Our internet connections have increasingly become the lifeblood of our households. Whether you're working from home, taking extra online courses, streaming your favorite TV shows or updating your place with all the best smart home devices, your internet service provider is almost as important as your gas, water and electricity suppliers. What's one of the best ways to ensure your ISP delivers on its promises? Run a speed test.

A speed test will give you a snapshot of the megabits-per-second download and upload speeds you're getting from your provider. There are several good internet speed tests out there. If you're a Comcast Xfinity customer, in particular, Xfinity boasts its own speed test, available at Speedtest.Xfinity.com. But as I delve more specifically into Xfinity speed test results, this page will largely reflect data from Speedtest.net. It's the tool from Ookla, which quarterly publishes the results gathered from millions of customer uses of its speed test. 

Where did Xfinity place among the top US internet providers?

For the third quarter of 2023, Xfinity found itself in third place, behind Cox and Spectrum, among the country's biggest ISPs. It finished just ahead of AT&T, notching a median download speed of 236 megabits per second.

In order to qualify as one of the country's top internet providers, an ISP must appear in 3% or more of the total test data taken during the three-month period. For example, EPB, a provider in Chattanooga, Tennessee, boasts the country's fastest residential internet plan at 25 gigabits per second. But since it's only available in that portion of the country, it won't show up on the national list (though it certainly registered in the state of Tennessee).

Also of note, that 3% threshold is based on the data taken from tests run by customers across the country, not simply whether a provider covers 3% of the country. T-Mobile Home Internet, for example, is now available to 70% of the country, according to the Federal Communications Commission's National Broadband Map. However, its customer base, which has grown to over 3 million subscribers, was not quite large enough for it to crack into consideration on that top list.

Does every Xfinity customer get 236Mbps?

Though Xfinity speed test results with Ookla garnered a median download speed rating of 236Mbps, that doesn't equate to every Xfinity subscriber getting at least 236Mbps. However, it does show that most Xfinity customers will have a consistent internet experience. In fact, Ookla has a "Consistency" ranking -- which shows the percentage of results registered above broadband speed (25Mbps download and 3Mbps upload) -- and Xfinity landed near the top of that chart, with a 91.6% rating.

That can also be combined with the FCC's recent findings that over 90% of participants experienced actual median download speeds of at least 95% of the ISP's advertised download speed. That's certainly another good way to determine consistency for the customer. But what are the advertised speeds offered by Xfinity?

Available Xfinity internet speeds

Most ISPs offer three to five different speed tiers, but Xfinity is unique in that it boasts seven to eight different internet speed options, depending on your location. That's quite a bit more choice for customers than one normally encounters.

Brian L. Roberts, chairman and CEO of Comcast, said during a January earnings call that Gigabit Plus customers comprise roughly one-third of Xfinity broadband subscribers. That's consistent with OpenVault's latest data for internet customers across the US, which has gigabit (and above) consumption at approximately 32%. Overall, according to OpenVault, most customers (36%) opt for a plan of 200 to 400Mbps. The rest of the data shows 16% go with 100 to 200Mbps, 5% are in the 50-to-100Mbps category, 6% choose 500 to 900Mbps and 5% are on plans under 50Mbps.

For Xfinity, all plans are a hybrid fiber-coaxial cable connection, so customers' download speeds will be much faster than their upload speeds. The one exception is the Gigabit Pro plan, which is a 100% fiber connection. While it's theoretically available throughout Xfinity's national footprint, FCC numbers indicate it's only available to approximately 4% of Xfinity's customer base.

Comcast's Xfinity internet service is available in 39 states and Washington, DC, giving it a decent chance at grabbing the top spot in several states. It had the slowest showing in Massachusetts at 217Mbps and its fastest download speed at 255Mbps in Colorado.

As for city speeds, the Ookla data only considers the country's top 100 most populous cities. On that list, Xfinity was the fastest provider in 15 cities, which put it in second place to AT&T, which grabbed the top spot in 18 US cities. Memphis, Tennessee, brought up the rear for Xfinity, with a median download speed of 193Mbps. Xfinity scored its fastest median download speed in Colorado Springs, Colorado, with 275Mbps.

Final thoughts on Xfinity's speed test results

If you've read any of CNET's home internet coverage, you've heard us say that fiber internet trumps cable internet in just about every way. That's certainly true. But most fiber ISPs with a large national footprint -- AT&T, Frontier, Optimum and Verizon -- don't exclusively offer fiber internet plans. Their coverage areas also include a mix of slower connection types like digital subscriber line. The speed test results in those areas will be significantly lower than the fiber numbers, thus making the providers' total numbers lower. But Xfinity, and other cable internet providers that don't have to deal with DSL dragging down their numbers, will see a much more consistent performance across the country. In that way, cable trumps the fiber-DSL combo.

Xfinity speed test FAQs