Free Currency & Crypto API
Foreign-exchange rates built on European Central Bank reference data, amount conversion between any two currencies, and live crypto prices with 24-hour change from CoinGecko — all behind one key.
Endpoints
| Method | Endpoint | Description | Source |
|---|---|---|---|
GET |
/api/v1/finance/exchange-rates?base=USD&symbols=EUR,GBP |
Latest FX rates | Frankfurter |
GET |
/api/v1/finance/convert?from=&to=&amount= |
Convert an amount between currencies | Frankfurter |
GET |
/api/v1/finance/crypto/prices?ids=bitcoin,ethereum&vs=usd |
Live crypto prices and 24h change | CoinGecko |
Full request/response details for every endpoint are in the API documentation.
Example request
curl "https://freeopenapi.dev/api/v1/finance/crypto/prices?ids=bitcoin,ethereum&vs=usd" \
-H "X-Api-Key: YOUR_API_KEY"
Works the same with ?apiKey=... as a query parameter. Every response carries
X-RateLimit-Limit / X-RateLimit-Remaining headers so you can track your budget.
Frequently asked questions
Is the exchange-rate and crypto API really free?
Yes. The free tier includes 100 requests per day and only requires a verified email address — no credit card. Paid Pro and Business tiers raise the daily limit.
How fresh are the crypto prices?
Crypto prices are cached for a few minutes at most; if the upstream provider is briefly unavailable, the API serves the last known price and marks it stale so you always get an answer.
Which currencies are supported?
All major fiat currencies covered by the ECB reference rates, and any coin listed on CoinGecko for crypto prices.
How do I get an API key?
Request a key with your email address on the Docs page, click the confirmation link we send you, and your key is active immediately on the free tier.