The Comcast Speed Test, technically called the Xfinity xFi Speed Test (more on that below), is a Comcast-provided internet speed test.
This test is a completely free, web-based tool that you can use to see how much available bandwidth to the internet you have right now.Ach5 / Colleen Tighe
In other words, using the Comcast Speed Test, you can get a general idea of how quickly you're able to download and upload information over the internet, which impacts how well movies and music stream, how fast files download, and even how smooth your regular internet browsing is.
How to Use the Comcast Speed Test Tool
Using the Comcast Speed Test tool is very easy:
Visit the Xfinity Speed Test website.
Select Start Test.
Wait while the three parts of the test complete.
Viewing the Speed Test Results
If you're planning on benchmarking your internet speed with the Comcast Speed Test, you'll have to screenshot the results on the page. Before you do, however, be sure to open the Show More drop down so you can also capture the results for Upload Speed, Latency, Protocol, and Host.The Meaning of Bit Rates (Kbps, Mbps & Gbps)
How the Comcast Speed Test Works
Like almost all internet speed tests, the Comcast Speed Test downloads and uploads a relatively small amount of test data and measures how long it takes to do so.
Some simple math involving the size of the data packages, as well as the time they took to download or upload, provides a speed in Mbps.
The Comcast Speed Test also tests network latency, in addition, to upload and download speeds.
This test connects to the closest of 28 Comcast-hosted, OOKLA-powered, test servers to perform the test of your internet speed and latency.
Xfinity Speed Test and Comcast Speed Test
The Comcast Speed Test is the Xfinity Speed Test. The Xfinity Speed Test is the Comcast Speed Test. They're one and the same.
Xfinity is the name given to most of Comcast's consumer services, one of which is Xfinity Internet. Comcast rebranded their Comcast services as Xfinity beginning in 2010.
Even though the name change is a number of years old now, the Xfinity Speed Test is still more often referred to as the Comcast Speed Test.
Can You Use the Test If You're Not a Comcast Customer?
Yes. The Comcast Speed Test is available for anyone to use to test their internet speed.
Keep in mind, however, that there may be an internet speed test tool from your internet service provider which, depending on why you're testing your bandwidth, may be a better option for you.
Is the Comcast Speed Test Accurate?
With so many variables that impact your Comcast Speed Test results, it's almost impossible to say it is 100 percent accurate. It's the same with other bandwidth testing sites as well—the uncertainty isn't a Comcast/Xfinity problem alone.
That said, considering the fact that you are probably a Comcast/Xfinity customer, and assuming that you're testing your bandwidth with the Comcast Speed Test tool to benchmark changes over time or to make a case about your slow connection, you can consider the test as accurate as needed.