Guerrilla Mail vs MailCheck.ai

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

Uptime · 30d
Uptime · 90d95.1%93.1%
Uptime · 30d98.3%93.3%
P50 · ms298272
P95 · ms1685842
Authnonenone
CORSyesyes
HTTPSyesyes
Card requirednono
Commercial useunclearunclear
Data licenseUnverifiedUnverified
Free tierFree — limits not publishedFree — limits not published
Rate limitUnpublished5 req/window · 4 remaining
In directory since2026-07-052026-07-05
operationalpartialdownno data

Guerrilla Mail vs MailCheck.ai: common questions

Which is more reliable, Guerrilla Mail or MailCheck.ai?

On our scheduled checks, Guerrilla Mail leads on measured uptime — Guerrilla Mail at 95.1% 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, Guerrilla Mail or MailCheck.ai?

MailCheck.ai has the lower median latency in our checks — Guerrilla Mail responds in 298 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 Guerrilla Mail and MailCheck.ai need an API key?

Neither needs a paid key — Guerrilla Mail 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 Guerrilla Mail and MailCheck.ai from the browser?

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

Guerrilla Mail 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.