Shorten.REST - A URL shortener API you can depend on
Rebrandly - Rebrandly is the easiest way to create, share and manage branded links.
Pixela - Record and Track your habits or effort. All by API.
PixelMe - URL shortener for savvy marketers
chl.li URL shortener - A simple, modern, free and privacy-friendly URL shortener.
Cutt.ly - Free custom URL Shortener and branded URLs with advanced links tracking and Link Management Platform & API.