Fixer.io
Fixer.io is a free, open-source foreign exchange rates and currency conversion JSON API. It returns current as well as historical data and is updated daily.
ExchangeRate-API
A reliable, easy to use and fast Exchange Rate API. Currency conversion can be implemented in any language in a few lines of c ...
exchangeratesapi.io
Foreign exchange rates API with currency conversion. Exchange rates API is a free service for current and historical foreign e ...
BankExchange
API for historical exchange rates from 53 central banks from around the world with a single integration point
Open Exchange Rates
Free, hourly-updated exchange rates and currency data - a simple, accurate, easy-to-integrate JSON API with great documentatio ...