Bandwidth Place
Bandwidth Place

June 15, 2021

Running a bandwidth speed test provides answers to many questions about your Internet connection. Looking to find out how quickly you can download and upload files to the Web? What if you’re not getting the fastest possible service from your provider? Whatever it is, an Internet speed test usually offers the insights you need.

Comcast Xfinity is the largest internet service provider (ISP) in America. Famous for it’s high-quality signals, extensive coverage across the nation, fast reliable speeds, and trusted service. It’s no wonder why Xfinity is proud to be America’s best Internet experience. 

Now, when talking about high speed internet on an individual consumer basis, no two connections are the same. Meaning select areas might get lightning-fast Xfinity speed, while others may struggle with spotty connections. No ISP can claim to provide flawless home internet. For some, that means facing the reality of broken, or slow, internet. 

The Xfinity speed test tool checks your internet speed by calculating the time taken for each byte to travel from a remote server to your web-enabled device. Note that these speed test results are often lower than your plan speed due to a number of factors outside of your ISP’s control.

Using this guide, we’ll walk you through how to run an Xfinity speed test, help you understand your results, and answer any questions you may have about your internet speed and web connection.

What is an Internet Speed Test?

An Internet speed test measures the broadband connection limits of your Internet. This process is completed by sending a small file from the server. The test then analyzes the time it takes to send and receive data back to the server.

Internet speed tests measure a number of important items, including:

  • Upload and Download speeds
  • Data Caps
  • Bandwidth
  • and Latency Ping

Note that some Internet speed tests do not report all of these items, but speed and bandwidth are pretty standard across all tests.

How to run an Xfinity Internet Speed Test:

Step 1: Optimize your test

Before you run the test, it might help to:

  • Disable any software that can slow down the test
  • Disconnect any hardware that can cause high latency

Step 2: Access the Comcast Speed Test

Simply select “Start Test,” when prompted. 

The test should take no longer than 30 seconds. The page will automatically refresh with your results when done.

Step 3: Survey your results

Your speed test results will present a checklist of five items:

  1. Send/receive email
  2. Browse the Internet
  3. Stream HD video
  4. Stream 4K video
  5. Speedy downloads

A green checkmark next to any of the listed items means you have suitable internet connection. A red “X” means your connection is too slow. Now you have a better gauge of how your internet is (or is not) working.

For a more in depth look, select “Show More” on that same page to reveal your upload speed, latency, protocol, and host. Check out the glossary of speed test terms below if you need further clarification or help.

Xfinity Internet speed test terms

What is Upload Speed?

Upload speed is the rate at which data is transferred from your device to the Internet. It effectively measures how many megabits of data per second you can send from one device to another device or server on the Internet. Common online activities, like sending emails, video-chatting, and tournament-style games, require fast upload rates. Upload speed is measured in megabits per second (Mbps).

What is Download Speed?

Similar to upload speed, download speed measures the time it takes for data to be transferred from the Internet to your device. Most bandwidth connections are designed to deliver faster download speeds than upload speeds as the vast majority of online activity (streaming videos, loading webpages, online gaming, or even someone who works from home, etc.) are dependent upon fast download speeds.

What is Ping?

Ping measures the reaction time of your connection, reporting how fast you’re able to get a response after you’ve sent out a request. The faster your ping, the more responsive your connection. This is vital for applications and programs where timing is crucial. Ping is measured in milliseconds (ms).

What is Mbps?

Megabits Per Second. This unit of measurement surveys the bandwidth capacity of an Internet connection, telling you how much data you are able to transfer each second.

What is Bandwidth?

Bandwidth identifies the maximum amount of data able to be transmitted via an Internet connection within a specified amount of time. Though often mistaken for Internet speed, bandwidth refers to the volume of information that can be sent rather than the rate in which it’s sent. Bandwidth is measured in megabits per second (Mbps).

What is Latency?

Though similar to ping, latency is the measure of time between a request and a result. Latency tells you how much time it takes for a signal to travel to your ISP’s server and back. Lower latency means shorter lag time, so the more you can reduce latency, the better. Latency is measured in milliseconds (ms).

Why is my Xfinity Internet Speed So Slow?

Take a look at these five common issues that may be holding you back from a speedy web connection.

Your WiFi signal is bad

A weak, or spotty WiFi signal is usually the reason why your Internet speed struggles. Jarring slowdowns, long download times, and frequent disconnections are all tell-tale signs of a bad WiFi router. While resetting your router might solve many basic issues, hardware problems could require you to replace your router to get your connection up to speed.

Network latency is too high

Internet performance relies mostly on two essential elements: bandwidth and latency. As mentioned earlier, when latency is too high, your performance quality plummets. From network throttling to congestion, there are a number of factors out of your control that can affect your Xfinity network latency.

You’re on a low-tier Internet plan

Like any ISP, Comcast Xfinity offers a number of service plans that work on a tiered system—the more premiere the plan, the faster the speed.

If you’re unsure of what Internet speeds your Xfinity plan promises, log in to your Xfinity account and access your plan details. There you’ll be able to see what speeds you are paying for, versus the speeds your wireless network is actually getting. In the event that your Xfinity speed test results don’t match up with what your plan offers, reach out to Xfinity Support to speak with a representative who can help solve any issues.

Your device may have a virus

If your computer has fallen prey to malware or a virus, your web connection will likely suffer. Note, these malicious bugs fester on your computer and curb your Internet speeds. Spyware, in particular, monopolizes your Internet connection and causes delays, and can ruin your PC performance altogether.

Running your system through an antivirus check can help you determine whether or not a digital infection is the cause of your slow speeds.

Your computer is too slow

Poor PC performance can often result in poor internet connection, too. If you’re dealing with an older system, poor trip time, or even everyday struggles to accommodate your input, your PC may be the problem, not your Internet connection. To check if this is the case, run an Xfinity Internet speed test on a different device. Note that if the results are significantly faster than that of your PC test, assume that your computer is the problem.

Freeing up hard drive space, clearing your cache, deleting files, and emptying your digital trash can are all easy ways to speed up your computer and make more room for speedy connectivity.

What factors alter Xfinity speed test results?

In order to obtain accurate speed test results, you must first ensure your environment is ideal for the test. However, there are a number of factors–both software and hardware–that can alter your speed test results:


Certain types of software programs installed on your computer can cause major slowdowns. If you’re running too many apps that require a web-connection to function, performance will likely take a hit. Some software programs also run in the background without you knowing, slowing you down all the while. Not only can software affect your real-time connection quality, but it can also affect your Xfinity speed check results.

Firewalls, antivirus programs, and administration tools are common PC software programs that can also slow down your speeds. These programs effectively monitor each and every piece of data sent to the computer. In some cases, they supply extra data to help with encryption. Before running an Xfinity speed test, be sure to disable all of these programs.

Your browser of choice (Chrome, Safari, Edge, Firefox, etc.) may also yield different results.  Each browser varies in performance, which is why you may see different results from a test conducted in Chrome vs Safari. Though there is no solid answer as to which browser is best, it’s wise to run your speed test on your most preferred browser to get an accurate reading of your regular speeds.


All types of web-connected devices produce different speed test results even when using the same exact ISP. Expect different results on a tablet or smartphone, compared to a desktop computer. These are due to available bandwidth, internal hardware, connection type, and even network cables.

Your internet speed heavily depends on the availability and quality of certain network equipment. In most cases, the router or modem is responsible for connecting you to the web.

If you wirelessly connect via WiFi to your router, expect slower results than a wired ethernet cable. Ultimately, stability plays a significant role in determining your internet’s performance.

Also, the number of users on a single household connection could affect your broadband speeds. This is also true of your larger ISP network connection. If you happen to conduct an Xfinity Internet speed test during work hours while most people are active online, the results are likely going to be less impressive than the results you’d get during a test beyond peak hours.

What is considered Fast Internet speed?

The FCC stated that fast Internet is a connection offering download speeds of at least 25 Mbps and upload speeds of at least 3 Mbps. These speeds seamlessly support most common online activities, including HD video streaming, online gaming, and music downloading.

Download speeds of at least 25 Mbps (typical of cable internet) easily accommodates the average household’s needs. However, a larger household may need extra bandwidth for more intense online demands, and therefore might require a faster tier.

What is considered slow Internet speed?

Based on FCC evaluations, download speeds below 25 Mbps are too slow to be considered broadband.  Expect frequent video-buffering, difficulty connecting multiple web-enabled devices, and a slew of other frustrating connectivity issues.

It’s important to note that DSL is the most common type of internet that offers speeds below the standard 25 Mbps. Though it may not be as popular as it used to be, it still provides a sound solution for those looking for a reliable connection for basic online activities. 

How can I make my Xfinity Internet faster?

Before contacting Xfinity Support, check to see if you’re currently downloading something. A bandwidth-hogging program might also be slowing down your connection. Then try our suggested hardware and software modification tips, and run as many speed tests as you need.

If your Xfinity speed test results still seem too slow for your liking, try rebooting your device(s), modem(s), and router(s). This can often fix any slowdowns you might have encountered.

If you still encounter problems, contact Xfinity Support for help. A service representative should be able to help you solve most issues. It could be time to upgrade tiers? Check out our pricing page to see if there’s a plan that’s right for you. 

Bandwidth Place
Bandwidth Place