Exchange Rates API vs Twelve Data

Same instrument, two spec sheets — measured, not claimed.

Uptime · 30d
Uptime · 90d100%99.02%
Uptime · 30d100%98.3%
P50 · ms810253
P95 · ms41624851
AuthnoneapiKey
CORSyesyes
HTTPSyesyes
Card requirednono
Commercial useunclearunclear
Data licenseUnverifiedUnverified
Free tierFree — limits not publishedFree tier — API key required
Rate limitUnpublishedUnpublished
In directory since2026-07-052026-07-05
operationalpartialdownno data

Exchange Rates API vs Twelve Data: common questions

Which is more reliable, Exchange Rates API or Twelve Data?

On our scheduled checks, Exchange Rates API leads on measured uptime — Exchange Rates API at 100% versus Twelve Data at 99.02% 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, Exchange Rates API or Twelve Data?

Twelve Data has the lower median latency in our checks — Exchange Rates API responds in 810 ms versus Twelve Data at 253 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 Exchange Rates API and Twelve Data need an API key?

Exchange Rates API needs no key, while Twelve Data requires a free API key. If you want to start calling without signup, reach for Exchange Rates API first.

Can I call Exchange Rates API and Twelve Data from the browser?

Yes — both Exchange Rates API and Twelve Data 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 Exchange Rates API and Twelve Data free for commercial use?

Exchange Rates API has unclear commercial terms, and Twelve Data has unclear commercial terms. 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.