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CNET dug into the latest speed test data to see how the country’s largest cable internet provider fared in national speed test data.

Your internet connection is more important than ever. Whether you’re working remotely, taking online classes, streaming your favorite shows or running a smart home, your internet service provider plays a key role in keeping everything running smoothly. In fact, it’s become as essential as your other utilities like gas, water and electricity.

One of the simplest ways to ensure you’re getting the service you’re paying for is to run a speed test. It gives you a quick look at the download and upload speeds your provider is delivering in megabits per second.

Several reliable speed tests are available online. However, this page focuses on results from Speedtest.net, a widely used platform created by Ookla. (Ookla is owned by the same parent company as CNET, Ziff Davis.) Those reports are based on millions of tests run by internet users across the country.

Where did Xfinity place among the top US internet providers?

For the most recent data (July to December 2024), Xfinity found itself in third place — behind AT&T Fiber and Verizon Fios — among the country’s biggest ISPs. It had a Speed Score (which Ookla defines as a combination of download and upload performance) of just over 251.

Fastest fixed internet providers in the US

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 six-month period. For example, Ziply Fiber, a provider that services the Northwest, boasts the country’s fastest residential internet plan at 50 gigabits per second. But because it’s only available in that portion of the country, it won’t show up on the national list (although it certainly registered as the fastest provider in the state of Washington).

Also of note is that the 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 5G 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 nearly 7 million subscribers, was not quite large enough for it to crack into consideration on the top list.

Does every Xfinity customer get 251Mbps?

Although Xfinity speed test results with Ookla garnered a Speed Score of 251, that doesn’t equate to every Xfinity subscriber getting at least 251Mbps. However, it does show that most Xfinity customers will have a consistent internet experience. Ookla has a “Consistency” ranking — which shows the percentage of results registered above broadband speed (based on the FCC’s old 25Mbps download and 3Mbps upload, not the more recent designation of 100/20) — and Xfinity landed in third place, with a 92.4% rating.

That can also be combined with the FCC’s findings that more than 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 or four speed tiers but Xfinity is unique because it boasts sixn internet speed options. That’s quite a bit more choice for customers than one usually encounters.

Xfinity speed tiers

Source: CNET analysis of provider data.

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.

US states where Xfinity was the top ISP

Comcast’s Xfinity internet service is available in 39 states, giving it a decent chance at grabbing the top spot in several areas. It grabbed the crown for five regions, second only to AT&T Fiber at 18.

• Arizona — 243Mbps
• Colorado — 245Mbps
• District of Columbia — 215Mbps
• New Hampshire — 256Mbps
• Oregon — 232Mbps

US cities where Xfinity was the top ISP

The Ookla data only considers the country’s top 100 most populous cities for city speeds. On that list, Xfinity was the fastest provider in eight towns, second again only to AT&T Fiber, which grabbed the top spot in 17 US cities.

• Albuquerque, New Mexico — 235Mbps
• Aurora, Colorado — 290Mbps
• Baltimore, Maryland — 227Mbps
• Denver, Colorado — 188Mbps
• Portland, Oregon — 243Mbps
• St. Paul, Minnesota — 243Mbps
• Tucson, Arizona — 226Mbps
• Washington, DC — 215Mbps

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 almost every way. That’s undoubtedly true. But most fiber ISPs with a large national footprint — AT&T, Frontier, Optimum and Verizon — don’t offer fiber internet plans exclusively. Their coverage areas 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