Lookup.im API vs Registrum API
Same instrument, two spec sheets — measured, not claimed.
Lookup.im API vs Registrum API: common questions
Which is more reliable, Lookup.im API or Registrum API?
On our scheduled checks, Registrum API leads on measured uptime — Lookup.im API at 99.04% versus Registrum API 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, Lookup.im API or Registrum API?
Registrum API has the lower median latency in our checks — Lookup.im API responds in 1128 ms versus Registrum API at 246 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 Lookup.im API and Registrum API need an API key?
Both ask you to authenticate — Lookup.im API uses an API key and Registrum API uses an API key. Each key is free to obtain; the Auth and Card-required rows above spell out the signup terms.
Can I call Lookup.im API and Registrum API from the browser?
Neither sends browser-friendly CORS headers reliably, so call Lookup.im API and Registrum API from a server or proxy rather than client-side. The CORS and HTTPS rows above show exactly what we detected for each.
Are Lookup.im API and Registrum API free for commercial use?
Lookup.im API has unclear commercial terms, and Registrum API 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.