npm Registry vs SLA Uptime Calculator

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

Uptime · 30d
Uptime · 90d—%—%
Uptime · 30d—%—%
P50 · ms
P95 · ms
Authnonenone
CORSyesyes
HTTPSyesyes
Card requirednono
Commercial useunclearunclear
Data licenseUnverifiedUnverified
Free tierFree (public registry)Free — limits not published
Rate limitUnpublished (bulk scraping discouraged)Unpublished
In directory since2026-07-052026-07-05
operationalpartialdownno data

npm Registry vs SLA Uptime Calculator: common questions

Which is more reliable, npm Registry or SLA Uptime Calculator?

On our scheduled checks, SLA Uptime Calculator leads on measured uptime — npm Registry at —% versus SLA Uptime Calculator 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 npm Registry and SLA Uptime Calculator need an API key?

Neither needs a paid key — npm Registry is callable with no signup, and SLA Uptime Calculator is callable with no signup. Both are quick to prototype with; rate limits still apply.

Can I call npm Registry and SLA Uptime Calculator from the browser?

Yes — both npm Registry and SLA Uptime Calculator 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 npm Registry and SLA Uptime Calculator free for commercial use?

npm Registry has unclear commercial terms, and SLA Uptime Calculator 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.