Why Is My Comcast Internet So Slow All of A Sudden?

Wondering why is my Comcast internet so slow all of a sudden? Well, there are several possibilities in which your internet would perform really slow.

Luckily there are many solutions that can be applied even if you’re not a techy person so there is nothing to worry about.

With a little luck, we will discover the problem and boost your internet speed.

If your internet got bad all of a sudden, we can exclude the possibility of you having a slow supplier plan from the list of possible causes. The very first step in cases like this would be to restart your router/modem. Next, ensure that your WiFi is performing well by connecting to it from another device. 

Lastly, you can test your network speed online for free and find out if the issue is coming from Xfinity or you.

Even if you still cannot find where the problem is coming from, next we will take a closer look at all possible causes.

Why Is Comcast Not Getting Full Speed?

If one thing is worse than a slow internet it would be not knowing why. Xfinity is known to be a fast internet provider and if you are experiencing issues then the issue is most likely on your side.

Below are listed most of the possible causes so we recommend taking a look so you can troubleshoot the issue easier afterward:

• Slow data plan.
• Router/Modem Issue.
• Bad WiFi.
• Xfinity maintenance.
• Overloaded network.
• Hardware damage.

These are the most frequent scenarios in which Comcast’s internet will perform slower than its intended speed.

Unfortunately, we still don’t know whether the issue is coming from Xfinity or from your side. Let’s find out!

Is The Issue from Them Or From Me?

To diagnose we are going to take several things into consideration. To ease it up for you, we’ve prepared a number of symptoms, which mean that the issue is coming from Xfinity and not you.

1. WiFi is good but sudden loss or slow internet connection.
2. Less data than your plan provides.
3. Slow internet even with a wired connection.
4. Slow internet on a specific device.
5. First time experiencing this issue.

If you are experiencing more than 1 of the above-listed symptoms you should call Xfinity right away.

You can also reach them via email, and hopefully, the issue would be on their side. If not let’s jump right into the solutions.

How To Fix Comcast Xfinity Slow Internet?

With the help of other forum members with the same issue as yours, we have prepared a handful of methods for you to apply and hopefully fix your Comcast Internet.

We recommend applying our methods in numerical order for the best results.

Method #1 Restart

It is always best to start with a restart of all devices included in the workflow.

To take the troubleshooting one step further you can perform the so-called “Power Cycle” which will discharge your devices and hopefully resolve any temporal issues and glitches.

We recommend performing a power cycle on both your router and the device you’re connecting to your Comcast internet. Here is how to do it properly:

1. Turn off the device by pressing the power button.
2. Plug out the device from the power outlet.
3. Wait for about 3-5 minutes.
4. Plug the device back into the wall outlet.
5. Power on the device and wait for all services to get online.

Tip: Avoid using power strippers or devices to exclude the possibility of a power failure throughout your device workflow.

Method #2 Check WiFi

If your Comcast not getting full speed, the reason could be located in a bad WiFi.

To put this theory to the test, feel free to connect to that particular WiFi, using another device, and surf the web.

Watch some videos online to determine if the issue is throughout all of your devices or not. If the internet is slow on all devices you might have faulty WiFi or the connection to it is compromised.

In that case, you have two options:

• Connect your device using a wired connection (Ethernet cable).
• Move your router closer to the device you’re connecting with.

To find out if your WiFi connection is slow you can use a free internet speed online or move closer to your router.

If the connection improves then you should close the distance between router and device.

Note: If you are using a 5GHz network you should be aware that it has a hard time traveling through more than one wall. 

As far as the 2.4Ghz network, it is proven to work better when it comes down to travel through solid objects.

Method #3 Relieve Network & Disable Drainers

Still, wondering why is Comcast’s internet not getting full speed? Then try disabling any consumer software or downloading processes that might be compromising your internet speed.

Check if there is a download in process and cancel it

Considering that your network speed goes slow all of a sudden, you can’t exclude the possibility of your internet getting overwhelmed.

Try disconnecting all devices from your network and possibly disabling any VPN software that is actively running.

To disconnect your devices simply turn their WiFi functionality off. Once you relieve your network from all connected devices run a speed test to find out if it has gotten better.

Method #4 Update Your Router Firmware

In this method, we are going to address your router/modem again.

It is well-known that your Comcast internet would be slow if you have outdated modem firmware. You can process the update (if available) from the router’s control panel.

Here is how to reach your modem’s control panel:

Note: Steps are designed for Windows OS devices:

• Open your CMD as administrator.
• Type “/ipconfig” and hit Enter.
• A list of IP addresses will appear.
• Copy the IPv4 address.
• Open a browser (preferably Google Chrome) and paste the copied IP address.
• Login to your router control panel by inserting the credentials (admin/admin). If “admin/admin does not work, call your supplier for assistance.
• Locate the update tab and update the firmware.

Tip: To discover your IP, you can also search in Google “What’s my IP?” and copy it from there.

If updating your router does not help or there is no room for updating, in our last method we’re going to reset your router to default settings so pay close attention.

Method #5 Reset Router

As a last resort, you will learn how to perform a factory reset on your router and hopefully resolve your problem.

Note that a factory reset will erase all data from your router. All personal configuration and settings (including WiFi) will be permanently lost.

Here is how to perform a factory reset:

• Locate the little pin-hole on the back panel of your router.
• Reach inside using a sharp object like a needle or pencil.
• Press the reset button within the pin-hole and hold until lights fade out.
• Wait for a few minutes for the router to reset.

Once ready use method 4 to reach inside the control panel and configure your WiFi. Then connect your device to the network and test it.

Tip: If admin/admin did not work on your previous try, after the reset you should be able to log in this way.

Read Next: How to Replace Comcast Modem?

Bottom Line:

We hope that now you know why is my Comcast internet so slow all of a sudden and most importantly how to resolve the problem fast and easy.

If you were not able to improve the speed of your Comcast internet, as a last resort you can contact Xfinity for additional assistance or find out if there is maintenance on their side.

For more relevant posts feel free to check our tech blog, in which you will definitely find a solution to all your smart home issues.