We've analyzed and compared the top 1 API providers supporting Latest rates for Nigerian developers and businesses. Find the right infrastructure fit for your startup below.
Written by Editorial Staffs as at 22nd June, 2026
| Feature | |
|---|---|
| Pricing | Completely free; no API key required; open source |
| Latest rates | Yes |
| Historical rates | Yes |
| Currency conversion | Yes |
| Time series data | Yes |
| Base currency switching | Yes |
| View Details |
Frankfurter is a free, open-source currency exchange rates API built on top of official European Central Bank reference exchange rate data. The project delivers ECB foreign exchange rates through a clean, modern REST API with no registration requirement, no API key, and no rate limits documented — offering a completely frictionless entry point for developers who need reliable currency conversion data powered by one of the world most authoritative central bank rate sources. The European Central Bank publishes official reference exchange rates for 32 currencies against the Euro on each business day at approximately 16:00 CET. These reference rates are computed from the aggregate of market rates reported by financial institutions across the eurozone, making them the official benchmark for euro currency conversions in European financial reporting and compliance contexts. Frankfurter exposes these ECB rates through a straightforward REST API that makes accessing them as simple as an HTTP GET request. The latest rates endpoint returns the most recently published ECB exchange rate set for all supported currencies relative to any specified base currency. By default, rates are base EUR, but any supported currency can be used as the base by specifying it in the request parameter. This flexibility allows applications to retrieve NGN/USD, EUR/GBP, or any other combination without client-side conversion math. The response is a clean JSON object with ISO 4217 currency codes as keys and decimal rate values. Historical rates are accessible for any date from January 4, 1999, when the ECB began publishing its reference rates, through the present. This exceptional historical depth of over 25 years of official ECB rates supports the most demanding historical analysis use cases. Nigerian financial researchers studying the long-term trajectory of major currencies, academics modeling currency relationships, or developers building historical FX analysis tools for Nigerian businesses with international exposure can query any specific date or date range within this extensive archive. Time series queries retrieve exchange rates across a date range in a single request, returning a day-by-day array of rate sets between the start and end dates. This is more efficient than making individual date queries for each day in a range and enables building currency trend charts, calculating moving averages, or analyzing rate volatility across specific periods of interest. A currency conversion endpoint simplifies the most common use case by accepting an amount, source currency, and target currency and returning the converted amount directly. This eliminates client-side conversion logic for applications where only the final converted value is needed. It is important to note that Frankfurter covers 32 currencies, and the Nigerian Naira is not among them. The ECB reference rate set covers major traded currencies primarily from developed markets. For applications specifically needing NGN exchange rates, a dedicated currency API with NGN support would be more appropriate. However, for Nigerian businesses primarily working with EUR, USD, GBP, CHF, JPY, and other major ECB-covered currencies, Frankfurter provides official-quality rate data at zero cost. The open-source nature of Frankfurter means the complete server-side codebase is publicly available. Organizations requiring guaranteed availability, data sovereignty, or control over the rate data pipeline can self-host Frankfurter on their own infrastructure, fetching directly from the ECB and serving through their own API endpoint. This self-hosting option is particularly relevant for Nigerian financial institutions subject to regulatory requirements about external data dependencies. For Nigerian developers building personal finance tools, business productivity applications, or learning projects involving international currency handling, Frankfurter offers immediate, zero-cost access to authoritative exchange rate data that is suitable for display and educational purposes without the overhead of account management.