OpenHolidays API vs The Calendar
Same instrument, two spec sheets — measured, not claimed.
OpenHolidays API vs The Calendar: common questions
Which is more reliable, OpenHolidays API or The Calendar?
Both are neck-and-neck — OpenHolidays API 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, OpenHolidays API or The Calendar?
OpenHolidays API has the lower median latency in our checks — OpenHolidays API responds in 533 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 OpenHolidays API and The Calendar need an API key?
Neither needs a paid key — OpenHolidays API is callable with no signup, and The Calendar is callable with no signup. Both are quick to prototype with; rate limits still apply.
Can I call OpenHolidays API and The Calendar from the browser?
Yes — both OpenHolidays API and The Calendar 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 OpenHolidays API and The Calendar free for commercial use?
OpenHolidays API 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.