What Is DOCSIS 4.0? Speeds, Rollout Timeline, and Everything You Need to Know (2026)
Last updated: March 2026
Key Takeaways
- DOCSIS 4.0 supports up to 10 Gbps downstream and 6 Gbps upstream — a massive improvement in upload capacity that enables true symmetrical multi-gigabit cable internet for the first time.
- Consumer rollout is underway but limited. Comcast (Xfinity) is leading deployment across ten-plus U.S. markets, with Mediacom and Charter following. Retail DOCSIS 4.0 modems are expected to hit shelves in 2026, though most areas still run on DOCSIS 3.1.
- DOCSIS 4.0 does not replace fiber, but it closes the gap significantly. For the millions of homes without access to fiber-to-the-home, DOCSIS 4.0 delivers fiber-competitive speeds over existing coaxial cable infrastructure.
What Is DOCSIS 4.0?
DOCSIS stands for Data Over Cable Service Interface Specification. It is the international standard that governs how data travels over coaxial cable networks — the same hybrid fiber-coax (HFC) infrastructure that delivers cable television and internet to over 90% of American households.
DOCSIS 4.0 is the latest version of this standard, developed by CableLabs and first published in 2020. It represents the biggest architectural upgrade to cable internet in over a decade, with two headline capabilities: symmetrical multi-gigabit speeds and full duplex communication.
At its core, DOCSIS 4.0 supports up to 10 Gbps downstream and 6 Gbps upstream. The upstream improvement is the real story here. Previous DOCSIS versions maxed out at 1.5 Gbps upstream (DOCSIS 3.1) and just 200 Mbps upstream (DOCSIS 3.0). With remote work, cloud storage, live streaming, and video conferencing now standard in most households, upstream bandwidth has become far more important than it was when earlier DOCSIS versions were designed.
DOCSIS 4.0 achieves these speeds through two complementary technologies:
Full Duplex DOCSIS (FDX) allows data to be transmitted upstream and downstream simultaneously over the same spectrum. This is the approach Comcast is pursuing aggressively across its network.
Extended Spectrum DOCSIS (ESD), sometimes called Frequency Division Duplex (FDD), expands the usable frequency range up to 1.8 GHz. This gives operators more bandwidth to work with without requiring the same level of infrastructure changes as FDX. ESD tends to be more practical for rural operators with longer cable runs.
Cable operators choose one approach based on their network topology, though Broadcom has developed unified chipsets that support both FDX and ESD in a single device — giving providers flexibility as they upgrade.
How DOCSIS 4.0 Compares to Previous Versions
Understanding where DOCSIS 4.0 fits requires a quick look at the evolution of the standard.
DOCSIS 3.0 was released in 2006 and introduced channel bonding, which allowed modems to combine multiple channels for faster throughput. It supports theoretical speeds of up to 1 Gbps downstream and 200 Mbps upstream. In practice, a well-provisioned DOCSIS 3.0 modem with a 32x8 channel configuration handles plans up to about 800 Mbps. DOCSIS 3.0 was the backbone of cable internet for roughly a decade and remains in use on some networks today, though most major ISPs have moved on.
DOCSIS 3.1 arrived in 2013 and brought OFDM (Orthogonal Frequency Division Multiplexing) to cable networks, dramatically improving spectral efficiency. It increased theoretical capacity to 10 Gbps downstream and 1.5 Gbps upstream. In the real world, DOCSIS 3.1 is what powers most gigabit and multi-gigabit cable plans available today. As of late 2024, 98% of U.S. cable households had access to 1+ Gbps downstream tiers over HFC networks running DOCSIS 3.1.
DOCSIS 4.0 builds on the OFDM foundation of 3.1 but adds full duplex communication and expanded spectrum. The result is up to 10 Gbps downstream and 6 Gbps upstream — quadrupling the upload capacity of DOCSIS 3.1. It also carries forward Low Latency DOCSIS (LLD), which was introduced in 3.1, to reduce lag for latency-sensitive applications like gaming and video conferencing.
Here is a simplified comparison:
| Specification | DOCSIS 3.0 | DOCSIS 3.1 | DOCSIS 4.0 |
|---|---|---|---|
| Release Year | 2006 | 2013 | 2020 |
| Max Downstream | ~1 Gbps | 10 Gbps | 10 Gbps |
| Max Upstream | 200 Mbps | 1.5 Gbps | 6 Gbps |
| Key Technology | Channel Bonding | OFDM / OFDMA | FDX + ESD, OFDM |
| Symmetrical Speeds | No | Limited | Yes |
| Low Latency Support | No | Yes (LLD) | Yes (LLD) |
| Spectrum Range | Up to ~1 GHz | Up to ~1.2 GHz | Up to 1.8 GHz |
When Will DOCSIS 4.0 Be Available to Consumers?
DOCSIS 4.0 is already live in select markets, but widespread consumer availability is still developing.
Comcast (Xfinity) has been the clear frontrunner. The company launched the world's first commercial DOCSIS 4.0 service in early 2024, starting with neighborhoods in Colorado Springs, Atlanta, and Philadelphia. By late 2024, Comcast had expanded to ten markets — adding Sacramento, Denver, Seattle, Augusta, Miami, and Pittsburgh — covering more than one million homes. Comcast has targeted symmetrical speeds of 3 Gbps by 2025 and 5 Gbps by 2026 on its DOCSIS 4.0 network.
Comcast is also field-testing the XB10, a DOCSIS 4.0 gateway with Wi-Fi 7, along with the XB10u model that uses Broadcom's unified FDX/ESD chipset.
Charter Communications (Spectrum) has taken a more gradual approach, completing high-split upgrades across about 15% of its footprint as a first phase. Charter's full DOCSIS 4.0 deployment timeline has slipped from an original 2025 target to 2026, partly due to equipment certification delays. If Charter's proposed merger with Cox Communications is approved, the company has indicated it will accelerate DOCSIS 4.0 upgrades in Cox's markets.
Mediacom launched its first commercial DOCSIS 4.0 deployment in September 2025, expanding into its Illinois market using equipment from ATX, Harmonic, and Hitron.
In Canada, Rogers Communications announced a partnership with Comcast in late 2024 to bring DOCSIS 4.0 technology to Canadian subscribers, with trials underway in Calgary.
For most consumers, the practical timeline looks like this: if you are in a Comcast market, you may already have access or will within the next year. For Spectrum, Cox, and other cable subscribers, broader availability is more likely in late 2026 and into 2027. Smaller and regional operators are still in the evaluation and lab-testing phase.
Which Internet Providers Currently Support DOCSIS 4.0?
As of early 2026, the list of operators with commercial DOCSIS 4.0 deployments is short but growing:
- Comcast (Xfinity) — Live in 10+ U.S. markets with active expansion underway. The most advanced consumer-facing DOCSIS 4.0 deployment in the world.
- Mediacom — Commercially deployed in select markets starting September 2025.
- Charter (Spectrum) — Network upgrades in progress. Full DOCSIS 4.0 rollout expected to ramp through 2026.
- Rogers (Canada) — Trialing DOCSIS 4.0 with Comcast partnership; broader rollout timing not yet confirmed.
According to CableLabs, all of its member operators have some form of DOCSIS 4.0 deployment or testing in process. Other cable providers such as Cox, Midco, and Cogeco are expected to follow as equipment reaches volume production and pricing comes down.
It is worth noting that some operators are pursuing an intermediate step called DOCSIS 3.1+, which uses DOCSIS 4.0 modems on upgraded 3.1 infrastructure to achieve multi-gigabit downstream speeds without the full plant upgrade that DOCSIS 4.0 requires. This approach lets operators deliver faster billboard speeds at lower cost, buying time before a complete 4.0 deployment.
Will DOCSIS 4.0 Replace Fiber?
No. DOCSIS 4.0 and fiber-to-the-home (FTTH) are fundamentally different technologies, and each has its own advantages.
Fiber delivers data over glass strands using light, with virtually unlimited theoretical bandwidth, extremely low latency, and no signal degradation over distance. Current residential fiber deployments commonly offer symmetrical speeds of 1 to 10 Gbps, and the underlying technology can scale much further.
DOCSIS 4.0 delivers data over existing coaxial copper cable using radio frequencies. While it can now match fiber's multi-gigabit downstream speeds and come close on the upstream side, it still operates over a shared medium that is more susceptible to congestion, signal loss, and noise interference — especially over longer cable runs.
That said, DOCSIS 4.0 has one enormous practical advantage: infrastructure already exists. Cable networks reach the vast majority of American homes. Deploying DOCSIS 4.0 over this existing plant is significantly faster and cheaper than trenching new fiber to every doorstep. For providers, DOCSIS 4.0 is a way to deliver competitive speeds without the capital expenditure of a full fiber overbuild.
For consumers, the takeaway is straightforward. If fiber is available at your address, it remains the gold standard for raw performance and reliability. If it is not, DOCSIS 4.0 will deliver a dramatic improvement over what cable internet has offered in the past — particularly on the upload side. The two technologies will coexist for the foreseeable future, and many cable operators are deploying both fiber and DOCSIS 4.0 across different parts of their footprints.
CableLabs is already researching extensions beyond DOCSIS 4.0 that could push cable spectrum to 3 GHz (targeting 25 Gbps) and even 6 GHz (targeting 50 Gbps), ensuring that HFC networks remain competitive with fiber for years to come.
Is DOCSIS 3.0 Outdated?
For most practical purposes, yes. DOCSIS 3.0 is aging technology at this point.
Released in 2006, DOCSIS 3.0 served the industry well for over a decade, but its limitations are increasingly apparent in 2026. Its maximum upstream speed of 200 Mbps is a hard ceiling, and most DOCSIS 3.0 modems in the field top out at plans around 600–800 Mbps downstream. It also lacks the OFDM efficiency improvements, low latency features, and enhanced security that came with DOCSIS 3.1.
Most major ISPs — including Xfinity, Spectrum, and Cox — have shifted their networks to DOCSIS 3.1. Some, like Cox, have actively pushed subscribers to upgrade from 3.0 modems, limiting speeds on older hardware to encourage the transition. If you are still using a DOCSIS 3.0 modem and paying for a plan above 300–400 Mbps, you are almost certainly not getting the speeds you are paying for.
DOCSIS 3.0 modems will continue to function on most networks for now — DOCSIS is backward compatible — but you will not benefit from the speed, latency, or security improvements available with newer standards. If you are shopping for a modem today, there is no reason to buy a DOCSIS 3.0 device. A DOCSIS 3.1 modem is the minimum you should consider, and it will serve you well until DOCSIS 4.0 modems become widely available at retail.
Are DOCSIS 4.0 Modems Available to Buy?
As of early 2026, DOCSIS 4.0 modems are not yet widely available at retail. The modems currently in use on DOCSIS 4.0 networks are primarily ISP-provided equipment — Comcast, for example, deploys its own proprietary gateways (such as the XB10) to subscribers in DOCSIS 4.0 markets.
On the manufacturing side, companies like Hitron have announced DOCSIS 4.0 modem hardware such as the CODA60, which is designed for operator deployment and supports an upgrade path from DOCSIS 3.1 to 4.0. However, these are not yet available for direct consumer purchase through retailers like Amazon or Best Buy.
Industry analysts expect consumer-grade DOCSIS 4.0 modems from brands like ARRIS/Motorola, NETGEAR, and Hitron to begin appearing on retail shelves in mid-to-late 2026, with pricing likely in the $150–$250 range for early models. Prices should come down over time as production scales and more ISPs support the standard.
Recommended DOCSIS 3.1 Modems While You Wait
Until DOCSIS 4.0 modems are available at retail, a high-quality DOCSIS 3.1 modem remains the best investment for most cable internet subscribers. These models are widely recommended and compatible with major ISPs including Xfinity, Spectrum, and Cox:
ARRIS S33 — A dedicated DOCSIS 3.1 modem with a 2.5 GbE port, supporting plans up to 2.5 Gbps. Widely regarded as the gold standard for standalone cable modems in 2026. Stable Broadcom chipset, no built-in Wi-Fi (pair with your own router).
Motorola MB8611 — Another excellent DOCSIS 3.1 standalone modem with a 2.5 GbE port. Supports plans up to 2.5 Gbps. Compatible with Xfinity, Cox, and Spectrum.
Shop Motorola MB8611 on ModemGuides
NETGEAR CM2000 — A DOCSIS 3.1 modem with a 2.5 GbE port, supporting multi-gig plans. Compatible with most major cable ISPs.
Shop NETGEAR CM2000 on ModemGuides
Hitron CODA56 — A DOCSIS 3.1 modem with 2.5 GbE, designed for speed and reliability. A solid choice if your ISP supports it.
Shop Hitron CODA56 on ModemGuides
All of these modems will continue to work on DOCSIS 4.0 networks thanks to backward compatibility, though you will need a DOCSIS 4.0 modem to take advantage of the full speeds once your ISP enables the new standard.
Frequently Asked Questions
What does DOCSIS stand for?
DOCSIS stands for Data Over Cable Service Interface Specification. It is the technical standard that enables high-speed internet over cable television networks. It was originally developed by CableLabs in the 1990s.
Do I need a new modem for DOCSIS 4.0?
Yes. DOCSIS 4.0 requires a new modem that supports the standard. Your current DOCSIS 3.1 modem will continue to work on upgraded networks, but it will not deliver DOCSIS 4.0 speeds. When your ISP begins supporting 4.0 in your area, you will need to either purchase a compatible modem or use one provided by your ISP.
Is DOCSIS 4.0 backward compatible?
Yes. DOCSIS 4.0 modems are backward compatible with DOCSIS 3.1 networks. This means you could buy a DOCSIS 4.0 modem when they become available at retail and use it on your current 3.1 network, then benefit from the faster speeds when your ISP upgrades. Older DOCSIS 3.0 modems will also continue to work on 4.0 networks, but at their original, slower speeds.
Will DOCSIS 4.0 make my internet faster right away?
Only if your ISP has deployed DOCSIS 4.0 in your area and you have a compatible modem. The speeds you experience also depend on the plan tier you subscribe to. Having a DOCSIS 4.0 modem on a 3.1 network will not give you 4.0 speeds — both sides of the connection must support the new standard.
How much will DOCSIS 4.0 modems cost?
Based on historical pricing patterns, early retail DOCSIS 4.0 modems are expected to cost between $150 and $250. Prices will likely decrease over time as more manufacturers enter the market. Alternatively, many subscribers will receive DOCSIS 4.0 equipment through their ISP's rental program, typically at $10–$15 per month.
Can I use a DOCSIS 4.0 modem with fiber internet?
No. Cable modems and fiber connections use completely different technologies. DOCSIS modems work over coaxial cable, while fiber internet uses fiber-optic cable and a different type of terminal device (typically an ONT). They are not interchangeable.
Is DOCSIS 4.0 better than fiber?
Fiber still has the edge in raw performance, latency, and long-term scalability. However, DOCSIS 4.0 narrows the gap significantly — particularly in download speeds. For most consumers, the difference in everyday use will be minimal. The main advantage of fiber remains its symmetrical speed consistency and lower latency, while DOCSIS 4.0's advantage is that it runs over infrastructure that already reaches most homes.
Should I buy a DOCSIS 3.1 modem now or wait for DOCSIS 4.0?
If your current modem is underperforming or you are on a DOCSIS 3.0 device, upgrading to a DOCSIS 3.1 modem now is a smart move. Most consumers will not have access to DOCSIS 4.0 service for at least another year, and a good 3.1 modem with a 2.5 GbE port will serve you well in the meantime. When 4.0 modems hit retail and your ISP supports the standard, you can upgrade then.
What is DOCSIS 3.1+ (DOCSIS 3.1 Plus)?
DOCSIS 3.1+ is an industry term for a new class of DOCSIS 3.1 modems that support additional OFDM channels (four or more), enabling higher downstream speeds on existing 3.1 infrastructure. Some operators are deploying DOCSIS 4.0 modems on 3.1 networks to achieve similar downstream improvements without a full plant upgrade. It serves as a bridge technology while the industry transitions to full DOCSIS 4.0.
When will DOCSIS 4.0 modems be on Amazon?
Retail DOCSIS 4.0 modems are expected to become available from major brands in mid-to-late 2026. As of March 2026, no consumer DOCSIS 4.0 modems are listed on Amazon. We will update this page as soon as they become available. In the meantime, the DOCSIS 3.1 modems listed above are the best options for most cable internet subscribers.
