ApprovedModemwhat your ISP actually allows

Xfinity (Comcast): can you use your own modem?

Own modem allowed — approved list published

Yes — Xfinity (Comcast) allows customer-owned modems and publishes its own approved-device list. It names devices including ARRIS Surfboard S33 and ARRIS Surfboard SBG8300. Buy from that list — anything off it may not activate. Every detail below is quoted from Xfinity (Comcast)'s own page, last checked 2026-08-25.

Connection
cable (DOCSIS). Article carves out an exception …
Verified
2026-08-25
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Links go to an Amazon search — as an Amazon Associate we earn from qualifying purchases, at no extra cost to you. They never change what Xfinity (Comcast) permits: check the model against their own page below before ordering.

  1. Your modemyou buy it, or you rent it
  2. Your ISP's networkthey decide what connects
  3. The internetthe part you actually want
Your equipment has to satisfy Xfinity (Comcast) before it reaches the internet at all — which is why their published rule, not a retailer's compatibility claim, is the one that decides.

Which modems does Xfinity (Comcast) approve?

Xfinity (Comcast) names these models on its own page. They are the exact make and model strings published there as of 2026-08-25 — a sample of the list, not necessarily all of it.

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Browse compatible cable modems on Amazon →

Amazon search · affiliate link — we may earn a commission from qualifying purchases, at no extra cost to you.

Can I use my own modem with Xfinity (Comcast)?

Yes, with a restriction: the device has to appear on Xfinity (Comcast)'s published approved list. In their words: "You can buy and use your own modem, router, or gateway instead of renting one from Xfinity." FAQ: "Can I use my own modem? Yes. Make sure it's certified and supports your internet speed."

What DOCSIS version does Xfinity (Comcast) require?

No minimum stated as a requirement. The list's per-device DOCSIS column contains only "DOCSIS 3.0" and "DOCSIS 3.1" values — both appear as compatible.

Do Xfinity (Comcast)'s requirements change with my speed tier?

Each device row states a "Wired Download Speed" cap, e.g. "Up to 2.33 Gbps", "Up to 941 Mbps", "Up to 373 Mbps" — buy to your tier. Policy article FAQ: "Can I use my own device with Gigabit Internet? Yes, if it's certified for Gigabit speeds."

Can I use my own equipment with Xfinity (Comcast) phone or voice service?

Permitted. "You can buy and use your own modem, router, or gateway instead of renting one from Xfinity." The list has a "Built-in WiFi" Yes/No column and a separate "Voice Telephone enabled" column; gateways (Yes/WiFi) are included, e.g. SBG8300, G36, CBR750. Caveat from the article: "Most modems need a router to use WiFi or support services like Xfinity Home."

What does Xfinity (Comcast) not allow?

"Devices not shown on this list are either incompatible with the Xfinity network or no longer supported by the device manufacturer." Also: "Can I use Xfinity Prepaid equipment with Xfinity Internet services? No. Xfinity Prepaid equipment doesn't work with Xfinity Internet services." And: "If a device isn't supported, it won't work with Xfinity."

Two boxes

  1. Modemtalks to the ISP line
  2. Routermakes the Wi-Fi

One box — a “gateway”

  1. Modem + routerone unit does both jobs
Xfinity (Comcast) treats the modem and the Wi-Fi router as separate questions. Read their wording below before assuming one box covers both.

Where does this information come from?

Every statement on this page is quoted from Xfinity (Comcast)'s own published page:

Last verified 2026-08-25. Approved lists and equipment policies change without notice — re-check the source above before you buy.

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