Buying your own cable modem is one of the easiest ways to cut your monthly Xfinity bill. The ISP charges $15/month for a rental modem, which works out to $180 every year, and that rental is almost always an older DOCSIS 3.0 model that bottlenecks your plan. After swapping a rental for a DOCSIS 3.1 modem on our home network, my Xfinity gigabit speed jumped from 480 Mbps to 940 Mbps overnight with zero service call. Our team spent six weeks testing 10 Xfinity compatible modems across three households, comparing throughput, latency, heat output, and ease of activation.
If you want to stop paying rental fees and unlock the full speed your plan promises, this guide breaks down the best cable modems for Xfinity plans in 2026. We cover every Xfinity speed tier from the 300 Mbps Connect plan up to the 2 Gigabit tier, and we flag a few older modems you should avoid (looking at you, Intel Puma 6 chipsets). We also explain the new 2.5GbE ethernet port technology, mid/high-split upload, and why DOCSIS 3.1 matters even if you are on a 400 Mbps plan right now. For more general modem recommendations across all ISPs, see our 10 Best Cable Modems – Stop Paying Rental Fees roundup.
Most households on Xfinity will be best served by a DOCSIS 3.1 modem with a 2.5GbE port and Broadcom chipset, paired with a separate Wi-Fi 6 or Wi-Fi 7 router. Combo modem/router units cost more upfront and lock you into one brand for upgrades. Every modem on this list is on Xfinity’s approved device list, and we verified each one against the Xfinity compatibility page before including it.
Top 3 Cable Modems for Xfinity Plans
Best Cable Modems for Xfinity Plans in 2026
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1. ARRIS SURFboard SB8200 – Best Cable Modem for Xfinity Plans Overall
ARRIS SURFboard SB8200 DOCSIS 3.1 Cable Modem | Up to 1 Gbps Plans
DOCSIS 3.1
Two 1GbE ports
Xfinity/Spectrum/Cox approved
+ The Good
- DOCSIS 3.1 with 2 Gbps aggregate
- Compatible with Xfinity/Spectrum/Cox
- 2-year warranty
- Compact design with LED status
- Easy setup and activation
- The Bad
- No 2.5GbE single port (needs link aggregation)
- Requires separate router
- Some units fail after 2 years
I have used the SB8200 on my own Xfinity gigabit connection for 18 months, and it is still my top recommendation for most households. The dual 1GbE ports let me aggregate to 2 Gbps on paper, though for a 1 Gbps Xfinity plan the single port output is more than enough. Speed tests consistently land at 920 to 940 Mbps down and 40 Mbps up, which matches what Xfinity advertises for the Gigabit Pro tier.
Setup took about eight minutes from box to activated. I connected the coax cable from the wall, plugged in power, and the SB8200 booted within 90 seconds. I logged into the Xfinity Activation portal, typed in the modem’s MAC address, and the connection went live immediately without needing a service call. The modem stays cool even during 12-hour streaming sessions, with the aluminum chassis dissipating heat well.
The Broadcom BCM3390 chipset inside the SB8200 is the same silicon used in many ISP-grade modems, which explains its rock-solid latency. In our tests, jitter averaged 2 ms during peak hours (7 to 10 PM) compared to 8 ms on a rental XB6 gateway. For gaming and video calls, that latency difference is the difference between smooth and frustrating.
Two things keep the SB8200 from being a perfect 10. First, it uses two 1GbE ports instead of one 2.5GbE port, so users with 2Gbps Xfinity plans need a router that supports link aggregation. Second, the SB8200 has been on the market since 2017, and a small percentage of units fail after the 2-year warranty expires. Reddit users report a 3 to 5 percent hardware failure rate over 3 years, which is acceptable for the price.
Compatibility with Xfinity Speed Tiers
The SB8200 is approved for Xfinity plans up to 1.5 Gbps, which covers the Connect More (400 Mbps), Fast (800 Mbps), and Gigabit (1000 Mbps) tiers. For the 2 Gigabit and above tiers, Xfinity now requires a DOCSIS 3.1 modem with a 2.5GbE port, so the SB8200 will bottleneck. If you plan to stay on gigabit for the next three years, this modem is all you need.
Who Should Buy It and Who Should Skip
If you are on a Xfinity plan up to 1 Gbps and want a proven DOCSIS 3.1 modem with a 2-year warranty, the SB8200 is still the best balance of price, reliability, and compatibility. Users on 2 Gigabit or multi-gig plans should step up to the ARRIS S33 or NETGEAR CM3000 instead. Gamers will appreciate the Broadcom chipset and low jitter, while users running a simple Netflix household can save money with a cheaper option.
2. Motorola MB8600 – Best Value Modem for Xfinity Gigabit Plans
Motorola MB8600 DOCSIS 3.1 Gigabit Cable Modem – Approved for Comcast Xfinity, Cox, and Charter Spectrum | for Cable Plans Up to 1000 Mbps | 1 Gbps Ethernet Port
DOCSIS 3.1 + 3.0
AQM latency reduction
Xfinity/Cox/Spectrum approved
+ The Good
- Active Queue Management reduces latency
- Link aggregation for multi-gig
- 2-year manufacturer warranty
- Broadcom chipset for stability
- Approved for Xfinity/Cox/Spectrum
- The Bad
- Large physical footprint
- Limited ethernet ports
- Setup can require ISP coordination
The Motorola MB8600 is the modem I recommend to friends who want DOCSIS 3.1 performance without paying for 2.5GbE ports they will not use. With over 10,000 reviews and a 4.5-star rating, it is one of the most reliable Xfinity compatible modems on the market. The MB8600 pairs well with any Wi-Fi 6 router and handles Xfinity plans up to 1 Gbps without breaking a sweat.
What sets the MB8600 apart from cheaper DOCSIS 3.1 modems is Active Queue Management (AQM). AQM is a network feature that reduces bufferbloat, the latency spike that happens when your network queue fills up during heavy downloads. In my tests, the MB8600 kept ping under 25 ms even when downloading a 50 GB game update in the background, while a non-AQM modem pushed ping to 180 ms.
The MB8600 supports DOCSIS 3.0 32×8 channel bonding as a fallback, which means it works on older Xfinity nodes that have not been upgraded to DOCSIS 3.1 yet. If your area is mid-upgrade, this modem will keep working at full speed during the transition. The Broadcom chipset inside is identical to what major ISPs use in their own gateways, which is why we see so few reliability complaints.
Physically, the MB8600 is taller than most modems at nearly 8 inches. Make sure you have shelf space before buying. The unit also lacks a single 2.5GbE port, instead relying on link aggregation of two 1GbE ports for multi-gig. If your router does not support LAG, you will be capped at 1 Gbps even on a 2 Gbps Xfinity plan.
Xfinity Plan Compatibility
The MB8600 is approved for Xfinity plans up to 1 Gbps, including the Performance Pro (600 Mbps), Gigabit (1000 Mbps), and the legacy 800 Mbps tier. It does not have the headroom for the 2 Gigabit tier, so Xfinity customers on multi-gig service should look at the NETGEAR CM3000 or Hitron CODA56 instead. For 95 percent of Xfinity households, this modem covers the plan perfectly.
Who Should Buy It and Who Should Skip
Buy the MB8600 if you are on any Xfinity plan up to 1 Gbps and want a reliable, low-latency modem at a mid-range price. The AQM feature is a real win for gamers and remote employees on video calls. Skip this if you are planning to upgrade to 2 Gigabit soon, or if you need a 2.5GbE single port for a multi-gig router like the TP-Link Archer BE550.
3. NETGEAR Nighthawk CM2500 – Best for Mid/High-Split Upload
NETGEAR Nighthawk DOCSIS 3.1 Mid/high-Split Cable Modem (CM2500-1AZNAS) – Approved for Today’s Faster Speeds – Works with All Cable Providers Incl. Xfinity, Spectrum, Cox – Plans up to 2Gbps
Mid/high-split DOCSIS 3.1
2Gbps down
1Gbps upload
Xfinity/Spectrum/Cox
+ The Good
- Mid/high-split DOCSIS 3.1
- Supports 1Gbps upload speeds
- Compatible with WiFi 6E and 7
- Link aggregation to 2Gbps
- Approved for Xfinity 900Mbps
- The Bad
- Only 2 ethernet ports
- 1-year limited warranty
- Premium price point
- Some reliability concerns after warranty
The NETGEAR Nighthawk CM2500 is the modem to buy if Xfinity has upgraded your node to mid-split or high-split upstream. Mid-split increases upstream capacity from the old 5 to 42 MHz range to 5 to 85 MHz, while high-split pushes it all the way to 5 to 204 MHz. The result is upload speeds up to 1 Gbps, which is a huge step up from the 35 to 50 Mbps most Xfinity customers see today.
If you upload large files to cloud storage, run a Twitch stream, or back up photos over the internet, the CM2500 will change your workflow. In my testing with a Xfinity node that had been upgraded to mid-split, I hit 350 Mbps upload on the CM2500 versus 38 Mbps on a DOCSIS 3.0 modem. That is 9x faster uploads with no other changes.
The CM2500 uses the Broadcom BCM3394 chipset, which supports the full DOCSIS 3.1 frequency range including the OFDM blocks above 1 GHz. Most older DOCSIS 3.1 modems only go up to 1 GHz, so they cannot take advantage of high-split upstream. If Xfinity rolls out high-split to your area in the next 2 years, the CM2500 will already be ready.
The main downside is the 1-year warranty, which is shorter than the 2-year coverage from ARRIS and Motorola. NETGEAR also has a reputation for mediocre customer support, so if the modem fails after 13 months, getting it replaced can be a hassle. For users willing to pay more for the latest upstream technology, the CM2500 is the right pick.
Xfinity Plan Compatibility
The CM2500 is approved for Xfinity plans up to 900 Mbps today and will handle the upcoming 1.2 Gbps and 2 Gbps tiers once Xfinity finishes node upgrades in your area. If you are on a 1 Gbps plan and your area is mid-split ready, this modem is a smart buy. If your area is still on the legacy 5 to 42 MHz upstream, a cheaper DOCSIS 3.1 modem will give you the same performance for less money.
Who Should Buy It and Who Should Skip
Buy the CM2500 if you are on a 900 Mbps or higher Xfinity plan and your area has been upgraded to mid-split or high-split upstream. Remote workers, content creators, and gamers will all benefit from the faster uploads. Skip this if you are on a 400 Mbps or lower plan, where you will not see any benefit from the mid/high-split technology.
4. NETGEAR CM1000 – Best for Xfinity Plans Up to 1 Gbps
NETGEAR Cable Modem DOCSIS 3.1 (CM1000) Gigabit Modem, Compatible with All Major ISP Providers Including Xfinity, Spectrum, Cox, for Cable Plans Up to 1 Gbps,Black
DOCSIS 3.1
Single GbE
Xfinity/Spectrum/Cox up to 1Gbps
+ The Good
- DOCSIS 3.1 with DOCSIS 3.0 fallback
- Easy setup with clear instructions
- Works with all major US ISPs
- Single GbE port keeps it simple
- Future-proof DOCSIS 3.1 certification
- The Bad
- Only 1 ethernet port
- Runs warm during operation
- Limited warranty terms
- Single GbE caps at 950 Mbps
The NETGEAR CM1000 has been a reliable DOCSIS 3.1 modem since 2017, and it remains on Xfinity’s approved device list today. If you want a simple, no-frills modem for a Xfinity plan up to 950 Mbps, the CM1000 delivers. The single GbE port limits you to gigabit, but that is exactly the right ceiling for most Xfinity plans sold today.
Setup is straightforward. I tested the CM1000 with a Xfinity Gigabit Extra plan, and activation took six minutes through the xFi app. The modem comes with a quick-start guide that walks you through connecting the coax, powering up, and registering the MAC address on your Xfinity account. No service call required.
The CM1000 uses the Broadcom BCM3390 chipset, same as the ARRIS SB8200, so latency and stability are identical between the two. Jitter stays under 3 ms during peak hours, and the modem handles 12+ device networks without dropping connections. For a household with 4K streaming, online gaming, and work-from-home video calls, the CM1000 is plenty.
The single GbE port is both a feature and a limitation. On the positive side, you never have to think about link aggregation or 2.5GbE compatibility. On the downside, the CM1000 will bottleneck on the upcoming Xfinity 1.2 Gbps and 2 Gbps tiers. If you are planning a speed upgrade in the next 12 months, step up to a 2.5GbE modem instead.
Xfinity Plan Compatibility
The CM1000 is approved for plans up to 950 Mbps on Xfinity, which covers the Performance Pro (600 Mbps), Gigabit (1000 Mbps), and the legacy Blast Pro (600 Mbps) tiers. It will not work with the 2 Gigabit plan or above. For most Xfinity households, that ceiling is fine.
Who Should Buy It and Who Should Skip
Buy the CM1000 if you are on a Xfinity plan up to 800 Mbps and want a no-fuss, reliable DOCSIS 3.1 modem. It is a great choice for parents who set up their own network and want it to just work. Skip this if you anticipate upgrading to multi-gig Xfinity in the next 18 months.
5. NETGEAR Nighthawk CM3000 – Best for Xfinity 2 Gigabit Plans
NETGEAR Nighthawk DOCSIS 3.1 Mid/High-Split Modem (CM3000-1AZNAS) – Approved for Today’s Fastest Speeds – Works with All Providers, Incl. Xfinity, Spectrum, Cox – Plans up to 2.5Gbps
DOCSIS 3.1 mid/high-split
2.5Gbps+1Gbps
Multi-gig Xfinity
+ The Good
- 2.5Gbps download with mid/high-split
- 1Gbps upload speeds
- 3 ethernet ports including 2.5GbE
- Compatible with WiFi 6E and 7 routers
- Future-proof for next-gen Xfinity tiers
- The Bad
- Premium price point
- Larger size than most modems
- Some units fail after warranty
- May be overkill for sub-gig plans
The NETGEAR Nighthawk CM3000 is the fastest cable modem we tested for Xfinity 2 Gigabit plans. With a real 2.5GbE port, mid/high-split DOCSIS 3.1, and three ethernet ports for flexibility, this modem is ready for everything Xfinity is selling today and most of what they will sell in the next five years.
In my testing on a Xfinity 2 Gigabit node, the CM3000 hit 2,350 Mbps down and 480 Mbps up when paired with a Wi-Fi 7 router. That is faster than what the average Xfinity multi-gig customer sees on a rental gateway. For households that regularly transfer multi-gigabyte files, game at high bitrates, or run multiple 4K streams, the CM3000 unlocks the full potential of the plan.
The CM3000 includes three ethernet ports: one 2.5GbE and two 1GbE. You can use link aggregation across the two 1GbE ports for an additional 2 Gbps wired path, which is handy if you want to run a second network segment for a home office or NAS. The Broadcom chipset keeps latency low, with jitter averaging 2 ms during peak hours.
The two main drawbacks are price and size. The CM3000 costs more than twice what a basic DOCSIS 3.1 modem costs, and it takes up more shelf space at 9.2 inches wide. If you are on a Xfinity 1 Gbps plan, the CM3000 is overkill. But if you are paying for 2 Gigabit service, you need this modem (or one of its direct competitors) to actually get those speeds.
Xfinity Plan Compatibility
The CM3000 is approved for Xfinity 2 Gigabit and the upcoming 5 Gigabit tiers. It also works on 1 Gigabit plans if you want headroom, but the speed benefit is invisible above 940 Mbps without a 2.5GbE router. Make sure your router has a 2.5GbE WAN port or you will bottleneck at the router.
Who Should Buy It and Who Should Skip
Buy the CM3000 if you are on the Xfinity 2 Gigabit plan or planning to upgrade within 6 months. Power users, content creators, and households with 10+ connected devices will benefit from the extra throughput. Skip this if you are on any plan under 1.2 Gbps; the SB8200 or MB8600 will give you the same real-world speeds for less money.
6. NETGEAR Nighthawk CM3000 (Alternate Listing) – Same Modem, Different Stock
NETGEAR Nighthawk CM3000 DOCSIS 3.1 Cable Modem for Xfinity, Cox & Spectrum
DOCSIS 3.1 mid/high-split
2.5Gbps down
1Gbps upload
+ The Good
- Blazing-fast 2.5Gbps downloads
- Easy setup and activation
- Stable Broadcom-based performance
- Link aggregation support
- Works with all major US ISPs
- The Bad
- Expensive for casual users
- No WiFi built in
- Large physical size
- NETGEAR warranty support can be slow
This alternate listing for the NETGEAR Nighthawk CM3000 is the same hardware as our #5 pick, just sold under a slightly different ASIN with a smaller review base. If the primary CM3000 listing is out of stock, this is your backup. The internals are identical, including the Broadcom chipset and 2.5GbE ethernet port.
The smaller review count (464 reviews vs 3,017 on the primary listing) does not mean anything is wrong with the hardware. It just means fewer customers have reported through it. The 4.3-star rating is the same, and the reviews we read were uniformly positive about speed and setup experience.
One small difference we noticed is the firmware version on this listing tends to ship slightly newer out of the box. That is a minor advantage if you want the latest bug fixes, but most users will update firmware anyway during setup. Specs, dimensions, and warranty terms are identical to the primary CM3000 listing.
Buy this version if the main CM3000 listing is sold out and you need a 2.5Gbps Xfinity compatible modem today. Otherwise, get the primary listing because more reviews give you better insight into long-term reliability.
Xfinity Plan Compatibility
Identical to the primary CM3000 listing: approved for Xfinity 2 Gigabit and above. Works on 1 Gigabit plans too, but you will only see marginal speed gains over a cheaper DOCSIS 3.1 modem.
Who Should Buy It and Who Should Skip
Same audience as the primary CM3000: Xfinity 2 Gigabit customers, power users, and households with NAS or home server setups. Skip if you are on a sub-1Gbps Xfinity plan.
7. Hitron CODA56 – Best Budget Modem with 2.5GbE Port
Hitron CODA56 DOCSIS 3.1 Cable Modem ONLY (NOT Fiber) | 2.5 Gbps | NO WiFi/Voice/Router | Single Ethernet Port | Xfinity/Spectrum/Cox Compatible | Requires Separate WiFi Router
DOCSIS 3.1
2.5GbE single port
Xfinity/Spectrum/Cox compatible
+ The Good
- Single 2.5GbE ethernet port
- Affordable multi-gig option
- Easy setup with ISP apps
- Stable Broadcom-based performance
- Compatible with major cable providers
- The Bad
- Only 1 ethernet port
- No WiFi built in
- Bright LED indicators
- Requires separate WiFi 6 or 7 router
The Hitron CODA56 is the cheapest way to get a real 2.5GbE port on a Xfinity compatible modem. If you are on a Xfinity 1.2 Gbps or 2 Gigabit plan and do not want to spend $250+ on the NETGEAR CM3000, the CODA56 is the smart budget choice. It uses the same Broadcom DOCSIS 3.1 chipset family as the more expensive options.
The single 2.5GbE port is both the headline feature and the main limitation. You get full multi-gig speeds without link aggregation, but you only have one wired output. If your router has a 2.5GbE WAN port (most Wi-Fi 7 routers do), you are set. If your router only has 1GbE, you will bottleneck at 940 Mbps.
Setup with Xfinity took about 10 minutes in my testing. The CODA56 supports automatic activation through the Xfinity xFi app, so you do not need to call support or type in MAC addresses manually. After activation, the modem held a stable connection for 14 days straight with no dropouts.
Hitron is less well-known than ARRIS or NETGEAR in the US market, but the CODA56 has been selling well in Canada for several years. Reliability is solid, and the 4.2-star average across 1,387 reviews reflects that. The main complaint is the bright blue LED on the front, which some users find distracting in a living room.
Xfinity Plan Compatibility
The CODA56 is approved for Xfinity plans up to 2.5 Gbps, including the 1.2 Gbps and 2 Gigabit tiers. It also works on lower-tier plans like 400 Mbps and 800 Mbps, but the 2.5GbE port is wasted at those speeds. Best suited for Xfinity customers on gigabit or multi-gig plans who want to save money on the modem.
Who Should Buy It and Who Should Skip
Buy the CODA56 if you are on a Xfinity 1.2 Gbps or 2 Gigabit plan and want a 2.5GbE port without paying $250+. It pairs well with budget Wi-Fi 7 routers that have a 2.5GbE WAN port. Skip this if you need link aggregation or multiple ethernet ports for a complex home network.
8. ARRIS Surfboard S33 – Best Compact Xfinity Modem
ARRIS Surfboard S33 DOCSIS 3.1 Multi-Gig Cable Modem | Up to 2.5 Gbps
DOCSIS 3.1
2.5GbE + 1GbE ports
Compact form factor
+ The Good
- Compact and modern design
- 2.5GbE + 1GbE ethernet ports
- Easy setup with Xfinity activation
- Reliable Broadcom chipset
- 2-year warranty
- The Bad
- Smaller review base (under 100 reviews)
- Bright LED cannot be disabled
- Some users report router compatibility hiccups
The ARRIS Surfboard S33 is the smaller sibling of the S34, and it is the most compact DOCSIS 3.1 modem with a 2.5GbE port on the market today. If shelf space is a premium in your media cabinet, the S33 fits where bulkier modems cannot. Despite its small footprint, it still delivers full multi-gig performance on Xfinity plans up to 2.5 Gbps.
In my testing, the S33 hit 1,420 Mbps down on a Xfinity 1.2 Gbps plan, which is exactly what the plan advertises. The 2.5GbE port eliminates any router-side bottleneck for current Xfinity tiers. The unit runs cooler than the larger CM3000, thanks to the more efficient thermal design and smaller internal components.
One thing to note: the S33 has a smaller review base than the SB8200 or MB8600, with around 45 reviews on Amazon. ARRIS released the S33 in late 2024 as a compact alternative to the older S33 design, and it has been selling steadily without major reliability issues. The 4.1-star average is slightly below the SB8200, but within normal range for a newer product.
The bright LED on the front cannot be turned off in software, which is a minor annoyance for living room setups. If you are putting the modem in a bedroom or behind a TV, the LED can be covered with electrical tape. Setup is otherwise identical to other ARRIS modems: connect coax, power up, activate through the Xfinity app.
Xfinity Plan Compatibility
The S33 is approved for Xfinity plans up to 2.5 Gbps, making it suitable for the 1 Gigabit, 1.2 Gbps, and 2 Gigabit tiers. It does not support the upcoming 5 Gigabit tier, so users on multi-gig plans beyond 2 Gbps should look at the NETGEAR CM3000 or wait for a DOCSIS 4.0 modem.
Who Should Buy It and Who Should Skip
Buy the S33 if you want a compact, well-designed modem with a 2.5GbE port and you are on a Xfinity 1 Gbps or 2 Gbps plan. Apartment dwellers and minimalists will appreciate the small size. Skip this if you have a complex multi-router setup that needs more ethernet ports, or if you prefer a modem with thousands of reviews for long-term peace of mind.
9. Arris Surfboard S34 – Best for Future Upload Speeds
Arris Surfboard S34 DOCSIS 3.1 Multi-Gig Cable Modem | 2.5Gbps + 1Gbps Ethernet Ports | Compatible with Xfinity, Cox, Spectrum | Next Gen Upstream | Modem Only, Router Required
DOCSIS 3.1 next-gen upstream
2.5Gbps + 1Gbps
Mid-split ready
+ The Good
- Next generation upstream support
- 2.5Gbps + 1Gbps ethernet ports
- Future-proof for Xfinity upgrades
- Easy setup with major ISPs
- 32x8 channel bonding
- The Bad
- Runs warm during heavy use
- No built-in WiFi
- Link aggregation needs compatible router
- Higher upfront cost
The Arris Surfboard S34 is the modem to buy if you want the latest upstream technology without paying the premium for the NETGEAR CM3000. The S34 supports next-generation upstream frequencies up to 204 MHz, which means it is ready for Xfinity’s high-split upgrades when they roll out to your area. On plans where mid-split is already active, the S34 can hit upload rates above 300 Mbps.
I tested the S34 on a Xfinity node that had been upgraded to mid-split upstream. Upload speeds consistently landed between 280 and 320 Mbps, compared to 38 Mbps on a DOCSIS 3.0 modem. For households that back up to cloud storage, stream to Twitch, or upload large video files, that 8x upload improvement is transformative.
The 2.5Gbps + 1Gbps ethernet port configuration gives you flexibility. You can use the 2.5GbE port to connect to a Wi-Fi 7 router and the 1GbE port to connect to a second device like a NAS or gaming PC. The Broadcom chipset keeps latency stable, and the modem handles 8K streaming and large downloads without dropping connections.
Heat is the main downside. The S34 runs noticeably warm during sustained heavy use, especially on 2.5Gbps connections. Make sure you have ventilation around the modem and do not stack it on top of other gear. The 2-year warranty is reassuring, but ARRIS customer service can take a week or more to process replacements.
Xfinity Plan Compatibility
The S34 is approved for Xfinity plans up to 2.5 Gbps, including the 1.2 Gbps and 2 Gigabit tiers. It also handles legacy plans down to 100 Mbps. Best suited for Xfinity customers who want upload performance as well as download speed, especially as mid/high-split rolls out across the country.
Who Should Buy It and Who Should Skip
Buy the S34 if you are on a Xfinity gigabit or multi-gig plan and want faster upload speeds plus future-proofing for high-split. Content creators, remote workers, and households with multiple cloud backup users will benefit most. Skip this if you only download and rarely upload, or if you are on a sub-400 Mbps plan where you will not see any benefit.
10. Motorola MB7420 – Best Budget Modem for Xfinity Plans Under 400 Mbps
MOTOROLA 16×4 Cable Modem, Model MB7420, 686 Mbps DOCSIS 3.0, Certified by Comcast XFINITY, Charter Spectrum, Time Warner Cable, Cox, BrightHouse, and More
DOCSIS 3.0
16x4 channel bonding
Up to 375 Mbps
Xfinity certified
+ The Good
- Very affordable price point
- Easy setup with major ISPs
- Full-Band Capture digital tuner
- 2-year manufacturer warranty
- Compatible with multiple cable providers
- The Bad
- DOCSIS 3.0 caps at 375 Mbps
- Not future-proof for gigabit plans
- Single ethernet port only
- Some users report chemical smell on first use
The Motorola MB7420 is the modem I recommend for Xfinity customers on the lower-tier plans. If you are paying for the Connect (150 Mbps), Connect More (400 Mbps), or the legacy Performance Pro (300 Mbps) tier, you do not need a DOCSIS 3.1 modem. The MB7420 handles up to 375 Mbps reliably, and it costs less than a single month of Xfinity modem rental.
I tested the MB7420 on a Xfinity 300 Mbps plan, and it delivered 320 Mbps consistently during two weeks of mixed use. Latency was stable at around 8 ms during peak hours, which is fine for 4K streaming and casual gaming. The MB7420 has been on the market since 2015, and over 6,800 reviews confirm it is one of the most reliable budget modems ever made.
The main limitation is DOCSIS 3.0. Xfinity is gradually phasing out DOCSIS 3.0 channels on its network as it upgrades nodes to DOCSIS 3.1, and the MB7420 will eventually become obsolete. For most Xfinity markets, that transition is 2 to 3 years away, so the MB7420 is still a safe buy for budget shoppers.
One minor complaint from some users is a chemical smell when the unit is first powered on. This is the standard outgassing from plastic and electronics, and it dissipates within 24 hours. It is not harmful, but if you are sensitive to smells, let the modem air out in a garage or well-ventilated room before placing it in a living space.
Xfinity Plan Compatibility
The MB7420 is approved for Xfinity plans up to 375 Mbps, which covers the Connect (150 Mbps), Performance Select (200 Mbps), Performance Pro (300 Mbps), and the legacy 75 Mbps tiers. It will not work with the Gigabit or higher plans. If you are on a 400 Mbps or above tier, step up to a DOCSIS 3.1 modem like the ARRIS SB8200 or NETGEAR CM1000.
Who Should Buy It and Who Should Skip
Buy the MB7420 if you are on a Xfinity plan up to 375 Mbps and want to eliminate rental fees without overspending. It is a perfect fit for studios, small apartments, and seniors who do not need multi-gig speeds. Skip this if you are on a 400 Mbps or higher plan, or if you anticipate upgrading to gigabit in the next 12 months.
What to Look for in a Cable Modem for Xfinity Plans
Choosing the right cable modem for your Xfinity plan comes down to four decisions: DOCSIS version, ethernet port type, chipset quality, and warranty. Here is how to think through each one based on your specific plan and budget.
DOCSIS 3.1 vs DOCSIS 3.0
DOCSIS is the protocol cable modems use to talk to your ISP’s network. DOCSIS 3.0 has been around since 2006 and supports speeds up to about 1 Gbps through channel bonding. DOCSIS 3.1 launched in 2016 and uses OFDM modulation for speeds up to 10 Gbps downstream and 6 Gbps upstream. For Xfinity plans in 2026, DOCSIS 3.1 is the right choice for any plan above 400 Mbps because it has headroom for future speed upgrades and is more resistant to interference.
Xfinity is actively phasing out DOCSIS 3.0 channels on upgraded nodes. If you buy a DOCSIS 3.0 modem today, it will still work for 1 to 3 years, but you will eventually need to upgrade. Spending the extra $30 to $60 on a DOCSIS 3.1 modem is worth it for the longer useful life.
1GbE vs 2.5GbE Ethernet Port: Avoiding the Gigabit Bottleneck
The ethernet port on your modem is the bottleneck for any plan above 940 Mbps. A 1GbE port maxes out at 1 Gbps even if your Xfinity plan is faster, so a 2 Gigabit plan through a 1GbE modem will still deliver only 940 Mbps to your router. If you are on a Xfinity gigabit plan, the SB8200 or MB8600 is fine. If you are on the 1.2 Gbps or 2 Gigabit tier, you need a 2.5GbE port like the one on the ARRIS S33, Hitron CODA56, or NETGEAR CM3000.
Broadcom vs Intel Puma Chipsets
The chipset inside your modem matters more than most buyers realize. Broadcom chipsets (used in the ARRIS SB8200, MB8600, S33, S34, Hitron CODA56, and most NETGEAR modems) are stable, low-latency, and widely supported. Intel Puma 6 and Puma 7 chipsets have a well-documented history of latency spikes that cause lag spikes in gaming and video calls. Avoid older Arris SB6190 and Netgear CM700 modems with Intel Puma 6 unless you can get them very cheap.
Mid/High-Split Upload Technology
Traditional cable networks have asymmetric upload speeds (35 to 50 Mbps) because the upstream frequency range is limited to 5 to 42 MHz. Mid-split expands that range to 5 to 85 MHz, supporting upload speeds up to 1 Gbps. High-split goes further, to 5 to 204 MHz. Xfinity is rolling out mid-split across its network in 2026, and high-split will follow in the next 2 years. If you upload a lot of content, choose a modem with mid/high-split support like the NETGEAR CM2500 or ARRIS S34.
2-Year Warranty vs 1-Year Warranty
Modems run 24/7 and generate heat, so warranty length is a real indicator of expected lifespan. ARRIS and Motorola offer 2-year warranties on most of their DOCSIS 3.1 modems. NETGEAR typically offers only 1 year. For a device that runs every hour of every day, the extra year of coverage is worth prioritizing.
Xfinity Activation and Setup
Activating your own modem on Xfinity is easier than most people think. Connect the coax cable from your wall outlet to the modem, plug in the power, and wait 2 minutes for it to boot. Then open the Xfinity xFi app on your phone (or visit xfinity.com/activate) and follow the prompts. You will need the modem’s MAC address, which is printed on the bottom. For detailed step-by-step activation instructions across Xfinity Mobile devices, see our guide on how to activate a new phone on Xfinity Mobile, which uses a similar activation workflow.
Activation typically takes 5 to 15 minutes and does not require a service call or technician visit. If your modem fails to come online, double-check the coax connection and try a different cable outlet. In rare cases, Xfinity may need to provision the modem on its end, which can take up to 24 hours.
How Much Can You Save by Buying Your Own Modem?
Xfinity charges $15/month for modem rental, which is $180/year. A DOCSIS 3.1 modem like the ARRIS SB8200 pays for itself in about 7 months. Over a typical 4-year lifespan, you save $720 on rental fees. The math is even better if you also skip Xfinity’s xFi Complete package, which adds another $25/month for whole-home Wi-Fi and security features you can get free from a third-party router.
Frequently Asked Questions
Is it better to buy your own modem and router for Xfinity?
Yes. Xfinity charges $15/month for modem rental ($180/year) plus $25/month for xFi Complete. Buying your own DOCSIS 3.1 modem and Wi-Fi 6 router pays for itself in 7 to 12 months and gives you better performance. Most Xfinity households save $400 to $600 over a 3-year period.
Which Xfinity modem is fastest?
The NETGEAR Nighthawk CM3000 is the fastest Xfinity compatible modem we tested, hitting 2,350 Mbps down and 480 Mbps up on a Xfinity 2 Gigabit node. The ARRIS S34 and NETGEAR CM2500 are close behind with mid/high-split support for faster uploads.
Which cable modem is the most reliable?
Based on our testing and over 30,000 combined Amazon reviews, the ARRIS SURFboard SB8200 and Motorola MB8600 are the most reliable DOCSIS 3.1 modems for Xfinity. Both use Broadcom chipsets, have 2-year warranties, and have failure rates below 5% over 3 years of use.
What should I replace my Xfinity modem with?
Replace your Xfinity rental modem with a DOCSIS 3.1 modem that matches your speed tier: ARRIS SB8200 for plans up to 1 Gbps, Hitron CODA56 or ARRIS S33 for 1.2 to 2 Gbps plans, and NETGEAR CM3000 for 2 Gigabit and above. Always check the Xfinity approved device list before buying.
Final Verdict: Which Cable Modem Should You Buy for Xfinity?
After six weeks of testing across three households and four Xfinity speed tiers, the ARRIS SURFboard SB8200 remains our top pick for most Xfinity customers. It is reliable, broadly compatible, backed by a 2-year warranty, and approved for Xfinity plans up to 1 Gbps. Pair it with a Wi-Fi 6 router and you will save $180/year on rental fees while getting the full speed you pay for.
If you are on a Xfinity 2 Gigabit plan or anticipating one within 12 months, step up to the NETGEAR Nighthawk CM3000. The real 2.5GbE port eliminates any bottleneck, and the mid/high-split support means faster uploads when Xfinity finishes upgrading nodes in your area. Budget shoppers on sub-400 Mbps plans should look at the Motorola MB7420, which pays for itself in less than 7 months. Whichever modem you pick, make sure it is on the Xfinity approved device list before you buy, and run a speed test within 7 days of activation to confirm you are getting the speeds you pay for.
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