Best cable modem (stop renting from your ISP)

Most people pay their ISP about $15 a month to rent a modem — roughly $180 a year, forever. A good DOCSIS 3.1 modem costs a fraction of that and is usually paid off in well under a year. Here's what actually matters, then picks in three tiers.

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Bargain get-it-done · Intermediate prosumer / IT generalist · Pro daily-driver for techs

What to look for

DOCSIS 3.1, not 3.0. DOCSIS 3.1 is the floor in 2026 — it's faster, more efficient, and future-proofs you for plan upgrades. A cheap 3.0 modem can save a few dollars today and cap you tomorrow.
Channel bonding. More bonded channels (e.g. 32×8 on 3.0, or full OFDM on 3.1) means more headroom on a busy node. On 3.1, OFDM is what carries gigabit plans — make sure it's there.
ISP compatibility — check the approved list first. A modem only works if your provider certifies it. Confirm it's on the approved list for Comcast/Xfinity, Spectrum or Cox before you buy — an unapproved modem simply won't activate.
Modem-only vs modem+router combo. A modem-only unit lets you pair your own router and upgrade each separately — the better long-term choice. A combo (gateway) is one box but ties the two together. Already have a good router? Buy modem-only.
Match it to your plan speed. A gigabit plan needs a gigabit-class modem; a multi-gig plan needs a 2.5G modem and port. Buying more than your plan delivers is wasted money until you upgrade.
It ends the rental fee. At ~$15/mo, owning your modem typically pays for itself in months — every month after that is pure savings, and the modem is yours.

Stand-alone cable modem

A modem-only box you pair with your own router — the right call for most homes that want to drop the rental fee and keep upgrade flexibility. Match the tier to your internet plan speed.

Bargain Motorola MB7621 / Netgear CM class (DOCSIS 3.1) — solid, widely approved, perfect for plans up to a few hundred Mbps. Find it →

Intermediate Motorola MB8611 / Arris S33 (gigabit DOCSIS 3.1) — full OFDM and a 2.5G port, ready for gigabit plans and a faster router. Find it →

Pro Netgear CM3000 / Arris S34 (2.5G multi-gig DOCSIS 3.1) — multi-gig DOCSIS 3.1 for the fastest cable plans and headroom to spare. Find it →

Before you order, look up the exact model on your ISP's approved-device list (Comcast/Xfinity, Spectrum or Cox). On a multi-gig plan? Make sure the modem's port and your router's WAN port both match — and keep a known-good Cat6/6a patch cable on hand so the cable isn't the bottleneck.

New modem in? Make sure it actually fixed the speed.

After you swap modems, you want proof the dropouts and slow speeds are gone — not a guess. Acutis Go is free: run it on the machine that was struggling and watch the latency, packet loss and throughput so you know the new modem did the job.

Download Acutis Go — free

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