IP Address API vs SLF
Same instrument, two spec sheets — measured, not claimed.
IP Address API vs SLF: common questions
Which is more reliable, IP Address API or SLF?
Both are neck-and-neck — IP Address API 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, IP Address API or SLF?
SLF has the lower median latency in our checks — IP Address API responds in 513 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 IP Address API and SLF need an API key?
Neither needs a paid key — IP Address API 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 IP Address API and SLF from the browser?
Yes — both IP Address API 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 IP Address API and SLF free for commercial use?
IP Address API 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.