ImprovMX API vs Kickbox

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

Uptime · 30d
Uptime · 90d0.0%100%
Uptime · 30d0.0%100%
P50 · ms592
P95 · ms3630
AuthapiKeynone
CORSyesyes
HTTPSyesyes
Card requirednono
Commercial useunclearunclear
Data licenseUnverifiedUnverified
Free tierFree tier — API key requiredFree — open disposable-address check
Rate limit301 req/window · 300 remaining · resets 1783526520Unpublished
In directory since2026-07-052026-07-05
operationalpartialdownno data

ImprovMX API vs Kickbox: common questions

Which is more reliable, ImprovMX API or Kickbox?

On our scheduled checks, Kickbox leads on measured uptime — ImprovMX API at 0.0% versus Kickbox 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.

Do ImprovMX API and Kickbox need an API key?

Kickbox needs no key, while ImprovMX API requires a free API key. If you want to start calling without signup, reach for Kickbox first.

Can I call ImprovMX API and Kickbox from the browser?

Yes — both ImprovMX API and Kickbox 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 ImprovMX API and Kickbox free for commercial use?

ImprovMX API has unclear commercial terms, and Kickbox 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.