Frankfurter

Open Source

Free, open-source exchange rates API sourced from European Central Bank data.

Overview

Frankfurter is a free, open-source exchange rates API built on European Central Bank reference rates. It requires no API key and applies no rate limit on the public instance.

Endpoints cover the latest rates, a specific historical date, and time series. The service can be self-hosted. ECB reference rates publish once per working day, and are intended for display, conversion, and reporting rather than for settling trades.

Common use cases

Convert between currencies using ECB reference rates
Fetch a historical rate for a given date
Chart an exchange rate time series
Self-host a rates endpoint with no API key

Key Features

Free exchange rates with no API key required
Sourced from European Central Bank reference rates
Historical and time-series endpoints
Fully open source and self-hostable
No rate limits on the public instance
Simple, stable endpoint contract

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