DOCSIS 3.1 is built for speed and security, but the 3.0 models are cheaper and still plenty capable.
David AndersSenior Writer
David Anders is a senior writer for CNET covering broadband providers, smart home devices and security products. Prior to joining CNET, David built his industry expertise writing for the broadband marketplace Allconnect. In his 5 plus years covering broadband, David's work has been referenced by a variety of sources including ArcGIS, DIRECTV and more. David is from and currently resides in the Charlotte area with his wife, son and two cats.
ExpertiseBroadband providers, Home internet, Security Cameras
When you sign up for internet, you typically choose an internet speed. That speed, or close too it, is what your provider claims to send to your home. From there, the equipment you have plays the biggest role in the actual speeds you get inside your home. If you have cable internet, a key component of that equipment is a DOCSIS 3.0 or 3.1 modem.
DOCSIS stands for "data over cable service interface specifications," the key there being "data over cable service." It's the interface standard that determines how a modem receives internet signals from a cable ISP and translates them into the internet service you use to surf the web and stream TV shows.
It also sets the standard for how your input -- like entering "cheap internet" in a search engine -- is translated into data the internet outside your home can understand. Your cable modem is at the center of all those actions, and it's all but guaranteed to be a DOCSIS 3.0 or 3.1 device.
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What's the difference between DOCSIS 3.0 and DOCSIS 3.1?
Despite the simple one-tenth difference in versions, there are significant differences between DOCSIS 3.0 and 3.1, including performance, pricing and availability. Let's take a look at what those are to help you determine which type of device, DOCSIS 3.0 or DOCSIS 3.1, is best for your home.
DOCSIS 3.0 modem advantages
Price: DOCSIS 3.0 cable modems are generally cheaper than their 3.1 counterparts.
Availability: You're likely to have more options, including used or refurbished devices, when shopping for a DOCSIS 3.0 modem.
DOCSIS 3.1 modem advantages
Speed: DOCSIS 3.1 cable modems support faster speeds than DOCSIS 3.0 modems, and are thus better suited for high speed plans, especially those with gig speeds or higher.
Security: While both modems have built-in security features, DOCSIS 3.1 modems are likely to offer the best online security, especially if you purchase a modem-router combo device.
Long-term use: DOCSIS 3.0 modems aren't exactly outdated yet, but it's safe to say 3.1 modems are the best option for long-term use.
DOCSIS 3.1 supports faster speeds, if you need that
Max download speed
Max upload speed
The most significant difference between DOCSIS 3.0 and 3.1 is that the latter can support download speeds 10 times faster than DOCSIS 3.0, up to 10Gbps. That's impressive, but unless you've got a particularly high-speed plan, that probably won't matter.
Locating local internet providers
Most cable providers do offer a gigabit plan with max speeds around 940 or 1,000Mbps. Still, as of this writing, Astound and Xfinity are the only major cable internet providers that offer a plan with faster max speeds (1,200Mbps in select areas).
If you rent equipment through Astound or Xfinity, you'll receive a modem-router combo that comes with DOCSIS 3.1 built in, so you don't have to worry about it. Otherwise, if you choose to use your own equipment, you'll want to spend a little extra for a DOCSIS 3.1 modem to take full advantage of the plan's speed potential.
DOCSIS 3.1 is definitely the way to go on plans faster than 1Gbps, but even if your plan comes with 1,000Mbps, 940Mbps or lower, say in the 400 to 600Mbps range, a DOCSIS 3.1 modem may be the better choice for performance.
Speeds up to 1Gbps are the max a DOCSIS 3.0 modem can handle, so you're likely to get more consistent performance from a 3.1 device that is equipped for faster speeds. Major cable internet providers including Cox, Optimum and Spectrum also offer a DOCSIS 3.1 modem with mid- and higher-tiered internet plans, including gigabit service.
But suppose your plan comes with speeds up to 200Mbps. If you rent from the provider, the modem included with your equipment will likely be a DOCSIS 3.0 model, which is more than capable of supporting your internet connection.
If opting to use your own modem, you probably won't see much of a performance improvement, if any, by choosing a DOCSIS 3.1 device over a DOCSIS 3.0 one. And considering the price difference and available options between the two, you'd be better off opting for DOCSIS 3.0 on that lower-tiered internet plan.
DOCSIS 3.0 has more, cheaper options
DOCSIS 3.0 is likely to present cheaper options when shopping for a modem or modem-router combo. New DOCSIS 3.0 modems can cost between $50 and $150 depending on the device you choose and the source you buy from, but you may be able to score a used device for less than $50. On the other hand, DOCSIS 3.1 modems can easily cost $150-$250 or higher. And, since the technology is relatively new, at least in use, finding a cheaper, used device may be more of a challenge.
Meanwhile, manufacturers like Arris, Asus, Netgear and Motorola have made DOCSIS 3.0 modems for years. These manufacturers make DOCSIS 3.1 modems as well, but you'll have fewer options than you would if you were shopping for a DOCSIS 3.0 modem, at least for now.
But DOCSIS 3.1 is more secure...
Any major internet protocol update, like the transition from DOCSIS 3.0 to 3.1, will include improved security features, typically in the form of enhanced encryption, so it's safe to say DOCSIS 3.1 will do a better job of keeping you safe online. Additionally, the best router and modem combos that are equipped with DOCSIS 3.1 will also include WPA3, a more advanced router security feature than older modem-routers that may come with DOCSIS 3.0 and WPA2.
To be clear, DOCSIS 3.0 came out in 2006 and DOCSIS 3.1 arrived in 2013, which is quite a long time in the tech world -- long enough for initial security measures to become outdated. Modem manufacturers and ISPs release regular security updates to keep your equipment safe. However, you still may want to consider additional security software or using a good VPN to help boost your online security.
...and essentially future-proof
The need for DOCSIS 3.1 modems has risen in recent years as home internet speeds have drastically improved. According to the Federal Communications Commission, only around 6% of US households had access to internet speeds of 1,000Mbps or higher in June 2016, compared to more than 33% in December 2022.
Though fiber internet, not necessarily cable, is the main contributor to that jump, it's still an indicator that home internet speeds are going up. For example, in the same time frame, Xfinity speeds of 500Mbps or higher were available in less than 3% of service areas, whereas those speeds are now available in 99% of its service areas.
All of this is to say that DOCSIS 3.1 is well on its way to replacing DOCSIS 3.0. It hasn't entirely done so just yet, mainly because slower, cheaper cable internet plans can still get by with DOCSIS 3.0 technology. Still, as faster plans become more available and affordable, DOCSIS 3.1 will emerge as the go-to standard for cable modems. We're just not there yet.
So why choose one over the other?
If you're content with a low to midtier cable internet plan, then a DOCSIS 3.0 modem will likely meet all your needs and come at a lower price tag than a DOCSIS 3.1 device. But if you want faster speeds, especially those approaching or surpassing 1Gbps, or simply want a device you know you can use for years to come, a DOCSIS 3.1 modem is the way to go. You'll have to pay more for a DOCSIS 3.1 modem, but chances are you're also paying a premium for those faster speeds, so you might as well equip your home with a device that will let you enjoy them.