speedtest-cli is not available for Windows but there are some alternatives that runs on Windows with similar functionality. The best Windows alternative is Speedtest by Ookla, which is free. If that doesn't suit you, our users have ranked more than 25 alternatives to speedtest-cli and six of them are available for Windows so hopefully you can find a suitable replacement. Other interesting Windows alternatives to speedtest-cli are Speed Test Loggger (Free, Open Source), Network Speed Test (Free), Speedtest (Go) (Free) and MyConnection PC (Free Personal).
Network Speed Test can provide you detailed information about the upload and download speeds of your internet connections. The App also maintains a history of the internet connections you’ve tested for easy comparison.
MyConnection PC tests your Internet connection to Visualware server locations, and provides an analysis of your download and upload speeds, connection quality, supported VoIP call quality, along with key information to identify and resolve connection problems.