shipapis
StarSubmit an APISubmit API

CustomGPT.ai vs WhoisXML API Email Verification API

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

APICustomGPT.aiDEAD0WhoisXML API Email Verification APIDEAD0
Uptime · 30d
Uptime · 90d0.0%0.0%
Uptime · 30d0.0%0.0%
P50 · ms——
P95 · ms——
AuthapiKeyapiKey
CORSyesyes
HTTPSyesyes
Card requirednono
Commercial useunclearunclear
Data licenseUnverifiedUnverified
Free tierFree tier — API key requiredFree tier — API key required
Rate limitUnpublishedUnpublished
In directory since2026-07-052026-07-05
operationalpartialdownno data

CustomGPT.ai vs WhoisXML API Email Verification API: common questions

Which is more reliable, CustomGPT.ai or WhoisXML API Email Verification API?

Both are neck-and-neck — CustomGPT.ai and WhoisXML API Email Verification API each measure 0.0% 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.

Do CustomGPT.ai and WhoisXML API Email Verification API need an API key?

Both ask you to authenticate — CustomGPT.ai uses an API key and WhoisXML API Email Verification 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 CustomGPT.ai and WhoisXML API Email Verification API from the browser?

Yes — both CustomGPT.ai and WhoisXML API Email Verification API send CORS headers over HTTPS, so front-end code can fetch either directly with no backend proxy. That makes them easy to swap in a client-side app while you compare responses.

Are CustomGPT.ai and WhoisXML API Email Verification API free for commercial use?

CustomGPT.ai has unclear commercial terms, and WhoisXML API Email Verification 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.