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?
Both are neck-and-neck — AQICN and Hong Kong Observatory each measure 100% uptime over 90 days on our probe schedule. Reliability here is verified from our own scheduled checks; use the 30-day bars above to see which has been steadier lately.
Which is faster, AQICN or Hong Kong Observatory?
AQICN has the lower median latency in our checks — AQICN responds in 224 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 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.