Country.is vs SLF

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

Uptime · 30d
Uptime · 90d100%100%
Uptime · 30d100%100%
P50 · ms189213
P95 · ms643668
Authnonenone
CORSyesyes
HTTPSyesyes
Card requirednono
Commercial useunclearunclear
Data licenseUnverifiedUnverified
Free tierFree, no API key requiredFree — static file, no key
Rate limitUnpublishedUnpublished
In directory since2026-07-052026-07-05
operationalpartialdownno data

Country.is vs SLF: common questions

Which is more reliable, Country.is or SLF?

Both are neck-and-neck — Country.is and SLF each measure 100% uptime over 90 days on our probe schedule. Reliability here is verified from our own scheduled checks; use the 30-day bars above to see which has been steadier lately.

Which is faster, Country.is or SLF?

Country.is has the lower median latency in our checks — Country.is responds in 189 ms versus SLF at 213 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 Country.is and SLF need an API key?

Neither needs a paid key — Country.is 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 Country.is and SLF from the browser?

Yes — both Country.is 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 Country.is and SLF free for commercial use?

Country.is 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.