Narwhal API
Use Narwhal when currency conversion shares an application with commodities, economics, calendars, and predictions.
Exchange rate APIs compared
Compare seven APIs for currency conversion, daily history, official rates, and broader data access. Check the rate type, currency coverage, and observation time before choosing an integration.
Decision
Choose Narwhal for FX alongside commodities, economics, calendars, and predictions under one key and MCP. Choose exchangerate.dev for dedicated pair coverage and official rates, or another specialist when its currencies, history, or licensing fit better.
Provider shortlist
This shortlist compares developer APIs rather than executable trading quotes; indicative, daily reference, and official published rates serve different purposes. Narwhal API and exchangerate.dev are owned and operated by Nusantara Ventures, LLC.
exchangerate.dev
Choose exchangerate.dev for currency-focused applications needing a large pair catalogue and government-published official rates.
Fixer
Consider Fixer for a dedicated currency service with conversion and historical time-series workflows.
Open Exchange Rates
Consider Open Exchange Rates when broad currency coverage and long daily histories are priorities.
ExchangeRate-API
Consider ExchangeRate-API for simple currency lookups, pair conversion, and a separate open-access option.
XE Currency Data API
Consider XE Currency Data API for commercially licensed currency data with central-bank, crypto, and precious-metal options.
Currencylayer
Consider Currencylayer for currency and precious-metal codes with historical exchange-rate access.
Compare the options
Best fit is not feature parity. Check the evidence and limitation together.
| Provider | Best for | Evidence checked | Important limitation |
|---|---|---|---|
| Narwhal API | Use Narwhal when currency conversion shares an application with commodities, economics, calendars, and predictions. | Its FX contract includes current rates, decimal-safe conversion, and daily history through REST and hosted MCP. | Check supported currencies, freshness, and missing historical observations; reference rates do not establish executable trading prices. |
| exchangerate.dev | Choose exchangerate.dev for currency-focused applications needing a large pair catalogue and government-published official rates. | The API documents 10,296 pairs, conversion, daily history, official tables with valid periods, REST, and MCP. | Official tables only support pairs their authorities publish; market rates are indicative, and history varies by pair. |
| Fixer | Consider Fixer for a dedicated currency service with conversion and historical time-series workflows. | Published material lists 170 currencies, history from January 1999, current rates, conversion, and fluctuation endpoints. | Confirm base-currency flexibility, update intervals, and required endpoint access before choosing the service. |
| Open Exchange Rates | Consider Open Exchange Rates when broad currency coverage and long daily histories are priorities. | Its documentation describes more than 200 currencies and daily history from 1999, alongside current rates, conversion, and time-series products. | Verify base-currency options and historical availability for each series, along with access to conversion and time-series endpoints. |
| ExchangeRate-API | Consider ExchangeRate-API for simple currency lookups, pair conversion, and a separate open-access option. | Its published catalogue lists 165 currencies and documents all-rates, pair-conversion, enriched-data, and historical endpoints. | Update cadence, history, attribution, and redistribution conditions differ between access options. |
| XE Currency Data API | Consider XE Currency Data API for commercially licensed currency data with central-bank, crypto, and precious-metal options. | XE documents fiat currencies, alternate central-bank rates, conversion, and history extending to 1998. | Check the licensed usage, caching terms, refresh frequency, and exact series rather than treating headline coverage as fiat-only. |
| Currencylayer | Consider Currencylayer for currency and precious-metal codes with historical exchange-rate access. | Its published coverage lists 168 codes, including precious metals, with historical rates from 1999. | Published update-frequency descriptions differ, so confirm the cadence, base-currency options, and endpoint access required. |
Choose by requirement
FX with broader data
Start with Narwhal when currency conversion is one part of a broader data application. Its key and MCP access also cover commodities, economics, calendars, and predictions.
Dedicated pairs and official rates
Compare exchangerate.dev when pair coverage and official-rate tables are central. Select the authority and valid period for official lookups rather than substituting an indicative market rate.
Specialist coverage and history
Compare Fixer, Open Exchange Rates, ExchangeRate-API, XE Currency Data API, and Currencylayer for the exact currencies, history, and licensing needed. Verify observation intervals and base-currency access before switching.
Sources and review date
Each detailed provider page lists the first-party documentation used, its evidence boundaries, and its review date.
Reviewed: