PostStack vs The Calendar
Same instrument, two spec sheets — measured, not claimed.
PostStack vs The Calendar: common questions
Which is more reliable, PostStack or The Calendar?
Both are neck-and-neck — PostStack and The Calendar 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, PostStack or The Calendar?
The Calendar has the lower median latency in our checks — PostStack responds in 1066 ms versus The Calendar at 588 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 PostStack and The Calendar need an API key?
The Calendar needs no key, while PostStack requires a free API key. If you want to start calling without signup, reach for The Calendar first.
Can I call PostStack and The Calendar from the browser?
Only The Calendar is browser-friendly — it returns CORS headers over HTTPS. PostStack needs a server-side call or proxy, so factor that into which one fits a front-end project.
Are PostStack and The Calendar free for commercial use?
PostStack 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.