Open Notify vs Satellite Passes

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

Uptime · 30d
Uptime · 90d71.6%99.02%
Uptime · 30d65.0%98.3%
P50 · ms241976
P95 · ms42983243
Authnonenone
CORSyesyes
HTTPSnoyes
Card requirednono
Commercial useunclearunclear
Data licensen/aUnverified
Free tierUnlimited (volunteer-run)Free — limits not published
Rate limitPlease be gentleUnpublished
In directory since2026-05-022026-07-05
operationalpartialdownno data

Open Notify vs Satellite Passes: common questions

Which is more reliable, Open Notify or Satellite Passes?

On our scheduled checks, Satellite Passes leads on measured uptime — Open Notify at 71.6% versus Satellite Passes 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, Open Notify or Satellite Passes?

Open Notify has the lower median latency in our checks — Open Notify responds in 241 ms versus Satellite Passes at 976 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 Open Notify and Satellite Passes need an API key?

Neither needs a paid key — Open Notify is callable with no signup, and Satellite Passes is callable with no signup. Both are quick to prototype with; rate limits still apply.

Can I call Open Notify and Satellite Passes from the browser?

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

Are Open Notify and Satellite Passes free for commercial use?

Open Notify has unclear commercial terms, and Satellite Passes 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.