REST Countries vs WhoisXML API Email Verification API
Same instrument, two spec sheets — measured, not claimed.
REST Countries vs WhoisXML API Email Verification API: common questions
Which is more reliable, REST Countries or WhoisXML API Email Verification API?
On our scheduled checks, WhoisXML API Email Verification API leads on measured uptime — REST Countries at —% versus WhoisXML API Email Verification API at —% 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 REST Countries and WhoisXML API Email Verification API need an API key?
REST Countries needs no key, while WhoisXML API Email Verification API requires a free API key. If you want to start calling without signup, reach for REST Countries first.
Can I call REST Countries and WhoisXML API Email Verification API from the browser?
Yes — both REST Countries 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 REST Countries and WhoisXML API Email Verification API free for commercial use?
REST Countries allows commercial use on its free tier, 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.