Keyvalue vs Userstack

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

Uptime · 30d
Uptime · 90d86.3%99.02%
Uptime · 30d80.0%98.3%
P50 · ms855443
P95 · ms20513029
AuthnoneapiKey
CORSyesyes
HTTPSyesyes
Card requirednono
Commercial useunclearunclear
Data licenseUnverifiedUnverified
Free tierFree — limits not publishedFree tier — API key required
Rate limitUnpublishedUnpublished
In directory since2026-07-052026-07-05
operationalpartialdownno data

Keyvalue vs Userstack: common questions

Which is more reliable, Keyvalue or Userstack?

On our scheduled checks, Userstack leads on measured uptime — Keyvalue at 86.3% 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, Keyvalue or Userstack?

Userstack has the lower median latency in our checks — Keyvalue responds in 855 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 Keyvalue and Userstack need an API key?

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

Can I call Keyvalue and Userstack from the browser?

Yes — both Keyvalue 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 Keyvalue and Userstack free for commercial use?

Keyvalue 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.