ExchangeRate-API (open) vs Frankfurter
Same instrument, two spec sheets — measured, not claimed.
ExchangeRate-API (open) vs Frankfurter: common questions
Which is more reliable, ExchangeRate-API (open) or Frankfurter?
On our scheduled checks, ExchangeRate-API (open) leads on measured uptime — ExchangeRate-API (open) at 100% versus Frankfurter at 88.2% over 90 days. These are our own probe results, not provider claims; the uptime bars above show the day-by-day record for both.
Which is faster, ExchangeRate-API (open) or Frankfurter?
ExchangeRate-API (open) has the lower median latency in our checks — ExchangeRate-API (open) responds in 221 ms versus Frankfurter at 370 ms (P50). Tail latency (P95) is in the table above; for most workloads the median is the number that shapes how the API feels.
Do ExchangeRate-API (open) and Frankfurter need an API key?
Neither needs a paid key — ExchangeRate-API (open) is callable with no signup, and Frankfurter is callable with no signup. Both are quick to prototype with; rate limits still apply.
Can I call ExchangeRate-API (open) and Frankfurter from the browser?
Yes — both ExchangeRate-API (open) and Frankfurter send CORS headers over HTTPS, so front-end code can fetch either directly with no backend proxy. That makes them easy to swap in a client-side app while you compare responses.
Are ExchangeRate-API (open) and Frankfurter free for commercial use?
ExchangeRate-API (open) has unclear commercial terms, and Frankfurter allows commercial use on its free tier. We track service terms and the data license as separate fields — see the Commercial use and Data license rows above, and confirm both before shipping either in a paid product.