Exchange rates API is a free service for current and historical foreign exchange rates published by the European Central Bank.
Fully Fixer.io compatible with JSON & CORS support'. There are six alternatives to exchangeratesapi.io for Online / Web-based, Self-Hosted solutions and SaaS. The best alternative is Fixer.io, which is both free and Open Source. Other great apps like exchangeratesapi.io are xChangeApi (Freemium), ExchangeRate-API (Freemium), BankExchange (Freemium) and Nozomi (Freemium).