DOCSIS 3.0 vs. DOCSIS 3.1: What’s the Difference?

Learn the difference between these two technologies and understand what that means for your modem.

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Last Updated: Dec 7, 2023
Illustration of numerous coaxial cables splayed out in an arc
With so many cable internet standards out there, it can take time to choose the right one for you.
  • DOCSIS stands for “Data Over Cable Service Interface Specification” and is the interface standard that determines how your modem translates internet signals into internet service.
  • The main differences between DOCSIS 3.0 and DOCSIS 3.1 are the maximum speeds and pricing.
  • Choosing between DOCSIS 3.0 and DOCSIS 3.1 will depend on your home’s specific internet uses.

Cable internet is by far one of the most popular internet connection types on the market due to its fast internet speeds and vast coverage. However, as cable internet providers revolutionize their modem technology to keep pace with cable’s popularity, you might find yourself between standards. When it comes to a DOCSIS 3.0 or a DOCSIS 3.1 modem, for instance, you probably have some questions. In this guide, we’ll walk you through the concept of DOCSIS, explain the differences between DOCSIS 3.0 and DOCSIS 3.1, and help you choose which one is best for your home.

What Is DOCSIS?

DOCSIS, also known as Data Over Cable Service Interface Specification, is a standard for transferring data between your cable internet service provider (ISP), modem, and device. The purpose of DOCSIS was to allow cable TV companies to provide internet services to their customers. The first version of DOCSIS was released in March 1997 and has since then continued to improve the receiving and transmitting of internet data.

What Are the Differences Between DOCSIS 3.0 and DOCSIS 3.1?

Most cable ISPs today provide either DOCSIS 3.0 modems or DOCSIS 3.1 modems (though some are even offering DOCSIS 4.0 modems). The main difference that’s important for you to know is that each standard provides a certain set of download and upload speeds. DOCSIS 3.1 is much quicker than DOCSIS 3.0 because it utilizes a whole host of advanced technologies to increase bandwidth and decrease latency, but we won’t cover those technical aspects here.

That said, whether or not the increased speed you’ll get from DOCSIS 3.1 matters to you will depend on your internet speed necessities and household activities. Use the following chart to compare the improved speeds of DOCSIS 3.1 against DOCSIS 3.0:

Version Download speeds Upload speeds
DOCSIS 3.0 Up to 1 Gbps Up to 216 Mbps
DOCSIS 3.1 Up to 10 Gbps Up to 1 Gbps

What Are the Pros and Cons of DOCSIS 3.0 and DOCSIS 3.1 Modems?

When choosing which DOCSIS modem is suitable for your household, you’ll need to consider the pros and cons of each technology. DOCSIS 3.1 is newer, but that goes hand in hand with being more expensive. DOCSIS 3.0 is cheaper, but it isn’t as secure, and it has slower speeds. The following table puts these pros and cons head to head between DOCSIS 3.0 and DOCSIS 3.1:

DOCSIS 3.0 DOCSIS 3.1
Pros
  • Budget-friendly modems
  • More modem options
  • Basic security features
  • Faster speeds
  • More robust security features
  • Backward compatible with older DOCSIS technologies
Cons
  • Slower speeds than 3.1
  • Aging technology
  • More expensive

Which DOCSIS Modem Is Better for Your Home?

Picture of an Xfinity DOCSIS 3.0 modem
Author Vivian Nguyen’s DOCSIS 3.0 Modem from Xfinity

Every internet plan is different, so your modem should follow suit. For me, I subscribe to a sub-gigabit cable internet plan from Xfinity, so using the provided DOCSIS 3.0 modem makes the most sense for my home. What makes sense for your home will depend on your number of users, internet speed, internet activities, and overall budget. The following sections offer some scenarios for when DOCSIS 3.1 or DOCSIS 3.0 would be better for you.

When Should You Use a DOCSIS 3.0 Modem?

DOCSIS 3.0 modems are great if users are looking for an affordable cable modem and aren’t using gigabit internet. You should consider a DOCSIS 3.0 modem if you:

  • Casually use the internet (browsing the web, sending emails, etc.)
  • Only stream in Standard Definition (SD) or High Definition (HD) on one device
  • Own few devices in your home

When Should You Use a DOCSIS 3.1 Modem?

DOCSIS 3.1 modems may be worth the investment if you need a more powerful modem for your internet needs. You should consider a DOCSIS 3.1 modem if you:

  • Play online games, livestream, or engage in other bandwidth-heavy tasks
  • Stream on multiple devices at a time in 4K resolution
  • Use multiple smart devices in your home

Do You Need to Upgrade to a DOCSIS 3.1 Modem?

Image of a modern modem and router combo
With DOCSIS 4.0 on the horizon, some people might wait to upgrade to DOCSIS 3.1.

If you plan on using gigabit internet and don’t mind the cost, upgrading to a DOCSIS 3.1 modem will let you make the most of the bandwidth you pay for through a gigabit internet plan. DOCSIS 3.1 modems are also future-proof, since most cable internet providers are transitioning away from DOCSIS 3.0 modems entirely. That said, users who currently own a DOCSIS 3.0 modem and have no plans to use gigabit internet can likely get away with skipping the upgrade and saving some money.

Frequently Asked Questions About DOCSIS

Do I need a DOCSIS 3.1 cable modem for gigabit cable internet?

Although DOCSIS 3.0 modems can support download speeds up to 1 Gbps, a DOCSIS 3.1 modem will guarantee gigabit internet with little to no latency. Plus, you can access much faster upload speeds with a DOCSIS 3.1 modem, making your gigabit plan more valuable.

What if my cable internet is below gigabit speeds (i.e., less than 1 Gbps)?

If your cable internet plan features speeds lower than 1 Gbps, you can save some money by purchasing a DOCSIS 3.0 modem. However, if you plan on upgrading your plan in the future, you should consider a DOCSIS 3.1 modem to keep your home networking setup up to date.

How will I know that my DOCSIS modem is working as intended?

Running an internet speed test and comparing it to your advertised plan speed is the best way to know you’re getting the most out of your modem.

What is DOCSIS 4.0?

DOCSIS 4.0 is the most recently released version of DOCSIS that supports multi-gigabit internet speeds. Modems supporting DOCSIS 4.0 offer download speeds up to 10 Gbps and upload speeds up to 6 Gbps, significantly faster than DOCSIS 3.1 modems.