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arcsecond.io vs Keen IO

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

APIarcsecond.ioHEALTHY92Keen IOHEALTHY90
Uptime · 30d
Uptime · 90d100%100%
Uptime · 30d100%100%
P50 · ms587667
P95 · ms15781461
AuthnoneapiKey
CORSyesno
HTTPSyesyes
Card requirednono
Commercial useunclearunclear
Data licenseUnverifiedUnverified
Free tierFree — limits not publishedFree tier — key may be required
Rate limitUnpublishedUnpublished
In directory since2026-07-052026-07-05
operationalpartialdownno data

arcsecond.io vs Keen IO: common questions

Which is more reliable, arcsecond.io or Keen IO?

Both are neck-and-neck — arcsecond.io and Keen IO 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, arcsecond.io or Keen IO?

arcsecond.io has the lower median latency in our checks — arcsecond.io responds in 587 ms versus Keen IO at 667 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 arcsecond.io and Keen IO need an API key?

arcsecond.io needs no key, while Keen IO requires a free API key. If you want to start calling without signup, reach for arcsecond.io first.

Can I call arcsecond.io and Keen IO from the browser?

Only arcsecond.io is browser-friendly — it returns CORS headers over HTTPS. Keen IO needs a server-side call or proxy, so factor that into which one fits a front-end project.

Are arcsecond.io and Keen IO free for commercial use?

arcsecond.io has unclear commercial terms, and Keen IO 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.