AQICN vs Hong Kong Observatory
Same instrument, two spec sheets — measured, not claimed.
AQICN vs Hong Kong Observatory: common questions
Which is more reliable, AQICN or Hong Kong Observatory?
On our scheduled checks, AQICN leads on measured uptime — AQICN at 100% versus Hong Kong Observatory at 98.9% 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, AQICN or Hong Kong Observatory?
AQICN has the lower median latency in our checks — AQICN responds in 267 ms versus Hong Kong Observatory at 1678 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 AQICN and Hong Kong Observatory need an API key?
Hong Kong Observatory needs no key, while AQICN requires a free API key. If you want to start calling without signup, reach for Hong Kong Observatory first.
Can I call AQICN and Hong Kong Observatory from the browser?
Only Hong Kong Observatory is browser-friendly — it returns CORS headers over HTTPS. AQICN needs a server-side call or proxy, so factor that into which one fits a front-end project.
Are AQICN and Hong Kong Observatory free for commercial use?
AQICN 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.