Namedays Calendar vs PostStack

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

Uptime · 30d
Uptime · 90d91.2%100%
Uptime · 30d85.0%100%
P50 · ms4801066
P95 · ms27491890
AuthnoneapiKey
CORSnono
HTTPSyesyes
Card requirednono
Commercial useunclearunclear
Data licenseUnverifiedUnverified
Free tierFree — limits not publishedFree tier — key may be required
Rate limit60 req/window · 58 remainingUnpublished
In directory since2026-07-052026-07-05
operationalpartialdownno data

Namedays Calendar vs PostStack: common questions

Which is more reliable, Namedays Calendar or PostStack?

On our scheduled checks, PostStack leads on measured uptime — Namedays Calendar at 91.2% versus PostStack 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.

Which is faster, Namedays Calendar or PostStack?

Namedays Calendar has the lower median latency in our checks — Namedays Calendar responds in 480 ms versus PostStack at 1066 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 Namedays Calendar and PostStack need an API key?

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

Can I call Namedays Calendar and PostStack from the browser?

Neither sends browser-friendly CORS headers reliably, so call Namedays Calendar and PostStack from a server or proxy rather than client-side. The CORS and HTTPS rows above show exactly what we detected for each.

Are Namedays Calendar and PostStack free for commercial use?

Namedays Calendar has unclear commercial terms, and PostStack 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.