Callook.info vs Micro User Service

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

Uptime · 30d
Uptime · 90d100%18.6%
Uptime · 30d100%0.0%
P50 · ms437231
P95 · ms1156827
AuthnoneapiKey
CORSyesno
HTTPSyesyes
Card requirednono
Commercial useunclearunclear
Data licenseUnverified (data from public FCC ULS records)Unverified
Free tierFree — limits not publishedFree tier — key may be required
Rate limitUnpublishedUnpublished
In directory since2026-07-052026-07-05
operationalpartialdownno data

Callook.info vs Micro User Service: common questions

Which is more reliable, Callook.info or Micro User Service?

On our scheduled checks, Callook.info leads on measured uptime — Callook.info at 100% versus Micro User Service at 18.6% 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, Callook.info or Micro User Service?

Micro User Service has the lower median latency in our checks — Callook.info responds in 437 ms versus Micro User Service at 231 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 Callook.info and Micro User Service need an API key?

Callook.info needs no key, while Micro User Service requires a free API key. If you want to start calling without signup, reach for Callook.info first.

Can I call Callook.info and Micro User Service from the browser?

Only Callook.info is browser-friendly — it returns CORS headers over HTTPS. Micro User Service needs a server-side call or proxy, so factor that into which one fits a front-end project.

Are Callook.info and Micro User Service free for commercial use?

Callook.info has unclear commercial terms, and Micro User Service 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.