Comcast/XFINITY Speed Test Review

A complete look at the Comcast Speed Test (XFINITY Speed Test)

The Comcast Speed Test, technically called the XFINITY 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.

Person on a bed using XFinity Speed Test on a laptop
Lifewire / 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:

  1. Visit the XFINITY Speed Test website.

  2. Select Start Test.

    A screenshot of the Xfinity Speed Test web page.
  3. Wait while the three parts of the test complete.

Viewing the 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/Show Less drop down so you can also capture the results for Upload Speed, Latency, Protocol, and Host.

A screenshot of where to see additional test results on Xfinity's Speed Test.

You'll need to have JavaScript enabled in whatever browser you're using to use the Comcast Speed Test. Most computers are ready to go when it comes to using JavaScript.

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 27 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% 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.