|---|---|---|
| ARRIS S34 | ✔ | ✔ | ✔ | Yes |
| Motorola MB8611 | ✔ | Check | ✔ | No |
| NETGEAR CM3000 | ✔ | ✔ | ✔ | Yes |
| Hitron CODA56 | ✔ | ✔ | ✔ | Check |
| ARRIS SB8200 | ✔ | ✔ | ✔ | No |
| ARRIS G36 | ✔ | ✔ | ✔ | Check |
| NETGEAR CAX30 | ✔ up to 800 Mbps | ✔ | ✔ | Check |
“Next-gen upload” refers to Xfinity’s newer plans with much faster uploads. They need a modem that supports the newer upstream split, so if you are not on one of those plans, this column does not matter to you.
The 7 Best Cable Modems Under $300
1. ARRIS SURFboard S34: Best Overall
BEST OVERALL
ARRIS SURFboard S34 DOCSIS 3.1 Multi-Gig Cable Modem
✔ 2.5 Gbps port ✔ Next-gen upload ready ✔ 2-year warranty
If you asked me to pick one modem for a cable home without knowing anything else, it would be the S34. ARRIS also says it is tested with Xfinity, Spectrum and Cox. The 2.5 Gbps port means it will not hold you back if you move to a plan over 1 Gbps, and the extra Gigabit port is there if you ever want to plug a second device straight into the modem.
However, the real reason to buy it over the older S33 is upload speed. Cable companies are starting to sell plans with much faster uploads, and those need a modem that can switch its upstream frequencies. The S34 can, so if you do a lot of video calls, cloud backups or streaming, that matters.
WHAT WE LIKE
✓ 2.5 Gbps and Gigabit ports
✓ Ready for faster upload plans
✓ Approved by the big three cable providers
WATCH OUT FOR
✕ No phone ports
✕ Faster uploads depend on your plan
Skip it if: your plan is 1 Gbps or slower and will stay that way. The SB8200 costs less and is still plenty.
2. Motorola MB8611: Best for Gaming and Video Calls
BEST FOR GAMING
Motorola MB8611 DOCSIS 3.1 Multi-Gig Cable Modem
✔ Active Queue Management ✔ 2.5 Gbps port ✔ Xfinity, Spectrum, Cox
On download speed the MB8611 matches the S34. What it adds, though, is Active Queue Management. When someone in the house starts a big download, data can pile up inside a modem and your ping jumps. AQM keeps that queue short, which is exactly what you want in the middle of a match or a work call.
It has only one Ethernet port, though that is all most homes use. Stock has been patchy, and Amazon now shows the Motorola B12 as its replacement, so check the listing before you count on it.
WHAT WE LIKE
✓ AQM for steadier ping
✓ 2.5 Gbps port
✓ Widely approved
WATCH OUT FOR
✕ Single Ethernet port
✕ Availability varies
Skip it if: you are on an Xfinity plan with the newer fast uploads. The S34 is the safer match there because it supports those plans.
3. NETGEAR Nighthawk CM3000: Best for Multi-Gig Plans
BEST FOR MULTI-GIG
NETGEAR Nighthawk CM3000 2.5G Cable Modem
✔ 3 Ethernet ports ✔ Link aggregation ✔ Up to 1 Gbps upload
The CM3000 has more flexible ports than any other pick here, and that solves a real problem. If your router has a multi-gig internet port, use the 2.5 Gbps port. If your router only has Gigabit ports but supports link aggregation, you can combine the CM3000’s two Gigabit ports and get close to 2 Gbps without buying a new router. As a result, people on 1.2 to 2 Gbps cable plans can skip a second purchase.
It sits at the top of our price range, and it does not support Xfinity Voice, so it only makes sense if you will use the extra speed.
WHAT WE LIKE
✓ Three Ethernet ports
✓ Link aggregation for Gigabit-only routers
✓ Supports faster upload plans
WATCH OUT FOR
✕ Most expensive modem-only pick
✕ No Xfinity Voice support
Skip it if: your plan is 1 Gbps or less. Otherwise, you would be paying for ports you never use.
4. Hitron CODA56: Best Value Multi-Gig Modem
BEST VALUE
Hitron CODA56 DOCSIS 3.1 Multi-Gig Cable Modem
✔ 2.5 Gbps port ✔ Lowest multi-gig price ✔ Simple setup
The CODA56 is the cheapest way to get a 2.5 Gbps port on a cable modem, often for noticeably less than the ARRIS and Motorola multi-gig models. Still, it is a plain, single-port modem that does one job. Reviewers disagree on how well it suits Xfinity’s newest upload tiers, so this is the one pick where I would look it up on your provider’s approved list before ordering.
WHAT WE LIKE
✓ Lowest-cost multi-gig modem
✓ Simple setup
WATCH OUT FOR
✕ Single port
✕ Mixed reports on Xfinity’s newest upload tiers
Skip it if: you want the safest choice for Xfinity. Get the S34.
5. ARRIS SURFboard SB8200: Best for Plans up to 1 Gbps
BEST FOR 1 GBPS PLANS
ARRIS SURFboard SB8200 DOCSIS 3.1 Cable Modem
✔ Long track record ✔ 2x Gigabit ports ✔ Lower price
The SB8200 has been one of the most common DOCSIS 3.1 modems for years, and on a plan of 1 Gbps or less it is still the sensible buy. It has two Gigabit ports that can be combined with link aggregation, though most people plug one cable in and never think about it again. You give up the 2.5 Gbps port and the newest upload support, but you save money.
WHAT WE LIKE
✓ Proven and widely approved
✓ Lower price
WATCH OUT FOR
✕ No 2.5 Gbps port
✕ Not built for the newest fast-upload plans
Skip it if: you expect to upgrade past 1 Gbps in the next few years. The S34 or CODA56 will last longer.
6. ARRIS SURFboard G36: Best Modem-Router Combo
BEST COMBO
ARRIS SURFboard G36 DOCSIS 3.1 WiFi 6 Modem Router
✔ WiFi 6 AX3000 ✔ 2.5 Gbps port ✔ About 2,500 sq ft
If you would rather have one box on the shelf than two, the G36 puts a DOCSIS 3.1 modem and a WiFi 6 router together. It also replaces the gateway most providers rent out, with one power plug and fewer cables. The 2.5 Gbps port is handy for a fast desktop or a NAS. Note that ARRIS approves the G36 for plans up to about 1.2 Gbps, so on a 2 Gbps plan a separate multi-gig modem and router is the better setup.
The trade-off with any combo shows up later: when you want newer WiFi, you replace the whole unit instead of just the router.
WHAT WE LIKE
✓ One device to set up
✓ WiFi 6 and a 2.5 Gbps port
WATCH OUT FOR
✕ Cannot upgrade the WiFi on its own
✕ One unit may not cover a large home
Skip it if: you already own a router you like. A modem-only pick costs less than a combo.
7. NETGEAR Nighthawk CAX30: Best Combo for Apartments
BEST FOR APARTMENTS
NETGEAR Nighthawk CAX30 WiFi 6 Cable Modem Router
✔ 4 Gigabit LAN ports ✔ WiFi 6 AX2700 ✔ Nighthawk app
The CAX30, on the other hand, is the combo I would put in an apartment or a smaller home. Four Gigabit LAN ports give you room to wire a TV, a console and a desktop, while NETGEAR’s Nighthawk app handles setup. Rated coverage is about 2,000 sq ft, a bit less than the G36, and there is no 2.5 Gbps port. One detail many reviews skip: NETGEAR’s own listing supports it on Xfinity plans only up to 800 Mbps, while Spectrum and Cox plans go up to 1 Gbps.
WHAT WE LIKE
✓ Four LAN ports
✓ Easy app setup
WATCH OUT FOR
✕ No 2.5 Gbps port
✕ Xfinity support only up to 800 Mbps plans
Skip it if: you are on Xfinity with a plan over 800 Mbps. The G36 is approved for plans up to about 1.2 Gbps.
Which Modem Should You Buy?
Pick by Plan Speed
- Up to 1 Gbps: ARRIS SB8200
- Over 1 Gbps: ARRIS S34, Motorola MB8611 or Hitron CODA56
- Over 1 Gbps with a Gigabit-only router: NETGEAR CM3000
- Plan with faster uploads: ARRIS S34
Pick by Setup
- Already own a good router: any modem-only pick
- Replacing a rented gateway: ARRIS G36
- Apartment: NETGEAR CAX30
- Large home: modem plus a mesh system
Buying vs Renting: What You Actually Save
Equipment fees depend on your provider and your plan, and some newer plans also include the gateway in the price. These are the typical numbers reported for 2026:
| Provider | What renting usually costs | Worth knowing |
|---|---|---|
| Xfinity | About $14 to $15 a month on plans that charge for the gateway | Many newer plans include the gateway, so check your bill first |
| Spectrum | The modem is included; the WiFi router costs about $5 to $7 a month on many plans | Your own router removes the router fee; your own modem mainly buys you control and speed |
| Cox | About $13 to $15 a month for the Panoramic WiFi gateway | Cox and Spectrum’s parent company Charter are merging, so Cox equipment fees may change |
The math is simple. At $15 a month, a modem that costs around $180 pays for itself in a year, and every month after that is money you keep. If your plan already includes the gateway, buy your own only when you want something the rented box cannot give you, such as a 2.5 Gbps port, better WiFi or full control of your network.
Should You Wait for a DOCSIS 4.0 Modem?
No. As of October 2026 you cannot buy a DOCSIS 4.0 modem in stores. Comcast’s DOCSIS 4.0 service runs on its own rented gateways, and the lists of modems customers can buy are still DOCSIS 3.1. Industry guides expect retail 4.0 modems in 2027 at the earliest, and the first ones will cost more than today’s models. Meanwhile, a DOCSIS 3.1 modem with a 2.5 Gbps port handles every plan most homes can get today.
DOCSIS 3.0 vs 3.1: Why Every Pick Is 3.1
DOCSIS is the standard your modem uses to talk to the cable company. 3.0 modems are still for sale, and they are cheap for a reason: providers are phasing them out, and they struggle on plans near or above 1 Gbps. A 3.1 modem, however, handles today’s plans and the faster ones being rolled out now. So if a modem looks suspiciously cheap, check this spec first.
Got Fiber? Skip the Modem
Cable modems only work on cable internet, the kind that comes in through a round coax cable. Fiber providers instead install their own box, called an ONT, and you plug a router straight into it. If that is your setup, read our guide to the best router for fiber internet instead.
Setting Up Your New Modem
- Confirm the model is on your provider’s approved list for your plan.
- Connect the coax cable from the wall, plug in the power and wait for the lights to show it is online. The first boot can take several minutes.
- Activate it with your provider through their app or activation page. Some ask you to call with the MAC address printed on the label.
- Connect your router to the modem’s fastest port. On a multi-gig plan, that is the 2.5 Gbps port into your router’s multi-gig WAN port.
- Return the rented equipment and keep the receipt so the fee comes off your bill.
Frequently Asked Questions
Is it worth buying your own modem?
Usually, yes. A good modem often pays for itself within a year or two of rental fees, and you choose the hardware instead of taking whatever the provider has in the warehouse.
What is the best modem for Xfinity, Spectrum or Cox?
The ARRIS SURFboard S34 is the safest all-round pick, since ARRIS says it is tested with all three. Still check your provider’s list, because support can depend on the plan.
Will a better modem make my internet faster?
Not beyond your plan. But an old DOCSIS 3.0 modem, or a Gigabit port on a multi-gig plan, can stop you getting the speed you already pay for.
Modem plus router, or a combo?
Separate boxes are more flexible, because you can upgrade the WiFi later. A combo, however, is simpler and takes less space. Both work; it mostly depends on whether you already own a router.
Do these modems support a home phone line?
No. None of them have phone ports, so keep your provider’s voice modem if you have phone service through them.
Pair Your Modem With the Right Router
- Best Budget WiFi Router – seven affordable routers worth buying
- On Xfinity? See the best router for Xfinity for picks that work well on Comcast plans
- Best Router for Spectrum – compatible routers for Spectrum internet
- When one router is not enough, read our guide to the best WiFi router for large homes
Final Recommendation
For most cable homes, the ARRIS SURFboard S34 is the modem to buy: DOCSIS 3.1, a 2.5 Gbps port and support for faster upload plans on Xfinity, Spectrum and Cox. Gamers, however, should look at the Motorola MB8611. If your plan is 1 Gbps or slower, save money with the ARRIS SB8200. Prefer one box? The ARRIS G36. And whichever you choose, check your provider’s approved list first.