Open Notify vs TensorFeed

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

Uptime · 30d
Uptime · 90d71.6%100%
Uptime · 30d65.0%100%
P50 · ms241306
P95 · ms4298752
Authnonenone
CORSyesyes
HTTPSnoyes
Card requirednono
Commercial useunclearunclear
Data licensen/aUnverified
Free tierUnlimited (volunteer-run)Free — no key (static JSON feed endpoints)
Rate limitPlease be gentle120 req/window · 119 remaining · resets 60
In directory since2026-05-022026-07-05
operationalpartialdownno data

Open Notify vs TensorFeed: common questions

Which is more reliable, Open Notify or TensorFeed?

On our scheduled checks, TensorFeed leads on measured uptime — Open Notify at 71.6% versus TensorFeed at 100% 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 TensorFeed?

Open Notify has the lower median latency in our checks — Open Notify responds in 241 ms versus TensorFeed at 306 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 TensorFeed need an API key?

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

Can I call Open Notify and TensorFeed from the browser?

Only TensorFeed 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 TensorFeed free for commercial use?

Open Notify has unclear commercial terms, and TensorFeed 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.