# Best Modem for Xfinity in 2026: Picks by Plan

> The best modem for Xfinity depends on your plan: a DOCSIS 3.1 model for Gigabit, a 2.5G port for faster tiers, a voice modem for Xfinity Voice.

- URL: https://wifiweekly.com/guides/best-modem-for-xfinity/
- Type: Guide
- Topic: Internet Plans & ISPs
- Author: Tehseen Arbab
- Published: 2026-10-27
- Last updated: 2026-10-27
- Publisher: WiFi Weekly (https://wifiweekly.com/)

## Short answer

The best modem for Xfinity is one Xfinity's My Device Info tool lists for your address and plan. For plans up to 1 Gbps, a DOCSIS 3.1 modem such as the ARRIS SURFboard SB8200 fits; for faster tiers, look at 2.5 Gbps models like the SURFboard S34 (which ARRIS lists with next-gen upload support) or Motorola MB8611, and if you have Xfinity Voice, you need a voice modem such as the NETGEAR CM2050V. Before buying, note that Xfinity says customer-owned modems can't currently get X-Class speeds and that its latest plans include its gateway at no extra cost.

## Key takeaways

- Check Xfinity's My Device Info tool before you buy. Xfinity says your modem "must work with Xfinity and support your internet speed," and its support page doesn't name models.
- Xfinity says "customer-owned modems are not currently compatible with X-Class speeds," so X-Class plans need Xfinity's equipment.
- In recently upgraded areas, Xfinity says there are "limited retail modems, eMTAs or gateways" that support the faster upload speeds; older owned modems should keep working at the tiers available before the upgrade.
- For plans up to 1 Gbps, ARRIS rates the SURFboard SB8200 "best for cable internet speed plans up to 1 Gbps". For faster plans, the SURFboard S34 and Motorola MB8611 each have a 2.5 Gbps Ethernet port.
- If you have Xfinity Voice, you need a voice modem with phone ports. NETGEAR's CM2050V has two and says it requires an Xfinity Voice plan.

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The best modem for Xfinity is the one Xfinity's **My Device Info** tool lists for your address and plan. Within that list, pick by plan: a DOCSIS 3.1 modem with gigabit ports, such as the ARRIS SURFboard SB8200, for plans up to 1 Gbps; a model with a 2.5 Gbps Ethernet port, such as the SURFboard S34 or Motorola MB8611, for faster plans; and a voice modem, such as the NETGEAR CM2050V, if you have Xfinity Voice. Two things come before any of that: Xfinity says customer-owned modems can't currently get X-Class speeds, and its latest plans include its own gateway at no extra cost.

We haven't tested these modems. The picks below are based on manufacturer specifications and Xfinity's own support pages, checked on October 27, 2026. We left prices out because we couldn't confirm current retail prices.

## Quick picks by plan

| Your situation | Pick | Why |
|---|---|---|
| Plan up to 1 Gbps, no Xfinity Voice | ARRIS SURFboard SB8200 | DOCSIS 3.1; ARRIS rates it for plans up to 1 Gbps; two gigabit Ethernet ports |
| Plan above 1 Gbps, or you want room to upgrade | ARRIS SURFboard S34 | 2.5 Gbps Ethernet port; ARRIS lists "Next Gen Upstream" support |
| Alternative for faster plans | Motorola MB8611 | 2.5 Gbps Ethernet port; Motorola says it's certified by Comcast Xfinity |
| You have Xfinity Voice | NETGEAR CM2050V | Two phone ports and a 2.5 Gbps Ethernet port; requires an Xfinity Voice plan |
| X-Class plan (X-300 to X-2Gig) | Xfinity's gateway | Xfinity says owned modems aren't currently compatible with X-Class speeds |

## Should you buy your own modem at all?

Owning a modem used to be an easy way to drop a monthly rental fee. That math has changed for some customers. Xfinity's support page for using your own equipment, last updated September 2, 2026, says: "The latest Xfinity Internet plans include the Xfinity Gateway at no extra cost." If you're on one of those plans, a modem you buy won't save you a fee. You'd buy one for other reasons, such as wanting to run your own router without Xfinity's Wi-Fi in the middle.

There are also plans an owned modem can't serve. Xfinity's article on recently upgraded areas, last updated August 30, 2026, says X-Class Internet (X-300, X-500, X-Gig and X-2Gig) offers equal upload and download speeds, and that "customer-owned modems are not currently compatible with X-Class speeds."

Owning also shifts work to you. Xfinity lists keeping the device "updated and secure" and troubleshooting problems with it as the owner's responsibilities. Our guide to [buying your own router vs. using your provider's equipment](https://wifiweekly.com/guides/buy-your-own-router-vs-isp-equipment/) covers the wider trade-off.

## Check My Device Info first

Xfinity doesn't publish a model list on its support page. It says: "Before you buy a device, make sure it works with Xfinity services and supports your internet speed." It points customers to the My Device Info tool, which shows devices that work with your service. For Gigabit plans, it adds: "Your device must support Gigabit speeds."

That check matters more in upgraded areas. Xfinity says "the new upload speeds in enhanced markets are up to 5–10 times faster than before, ranging from 75–200 Mbps," but "currently, there are limited retail modems, eMTAs or gateways available in the marketplace" that support them. If you already own a modem, Xfinity says it "should work for service tier speeds available before the recent upgrade." In other words, an older approved modem may keep working but cap your upload speed below what your plan now offers.

Look up the exact model you plan to buy, not just the product family. A modem being sold as compatible with Xfinity doesn't tell you whether it's certified for the upgraded upload speeds at your address.

## The picks in detail

### ARRIS SURFboard SB8200: for plans up to 1 Gbps

The SB8200 is a DOCSIS 3.1 modem that ARRIS describes as "best for cable internet speed plans up to 1 Gbps." It has "Two 1 Gigabit Ethernet Ports," and ARRIS lists combined wired speeds of "Up to 2 Gbps," which only helps if your router can use both ports at once. It has no Wi-Fi and no phone ports, and it comes with a "2 Year Limited Warranty."

ARRIS says its SURFboard products are "tested and qualified by Cox, Comcast Xfinity, and Charter Spectrum." Its product page doesn't list the SB8200 as supporting next-generation upload tiers; that label appears on the S34 instead. If you're in an area Xfinity has upgraded, check My Device Info before you choose the SB8200.

Pick it if your plan is 1 Gbps or slower and you don't need Xfinity Voice. If you're unsure what DOCSIS 3.1 adds over 3.0, see our [DOCSIS 3.0 vs. 3.1 vs. 4.0 guide](https://wifiweekly.com/guides/docsis-3-0-vs-3-1-vs-4-0-cable-modem/).

### ARRIS SURFboard S34: for faster plans and upgraded upload

The S34 is a DOCSIS 3.1 modem with "One 2.5 Gigabit Ethernet Port and One 1 Gigabit Ethernet Port." ARRIS rates it for cable plans "Up to 2.5 Gbps (Next Gen Upstream)" and says it features "support for Next Generation Upload Speed service Tiers with switchable low to mid support." Like the SB8200, it has no Wi-Fi or phone ports and carries a "2 Year Limited Warranty." ARRIS announced it on September 5, 2024, at a "$219.00 MSRP"; we couldn't confirm today's retail price.

Pick it if your plan is above 1 Gbps or you want headroom for a faster tier. Confirm in My Device Info that the S34 is listed for your address and plan, since ARRIS's own page notes that "compatibility may vary by model and provider."

### Motorola MB8611: an alternative with a 2.5 Gbps port

Motorola's data sheet for the MB8611 lists DOCSIS 3.1 with "Up to 32 SCQAM (DOCSIS 3.0) or 2 OFDM (DOCSIS 3.1)" downstream channels and "One 10/100/1000/2500 Ethernet LAN port." It says the modem is "Certified by Comcast Xfinity® and other Internet Service Providers," and lists a two-year warranty. It "does not have telephone jacks," and it "does not have a built-in wireless router."

The data sheet's headline figures, "Up to 6,000 Mbps" down and "Up to 800 Mbps" up, describe what the modem's DOCSIS 3.1 hardware supports, not what you'll get. Your plan sets your speed, and the single 2.5 Gbps port caps what reaches your router. The data sheet doesn't say whether the MB8611 supports Xfinity's upgraded upload tiers, so check My Device Info.

### NETGEAR CM2050V: if you have Xfinity Voice

A regular cable modem can't carry Xfinity Voice. The CM2050V is a DOCSIS 3.1 modem with "two (2) telephone ports" and "One (1) LAN 2.5Gbps Gigabit Ethernet port." NETGEAR's page says it "Requires Xfinity® Voice Service Plan. Not compatible with any other ISP or fiber service provider" and that it "Will not work with any other voice service except XFINITY Voice." The same page also calls it "Compatible with all major US Cable Service Providers," which contradicts that. Treat it as an Xfinity-only device.

NETGEAR backs it with a "limited 1-year Hardware Warranty," half the length ARRIS and Motorola list for their modems. Its "up to 10Gbps" download figure is, in NETGEAR's own footnote, "the maximum data transfer rate in the DOCSIS® 3.1 standard," not a speed you'll see.

## What else you'll need

You'll need a router or mesh system: ARRIS and Motorola list no Wi-Fi on the SB8200, S34 and MB8611, and the CM2050V is sold as a modem, not a gateway. If your plan is faster than 1 Gbps, that router needs a WAN port faster than gigabit too, or the modem's 2.5 Gbps port won't help. Our guide to [whether you need a multi-gig router](https://wifiweekly.com/guides/do-you-need-a-multi-gig-router/) explains the port math, and our [best mesh Wi-Fi for gigabit internet](https://wifiweekly.com/guides/best-mesh-wifi-for-gigabit-internet/) covers what to pair with a 1 Gbps plan.

## Sources and verification

| Important claim | Source | Status |
|---|---|---|
| Device must work with Xfinity and support your speed; My Device Info lookup; Gigabit devices must support Gigabit; owner responsibilities; latest plans include the gateway at no extra cost | [Xfinity Support, updated Sept. 2, 2026](https://www.xfinity.com/support/internet/list-of-approved-cable-modems/) | Verified |
| Owned modems not compatible with X-Class; limited retail devices for enhanced upload; 75–200 Mbps upload in enhanced markets; owned devices work at pre-upgrade tiers | [Xfinity Support, updated Aug. 30, 2026](https://www.xfinity.com/support/articles/upgraded-areas-leased-equipment-required-for-upload-speeds) | Verified |
| SB8200: DOCSIS 3.1, best for plans up to 1 Gbps, two gigabit ports, no Wi-Fi or voice, 2-year warranty | [ARRIS SURFboard](https://www.surfboard.com/products/cable-modems/SB8200/) | Verified |
| S34: 2.5 Gbps + 1 Gbps ports, up to 2.5 Gbps plans, next-gen upload support, 2-year warranty | [ARRIS SURFboard](https://www.surfboard.com/products/cable-modems/S34/) | Verified |
| S34 announced Sept. 5, 2024, at $219 MSRP | [PR Newswire](https://www.prnewswire.com/news-releases/new-arris-surfboard-s34-docsis-3-1-cable-modem-delivers-fastest-internet-speeds-available-302239650.html) | Verified (launch MSRP, not a current price) |
| MB8611: 2.5 Gbps port, certified by Comcast Xfinity, no phone jacks or Wi-Fi, 2-year warranty | [Motorola data sheet (Cox-hosted)](https://www.cox.com/content/dam/cox/residential/support/internet/print_media/MotorolaMB8611_DataSheet.pdf) | Verified |
| CM2050V: two phone ports, 2.5 Gbps port, requires Xfinity Voice, 1-year warranty | [NETGEAR](https://www.netgear.com/home/wifi/modems/cm2050v/) | Qualified (NETGEAR's page contradicts itself on other providers) |


## Frequently asked questions

### Does Xfinity still charge to rent a modem?

Xfinity's support page for using your own equipment says "The latest Xfinity Internet plans include the Xfinity Gateway at no extra cost." Older plans may differ, so check your bill before assuming that owning a modem will save you money.

### Can I use my own modem with Xfinity X-Class internet?

Not currently. Xfinity's support article on upgraded areas says "customer-owned modems are not currently compatible with X-Class speeds." X-Class covers X-300, X-500, X-Gig and X-2Gig.

### Do I need a 2.5 Gbps Ethernet port?

Only for plans faster than about 1 Gbps. A gigabit Ethernet port tops out at 1 Gbps before overhead, which is why ARRIS rates the SB8200, with two gigabit ports, for plans up to 1 Gbps and the S34, with a 2.5 Gbps port, for plans up to 2.5 Gbps. Your router also needs a 2.5 Gbps WAN port to use it.

### Will my own modem give me Xfinity's faster upload speeds?

Only if it's certified for the upgraded network in your area. Xfinity says upload speeds in enhanced markets range from 75 to 200 Mbps, that limited retail devices support them, and that owned devices should work at the speeds available before the upgrade. Check your exact model in My Device Info.

### Does a cable modem include Wi-Fi?

The SB8200, S34 and MB8611 have no Wi-Fi, and NETGEAR sells the CM2050V as a cable modem, not a gateway. You'll need a separate router or mesh system plugged into the modem's Ethernet port.

## Sources

- Using your own modem, router, or gateway with Xfinity, Xfinity Support: https://www.xfinity.com/support/internet/list-of-approved-cable-modems/
- Devices certified for enhanced speeds required in recently upgraded areas, Xfinity Support: https://www.xfinity.com/support/articles/upgraded-areas-leased-equipment-required-for-upload-speeds
- SB8200 SURFboard DOCSIS 3.1 Cable Modem, ARRIS SURFboard: https://www.surfboard.com/products/cable-modems/SB8200/
- S34 SURFboard DOCSIS 3.1 Cable Modem, ARRIS SURFboard: https://www.surfboard.com/products/cable-modems/S34/
- New ARRIS SURFboard S34 DOCSIS 3.1 Cable Modem Delivers Fastest Internet Speeds Available, ARRIS via PR Newswire: https://www.prnewswire.com/news-releases/new-arris-surfboard-s34-docsis-3-1-cable-modem-delivers-fastest-internet-speeds-available-302239650.html
- Motorola MB8611 data sheet, Motorola (hosted by Cox): https://www.cox.com/content/dam/cox/residential/support/internet/print_media/MotorolaMB8611_DataSheet.pdf
- Nighthawk Multi-Gig 2.5Gbps Cable Modem for Xfinity Voice (CM2050V), NETGEAR: https://www.netgear.com/home/wifi/modems/cm2050v/