shipapis
StarSubmit an APISubmit API

ClinicalTrials.gov vs openFDA API

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

APIClinicalTrials.govNEW—openFDA APINEW—
Uptime · 30d
Uptime · 90d—%—%
Uptime · 30d—%—%
P50 · ms——
P95 · ms——
Authnonenone
CORSyesno
HTTPSyesyes
Card requirednono
Commercial useunclearunclear
Data licenseUnverifiedUnverified
Free tierFree — limits not publishedFree — limits not published
Rate limitUnpublishedUnpublished
In directory since2026-07-052026-07-05
operationalpartialdownno data

ClinicalTrials.gov vs openFDA API: common questions

Which is more reliable, ClinicalTrials.gov or openFDA API?

On our scheduled checks, openFDA API leads on measured uptime — ClinicalTrials.gov at —% versus openFDA API at —% 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 ClinicalTrials.gov and openFDA API need an API key?

Neither needs a paid key — ClinicalTrials.gov is callable with no signup, and openFDA API is callable with no signup. Both are quick to prototype with; rate limits still apply.

Can I call ClinicalTrials.gov and openFDA API from the browser?

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

Are ClinicalTrials.gov and openFDA API free for commercial use?

ClinicalTrials.gov has unclear commercial terms, and openFDA API 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.