Exchangerate.dev vs Helium

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

Uptime · 30d
Uptime · 90d71.6%0.0%
Uptime · 30d51.7%0.0%
P50 · ms336
P95 · ms807
Authnonenone
CORSyesno
HTTPSyesyes
Card requirednono
Commercial useunclearunclear
Data licenseUnverifiedUnverified
Free tierFree — limits not publishedFirst 50 queries per IP free, no key (paid API key beyond, ~$0.02/query)
Rate limit12 req/window · 11 remaining · resets 178351572050 free queries per IP subnet
In directory since2026-07-052026-07-05
operationalpartialdownno data

Exchangerate.dev vs Helium: common questions

Which is more reliable, Exchangerate.dev or Helium?

On our scheduled checks, Exchangerate.dev leads on measured uptime — Exchangerate.dev at 71.6% versus Helium at 0.0% over 90 days. These are our own probe results, not provider claims; the uptime bars above show the day-by-day record for both.

Do Exchangerate.dev and Helium need an API key?

Neither needs a paid key — Exchangerate.dev is callable with no signup, and Helium is callable with no signup. Both are quick to prototype with; rate limits still apply.

Can I call Exchangerate.dev and Helium from the browser?

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

Are Exchangerate.dev and Helium free for commercial use?

Exchangerate.dev has unclear commercial terms, and Helium 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.