caldays vs Tumblr
Same instrument, two spec sheets — measured, not claimed.
caldays vs Tumblr: common questions
Which is more reliable, caldays or Tumblr?
Both are neck-and-neck — caldays and Tumblr 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, caldays or Tumblr?
caldays has the lower median latency in our checks — caldays responds in 149 ms versus Tumblr at 208 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 caldays and Tumblr need an API key?
caldays needs no key, while Tumblr requires OAuth. If you want to start calling without signup, reach for caldays first.
Can I call caldays and Tumblr from the browser?
Yes — both caldays and Tumblr 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 caldays and Tumblr free for commercial use?
caldays has unclear commercial terms, and Tumblr 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.