Frankfurter

Frankfurter is an open-source currency exchange rate API that provides reliable financial data based on reference rates from institutional sources such as the European Central Bank. It is designed to be simple, transparent, and free to use, with no API key requirements or usage limits, making it particularly attractive for developers and small projects. The API offers endpoints for retrieving the latest exchange rates, historical data, and time-series data, enabling both basic conversions and more advanced financial analysis. It allows users to specify base currencies and filter results by selected currencies, making responses efficient and customizable. The system can be used directly from client-side applications or self-hosted for full control over data access. Its lightweight design and straightforward JSON responses make integration easy across web and mobile environments.