Adoptium vs Userstack
Same instrument, two spec sheets — measured, not claimed.
Adoptium vs Userstack: common questions
Which is more reliable, Adoptium or Userstack?
On our scheduled checks, Adoptium leads on measured uptime — Adoptium at 100% versus Userstack at 99.02% 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, Adoptium or Userstack?
Userstack has the lower median latency in our checks — Adoptium responds in 476 ms versus Userstack at 443 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 Adoptium and Userstack need an API key?
Adoptium needs no key, while Userstack requires a free API key. If you want to start calling without signup, reach for Adoptium first.
Can I call Adoptium and Userstack from the browser?
Yes — both Adoptium and Userstack 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 Adoptium and Userstack free for commercial use?
Adoptium has unclear commercial terms, and Userstack 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.