Kickbox vs mailboxlayer

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

Uptime · 30d
Uptime · 90d—%—%
Uptime · 30d—%—%
P50 · ms
P95 · ms
AuthnoneapiKey
CORSyesno
HTTPSyesyes
Card requirednono
Commercial useunclearunclear
Data licenseUnverifiedUnverified
Free tierFree — open disposable-address checkFree tier — key may be required
Rate limitUnpublishedUnpublished
In directory since2026-07-052026-07-05
operationalpartialdownno data

Kickbox vs mailboxlayer: common questions

Which is more reliable, Kickbox or mailboxlayer?

On our scheduled checks, mailboxlayer leads on measured uptime — Kickbox at —% versus mailboxlayer 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 Kickbox and mailboxlayer need an API key?

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

Can I call Kickbox and mailboxlayer from the browser?

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

Are Kickbox and mailboxlayer free for commercial use?

Kickbox has unclear commercial terms, and mailboxlayer 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.