Whaa.tk is not available for Windows but there are a few alternatives that runs on Windows with similar functionality. The best open source Windows alternative is Polr. If that doesn't suit you, our users have ranked more than 50 alternatives to Whaa.tk and three of them are open source and available for Windows so hopefully you can find a suitable replacement. Other interesting open source Windows alternatives to Whaa.tk are UrlHum and Pygmy.
Like everything else here, Polr is an open source and self-hostable web application. It's a fast and simple URL shortener with a robust API for using with command line applications.
UrlHum provides advanced analytics data without ruining users experience and keeping their Privacy safe.
