SLA Uptime Calculator vs staffSign

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

Uptime · 30d
Uptime · 90d—%—%
Uptime · 30d—%—%
P50 · ms
P95 · ms
AuthnoneapiKey
CORSyesno
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

SLA Uptime Calculator vs staffSign: common questions

Which is more reliable, SLA Uptime Calculator or staffSign?

On our scheduled checks, staffSign leads on measured uptime — SLA Uptime Calculator at —% versus staffSign at —% over 90 days. These are our own probe results, not provider claims; the uptime bars above show the day-by-day record for both.

Do SLA Uptime Calculator and staffSign need an API key?

SLA Uptime Calculator needs no key, while staffSign requires a free API key. If you want to start calling without signup, reach for SLA Uptime Calculator first.

Can I call SLA Uptime Calculator and staffSign from the browser?

Only SLA Uptime Calculator is browser-friendly — it returns CORS headers over HTTPS. staffSign needs a server-side call or proxy, so factor that into which one fits a front-end project.

Are SLA Uptime Calculator and staffSign free for commercial use?

SLA Uptime Calculator has unclear commercial terms, and staffSign 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.