Last updated: August 2026
Key Takeaways
- A DOCSIS 3.1 modem with a 2.5 Gigabit Ethernet port is still the right purchase in 2026. Retail DOCSIS 4.0 modems remain scarce, and most cable networks are optimized for 3.1.
- Match the modem to your speed tier, then confirm the exact model on your ISP's official approved list before buying. An unapproved modem will not activate.
- Owning your modem eliminates rental fees on legacy plans and gives you hardware control on newer plans that bundle the gateway into the price.
The best DOCSIS 3.1 modem for most people in 2026 is the Arris SURFboard S34. It supports multi-gig download speeds, has a 2.5 Gigabit Ethernet port, and works with the faster upload tiers Xfinity, Cox, and Spectrum are rolling out. The Hitron CODA56 delivers most of that performance for less, and the Arris SB8200 remains the budget pick for standard gigabit plans.
Every modem below is a cable modem. None of them work with fiber, DSL, or satellite service, and most do not support bundled voice plans. Fiber providers like AT&T Fiber and Verizon Fios use an ONT instead of a modem. Confirm your provider and speed tier before ordering.
Why DOCSIS 3.1 Is Still the Right Buy in 2026
DOCSIS 3.1 remains the standard for customer-owned cable modems in 2026. The next generation, DOCSIS 4.0, is live in a growing number of markets, but nearly all DOCSIS 4.0 service today runs on ISP-issued gateways, and retail DOCSIS 4.0 modems are only expected to reach shelves in the second half of 2026. Our DOCSIS 4.0 explainer covers the technology, and our rollout tracker by provider shows where it is actually available.
The money math has also changed, and it is worth stating honestly. On legacy plans, gateway rental still costs real money: as of mid-2026, Xfinity charges $15 to $25 per month on plans sold before mid-2025, Cox charges $15 for its Panoramic gateway, and Spectrum adds a $10 monthly fee for its Advanced WiFi, per each provider's published equipment pricing. On those plans, a modem you own pays for itself within the first year. Newer bundled plans, like Xfinity's Everyday Pricing, fold the gateway into the monthly price, so the argument there is different: owning your equipment is about control, privacy, and choosing better hardware than the default box, not a line-item deletion on the bill.
The Best DOCSIS 3.1 Modems of 2026
1. Arris SURFboard S34: Best Overall
The S34 is the top pick for 2026. It handles plans up to 2.5 Gbps, includes both a 2.5 Gigabit and a 1 Gigabit Ethernet port, and supports mid-split technology, which unlocks the faster upload tiers on plans like Xfinity Next-Gen. It runs a stable Broadcom chipset, sets up in minutes through the SURFboard Central app, and is certified for Xfinity, Cox, and Spectrum. One modem that covers every current cable plan.
Check Availability: Arris SURFboard S34
2. Arris SURFboard S33: Best Runner-Up
The S33 is nearly identical to the S34 without the enhanced upload support, which makes it the smart buy where Next-Gen upload upgrades have not arrived. Same 2.5 Gigabit port, same stable Broadcom chipset, usually a lower price. It is certified for Xfinity, Cox, and Spectrum and has a long track record of steady, low-latency performance.
Check Availability: Arris SURFboard S33
3. Netgear Nighthawk CM3000: Best for Fast Uploads
The CM3000 is built for households that upload as much as they download: content creators, remote workers on constant video calls, anyone pushing large backups to the cloud. It supports both mid-split and high-split configurations, handles download plans up to 2.5 Gbps, and includes a 2.5 Gigabit port. It costs more than most modems here, but nothing on this list is better prepared for the upload upgrades Xfinity and Cox are rolling out.
Check Availability: Netgear Nighthawk CM3000
4. Hitron CODA56: Best Value
The CODA56 gives you a 2.5 Gigabit port and mid-split capability at a price that undercuts the bigger brands. It supports plans up to about 2.3 Gbps and is certified for Xfinity, Spectrum, and Cox. It skips the extras, and for anyone on a gigabit plan who wants the most performance per dollar, it is the smartest buy of 2026.
Check Availability: Hitron CODA56
5. Motorola B12: Best Compact Multi-Gig
New to this list for 2026, the B12 is Motorola's direct successor to the popular MB8611. It pairs DOCSIS 3.1 with a 2.5 Gigabit Ethernet port, reaches downstream speeds just below 2,500 Mbps with uploads up to 800 Mbps where supported, and fits a smaller footprint than nearly anything else in its class. It is approved for Xfinity, Cox, Spectrum, RCN, and Astound, and it carries a 2-year warranty, which is longer than most of this list.
Check Availability: Motorola B12
6. Motorola MB8611: Proven Low-Latency Pick
The MB8611 pairs a 2.5 Gigabit Ethernet port with a strong record of flat, reliable latency during gaming, streaming, and video calls. It supports downloads just under 2.5 Gbps and uploads up to 800 Mbps where supported, and it is approved for Xfinity, Cox, and Spectrum. The B12 above is its successor, but while the MB8611 is available it remains a dependable, well-supported choice.
Check Availability: Motorola MB8611
7. Netgear Nighthawk CM2500: Best for Xfinity Upload Tiers
The CM2500 is a mid/high-split modem designed around the newer upload-focused plans, including Xfinity tiers with 100 Mbps uploads. It reaches 2 Gbps downloads by combining its two 1 Gigabit ports through link aggregation, so pair it with a router that supports that feature to get full speed. Not compatible with Xfinity Voice plans.
Check Availability: Netgear Nighthawk CM2500
8. Arris SURFboard SB8200: Best Budget Pick for Gigabit Plans
The SB8200 is the classic DOCSIS 3.1 modem: widely deployed, extremely stable, and compatible with every major cable ISP. It has two 1 Gigabit ports and no multi-gig or mid-split support, which makes it the right choice for standard plans from 300 to 1,000 Mbps where you simply want reliability at the lowest cost.
Check Availability: Arris SURFboard SB8200
9. Motorola MB8600: Budget Classic
The MB8600 is another proven budget option for gigabit-and-under plans. It runs a secure Broadcom chipset, holds latency down under load, and works with Xfinity, Cox, and other major providers. If you see it priced below the SB8200, grab it.
Check Availability: Motorola MB8600
10. Arris SURFboard G34: Best Modem-Router Combo
Want one box instead of two? The G34 combines a DOCSIS 3.1 modem with a Wi-Fi 6 router, delivering wireless speeds up to 3 Gbps and support for cable plans up to 1 Gbps. It is compatible with Xfinity, Cox, and Spectrum, and setup takes minutes through the SURFboard Central app. A combo means fewer cables, one outlet, and one device to manage.
Check Availability: Arris SURFboard G34
11. Arris DG3450 (Refurbished): Best Combo Value for Spectrum
The DG3450 is the budget path to a one-box setup on Spectrum: a DOCSIS 3.1 modem and dual-band Wi-Fi router in a single gateway, with four Gigabit Ethernet ports and MoCA 2.0 support for stable whole-home coax networking. Because it replaces both the modem and the router, it also replaces Spectrum's $10 per month Advanced WiFi fee with equipment you own. This is a Spectrum-specific pick: it is not the right buy for Xfinity households, so confirm your provider before ordering. We stock professionally refurbished units, each tested in the US and backed by a 90-day warranty.
Check Availability: Arris DG3450 (Refurbished)
Comparison Table: Best DOCSIS 3.1 Modems of 2026
| Model | Best For | Max Plan Speed | 2.5G Port | Next Gen Uploads |
|---|---|---|---|---|
| Arris S34 | Overall | 2.5 Gbps | Yes | Yes (mid-split) |
| Arris S33 | Runner-up | 2.5 Gbps | Yes | No |
| Netgear CM3000 | Heavy uploads | 2.5 Gbps | Yes | Yes (mid/high-split) |
| Hitron CODA56 | Value | 2.3 Gbps | Yes | Yes (mid-split) |
| Motorola B12 | Compact multi-gig | 2.5 Gbps | Yes | No |
| Motorola MB8611 | Low latency | 2.5 Gbps | Yes | No |
| Netgear CM2500 | Xfinity upload tiers | 2 Gbps (link aggregation) | No (2x 1G) | Yes (mid/high-split) |
| Arris SB8200 | Budget gigabit | 1 Gbps | No | No |
| Motorola MB8600 | Budget classic | 1 Gbps | No | No |
| Arris G34 | Modem-router combo | 1 Gbps | No | No |
| Arris DG3450 (Refurb) | Spectrum combo value | 1 Gbps | No | No |
Next Gen Uploads means the modem supports mid-split or high-split configurations where the ISP has upgraded its network. Confirm your exact model on your provider's approved list before buying.
How to Choose a DOCSIS 3.1 Modem
Match the modem to your plan speed
Buying a multi-gig modem for a 300 Mbps plan wastes money, and buying a gigabit modem for a 2 Gbps plan wastes speed. Check your bill for your plan tier, then pick the cheapest modem on this list that comfortably covers it.
Check for a 2.5 Gigabit Ethernet port
Gigabit plans are often over-provisioned, meaning your real speed can exceed 1,000 Mbps. A standard 1 Gigabit port caps you around 940 Mbps in practice. If your plan is 1 Gbps or faster, a 2.5 Gigabit port ensures you receive everything you pay for.
Look for mid-split support if your ISP offers faster uploads
Cable uploads sat around 35 Mbps for years. Mid-split and high-split technology raises that to 100 Mbps or more where ISPs have upgraded their networks. If your provider advertises enhanced or Next-Gen upload speeds, choose the S34, CM3000, CM2500, or CODA56.
Know your ISP's limits on customer-owned equipment
Spectrum only authorizes retail modems on tiers up to 1 Gig; its 2 Gig plan requires Spectrum-provided equipment. Spectrum also charges $10 per month for its Advanced WiFi router, which is why a combo like the DG3450 pays off fastest there. Cox supplies its own hardware for bundled voice service. Rules like these change by provider and by plan, which is one more reason the approved list, not the spec sheet, gets the final word.
Remember these are modems, not routers
Except for the G34 combo, every modem here needs a separate Wi-Fi router to create a wireless network. If you already own a good router, a standalone modem is the better setup. Browse our wireless router collection to pair one up.
Check Your ISP's Approved List Before You Buy
A cable modem only works if your provider will activate it, and each ISP maintains its own certified device list that changes several times a year. We audit those lists against this guide regularly. Before ordering, confirm your exact model on our Xfinity approved modem list, Cox approved modem list, or Spectrum approved modem list, each of which links the provider's official page. Cox, for example, publishes its authoritative list at cox.com, and only models on it will provision.
Frequently Asked Questions
Do I need a DOCSIS 3.1 modem?
If you are buying a cable modem in 2026, yes. Xfinity, Spectrum, and Cox are actively retiring DOCSIS 3.0 hardware from their approved lists, and Spectrum ends DOCSIS 3.0 support entirely on October 28, 2026. A DOCSIS 3.1 modem works on every current cable plan and will not need replacing when your ISP finishes the transition.
Are DOCSIS 3.1 modems backwards compatible?
Yes. Every DOCSIS 3.1 modem is fully backwards compatible with DOCSIS 3.0 networks and plans. If your area has not been upgraded yet, a 3.1 modem simply runs at 3.0 speeds until the network catches up, so there is no downside to buying 3.1 now.
Is a DOCSIS 3.1 modem worth it?
Yes, for almost everyone. The price gap between DOCSIS 3.0 and 3.1 modems has nearly closed, and a 3.1 modem eliminates rental fees while staying compatible through your ISP's network upgrades. The only exception is a plan you know you are canceling within a few months.
Is DOCSIS 3.1 obsolete in 2026?
No. DOCSIS 3.1 remains the standard for customer-owned cable modems in 2026. DOCSIS 4.0 service is expanding, but it runs almost entirely on ISP-issued gateways today, and retail DOCSIS 4.0 modems are only expected in the second half of 2026. Our DOCSIS 4.0 modem guide tracks that retail rollout.
What is the difference between DOCSIS 3.0 and DOCSIS 3.1?
DOCSIS 3.1 is roughly ten times faster than DOCSIS 3.0, with lower latency and better efficiency. Major ISPs are actively retiring DOCSIS 3.0 hardware; Xfinity removed roughly 30 older DOCSIS 3.0 models from its approved list in April 2026 alone. For any new purchase, 3.1 is the minimum standard.
Which DOCSIS 3.1 modem is best for Xfinity?
The Arris SURFboard S34 is the best DOCSIS 3.1 modem for Xfinity in 2026 because it supports Next-Gen upload tiers. For standard Xfinity gigabit plans, the Arris S33 or Hitron CODA56 also work well. Confirm your pick on our Xfinity approved modem list before buying.
Do I still need a router with a DOCSIS 3.1 modem?
Yes, unless you buy a combo unit like the Arris G34. A modem connects your home to your ISP, and a router creates the Wi-Fi network your devices use. Standalone modems have no Wi-Fi built in.
How much money does buying your own modem save?
On legacy plans, most cable providers charge $10 to $25 per month for equipment, or $120 to $300 per year, so an owned modem typically pays for itself within a year. On newer bundled plans that include the gateway, the savings are smaller or zero, and the case for ownership is control, privacy, and better hardware instead.
What is a mid-split modem?
A mid-split modem dedicates more of the cable frequency spectrum to uploads, raising upload speeds from around 35 Mbps to 100 to 200 Mbps on supported networks. High-split goes further, up to 1 Gbps in some areas. You only benefit if your ISP has upgraded your neighborhood.
Are refurbished modems worth buying?
Yes, when they are professionally tested and warranty-backed. A refurbished DOCSIS 3.1 modem delivers identical performance to a new unit at a lower price, and it keeps working hardware out of landfills. Every unit in our DOCSIS 3.1 modem collection, including the DG3450 gateway above, is tested in the US and covered by a 90-day warranty.
Do I need a special modem for gaming?
No. Every DOCSIS 3.1 modem is required by the CableLabs specification to include anti-bufferbloat Active Queue Management, documented in RFC 8034, so the machinery for low latency ships in all of them; whether it runs is governed by your ISP's configuration. Our gaming modem guide covers what actually moves your ping.
