Kickbox vs mailboxlayer

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

Uptime · 30d
Uptime · 90d100%100%
Uptime · 30d100%100%
P50 · ms592316
P95 · ms36302634
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?

Both are neck-and-neck — Kickbox and mailboxlayer each measure 100% uptime over 90 days on our probe schedule. Reliability here is verified from our own scheduled checks; use the 30-day bars above to see which has been steadier lately.

Which is faster, Kickbox or mailboxlayer?

mailboxlayer has the lower median latency in our checks — Kickbox responds in 592 ms versus mailboxlayer at 316 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 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.