Datamuse vs WhoisXML API Email Verification API

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

Uptime · 30d
Uptime · 90d92.2%0.0%
Uptime · 30d86.7%0.0%
P50 · ms180
P95 · ms926
AuthnoneapiKey
CORSnoyes
HTTPSyesyes
Card requirednono
Commercial useunclearunclear
Data licenseUnverifiedUnverified
Free tierFree — limits not publishedFree tier — API key required
Rate limitUnpublishedUnpublished
In directory since2026-07-052026-07-05
operationalpartialdownno data

Datamuse vs WhoisXML API Email Verification API: common questions

Which is more reliable, Datamuse or WhoisXML API Email Verification API?

On our scheduled checks, Datamuse leads on measured uptime — Datamuse at 92.2% versus WhoisXML API Email Verification API at 0.0% over 90 days. These are our own probe results, not provider claims; the uptime bars above show the day-by-day record for both.

Do Datamuse and WhoisXML API Email Verification API need an API key?

Datamuse needs no key, while WhoisXML API Email Verification API requires a free API key. If you want to start calling without signup, reach for Datamuse first.

Can I call Datamuse and WhoisXML API Email Verification API from the browser?

Only WhoisXML API Email Verification API is browser-friendly — it returns CORS headers over HTTPS. Datamuse needs a server-side call or proxy, so factor that into which one fits a front-end project.

Are Datamuse and WhoisXML API Email Verification API free for commercial use?

Datamuse 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.