Kickbox vs MailCheck.ai

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

Uptime · 30d
Uptime · 90d100%93.1%
Uptime · 30d100%93.3%
P50 · ms592272
P95 · ms3630842
Authnonenone
CORSyesyes
HTTPSyesyes
Card requirednono
Commercial useunclearunclear
Data licenseUnverifiedUnverified
Free tierFree — open disposable-address checkFree — limits not published
Rate limitUnpublished5 req/window · 4 remaining
In directory since2026-07-052026-07-05
operationalpartialdownno data

Kickbox vs MailCheck.ai: common questions

Which is more reliable, Kickbox or MailCheck.ai?

On our scheduled checks, Kickbox leads on measured uptime — Kickbox at 100% versus MailCheck.ai at 93.1% 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, Kickbox or MailCheck.ai?

MailCheck.ai has the lower median latency in our checks — Kickbox responds in 592 ms versus MailCheck.ai at 272 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 Kickbox and MailCheck.ai need an API key?

Neither needs a paid key — Kickbox is callable with no signup, and MailCheck.ai is callable with no signup. Both are quick to prototype with; rate limits still apply.

Can I call Kickbox and MailCheck.ai from the browser?

Yes — both Kickbox and MailCheck.ai 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 Kickbox and MailCheck.ai free for commercial use?

Kickbox has unclear commercial terms, and MailCheck.ai 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.