Checking your Comcast upload speed is as simple as going to Comcast’s site and clicking on a link. As easy as this sounds, several other factors come into play when you’re trying to determine an accurate upload speed (remember: check your bandwidth performance regularly with an Internet speed test). Software, hardware, and network setups can all be culprits in giving a false reading.



Programs such antivirus tools and firewalls will slow down data package exchanges, which in turn will slow down upload speeds. You could disable these programs to get a truer rating, but this is not recommended, as disabling these programs would make your computer vulnerable to viruses.


Any wireless devices should be hardwired to the device you are testing. Wireless devices slow down upload speeds because of the added latency from sending data across open radio waves.

Remove excess devices in the network. Connecting to the modem, then to the router, then to a personal server machine, and then to the computer can add more latency issues, causing an incorrect reading. The more devices the signal has to pass through, the slower the reading will be.

Testing the Upload Speed

To test the Comcast upload speed of your device, do the following:

  • Go to the Comcast Speed Test site.
  • Click the server on the map closest to your location.

The tool will first test your overall latency. The smaller the number, the less interference you are having with the connection. Then the tool will test the device’s download speed. Lastly, the speed test will check and display your upload speed.

The real question here is what is the upload speed? When testing your Comcast upload speed, you may get a lower value than you expected. In other words, the speed in which you upload data will almost always be lower than what your network’s capabilities are. So, when deciding the data speed you require, don’t look at the numbers Comcast gives you. Instead, connect your specific device to the network and run the speed test. Then decide if you need faster speeds or if a slower speed will work fine.