Currency Exchange — entry 003 of 18
Exchangeratesapi.io
Exchangeratesapi.io exposes real-time and historical exchange-rate lookups across 200+ currencies, layering on conversion, time-series, and fluctuation endpoints as customers move up its plan tiers, with the latter two gated to Professional and Business plans respectively. It explicitly documents CORS support for browser-side consumption, and, like its sister products, has moved its documentation and account management to APILayer's shared docs platform. Refresh cadence tightens from a daily free-tier interval up to 60-second updates on paid plans.
GreatAPIs Score
Embed this badge
<a href="https://greatapis.com/api/exchangeratesapi-io/"><img src="https://greatapis.com/badge/exchangeratesapi-io.svg" alt="Scored 75 on greatapis.com"></a>Auth quickstart
- Get a key at the provider
- Send it on every request as a header
Authorization: <key> - The exact header isn't documented — Authorization is a common default; confirm in the provider's docs.
Your key is stored only in this browser (localStorage) and sent directly to the API — never to greatapis.
Developer reference
100 API calls/month on Free plan, 10,000/month on Basic, 100,000/month on Professional, 500,000/month on Business, custom/unlimited on Custom plan