HelloSalut vs SLF

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 — limits not publishedFree — static file, no key
Rate limitUnpublishedUnpublished
In directory since2026-07-052026-07-05
operationalpartialdownno data

HelloSalut vs SLF: common questions

Which is more reliable, HelloSalut or SLF?

On our scheduled checks, SLF leads on measured uptime — HelloSalut at —% versus SLF 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 HelloSalut and SLF need an API key?

Neither needs a paid key — HelloSalut is callable with no signup, and SLF is callable with no signup. Both are quick to prototype with; rate limits still apply.

Can I call HelloSalut and SLF from the browser?

Yes — both HelloSalut and SLF 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 HelloSalut and SLF free for commercial use?

HelloSalut has unclear commercial terms, and SLF 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.