Fixer.io - Fixer provides a free, simple, and lightweight API for current and historical foreign exchange rates and currency conversion. The API tracks rates published daily by the European Central Bank.
FXChoice - FXChoice is an Electronic Communications Networks broker that offers Contract For Differences and Forex trading on the most popular platforms.
exchangeratesapi.io - Foreign exchange rates API with currency conversion.
EagleFX - EagleFX is an online forex and crypto broker that offers competitive spreads, fast execution, and 24/7 customer support.
Open Exchange Rates - Free, hourly-updated exchange rates - a simple, accurate, open-source JSON API. Free for personal use, a bargain for everybody else.
IC Markets - Trade currencies, stocks, commodities, futures, bonds, and digital assets safely and securely with power for better trades.