DFlight API vs Hong Kong Observatory

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

Uptime · 30d
Uptime · 90d11.8%100%
Uptime · 30d0.0%100%
P50 · ms3191415
P95 · ms6683670
Authnonenone
CORSnoyes
HTTPSyesyes
Card requirednono
Commercial useunclearunclear
Data licenseUnverifiedHKO open data (see terms of use)
Free tierFree — limits not publishedFree, no key
Rate limitUnpublishedUnpublished
In directory since2026-07-052026-07-05
operationalpartialdownno data

DFlight API vs Hong Kong Observatory: common questions

Which is more reliable, DFlight API or Hong Kong Observatory?

On our scheduled checks, Hong Kong Observatory leads on measured uptime — DFlight API at 11.8% versus Hong Kong Observatory 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, DFlight API or Hong Kong Observatory?

DFlight API has the lower median latency in our checks — DFlight API responds in 319 ms versus Hong Kong Observatory at 1415 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 DFlight API and Hong Kong Observatory need an API key?

Neither needs a paid key — DFlight API is callable with no signup, and Hong Kong Observatory is callable with no signup. Both are quick to prototype with; rate limits still apply.

Can I call DFlight API and Hong Kong Observatory from the browser?

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

Are DFlight API and Hong Kong Observatory free for commercial use?

DFlight API has unclear commercial terms, and Hong Kong Observatory 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.