Currencylayer vs Twelve Data

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

Uptime · 30d
Uptime · 90d100%99.02%
Uptime · 30d100%98.3%
P50 · ms511253
P95 · ms9674851
AuthapiKeyapiKey
CORSnoyes
HTTPSyesyes
Card requirednono
Commercial useunclearunclear
Data licenseUnverifiedUnverified
Free tierFree tier — key may be requiredFree tier — API key required
Rate limitUnpublishedUnpublished
In directory since2026-07-052026-07-05
operationalpartialdownno data

Currencylayer vs Twelve Data: common questions

Which is more reliable, Currencylayer or Twelve Data?

On our scheduled checks, Currencylayer leads on measured uptime — Currencylayer 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, Currencylayer or Twelve Data?

Twelve Data has the lower median latency in our checks — Currencylayer responds in 511 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 Currencylayer and Twelve Data need an API key?

Both ask you to authenticate — Currencylayer uses an API key and Twelve Data uses an API key. Each key is free to obtain; the Auth and Card-required rows above spell out the signup terms.

Can I call Currencylayer and Twelve Data from the browser?

Only Twelve Data is browser-friendly — it returns CORS headers over HTTPS. Currencylayer needs a server-side call or proxy, so factor that into which one fits a front-end project.

Are Currencylayer and Twelve Data free for commercial use?

Currencylayer 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.