shipapis
StarSubmit an APISubmit API

Resend vs The Calendar

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

APIResendDEAD0The CalendarHEALTHY90
Uptime · 30d
Uptime · 90d0.0%100%
Uptime · 30d0.0%100%
P50 · ms—588
P95 · ms—3550
AuthapiKeynone
CORSnoyes
HTTPSyesyes
Card requirednono
Commercial useunclearunclear
Data licenseUnverifiedUnverified (US federal list per 5 U.S.C. § 6103)
Free tierFree tier — API key requiredFree, no auth (per site)
Rate limitUnpublishedNone stated (site advertises no rate limit)
In directory since2026-07-052026-07-05
operationalpartialdownno data

Resend vs The Calendar: common questions

Which is more reliable, Resend or The Calendar?

On our scheduled checks, The Calendar leads on measured uptime — Resend at 0.0% versus The Calendar 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 Resend and The Calendar need an API key?

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

Can I call Resend and The Calendar from the browser?

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

Are Resend and The Calendar free for commercial use?

Resend has unclear commercial terms, and The Calendar 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.