pth.bz provides a simple JSON API to shorten links, create interstitial redirect pages, and generate high-res PNG QR codes. Make permanent 301 or JS interstitial links via POST /api/shorten {url}, then access QR codes via /?qr=CODE or /?qi=CODE with &px=200–2048 for sizing. Supports CORS, no auth needed. Limits: 30 reqs per 10 mins per IP, URL <=2000 chars.
Free URL Shortener offers a powerful API to interact with other sites
Shorten long URLs
Short URLs support so many domains
Generate or get existing short URLs, with sequential or custom keyword.
Custom URL shortener for sharing branded links