IP Address API vs ViaCep

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

Uptime · 30d
Uptime · 90d100%98.0%
Uptime · 30d100%98.3%
P50 · ms513651
P95 · ms37362277
Authnonenone
CORSyesyes
HTTPSyesyes
Card requirednono
Commercial useunclearunclear
Data licenseUnverifiedUnverified
Free tierFree — limits not publishedFree — limits not published
Rate limitUnpublishedUnpublished
In directory since2026-07-052026-07-05
operationalpartialdownno data

IP Address API vs ViaCep: common questions

Which is more reliable, IP Address API or ViaCep?

On our scheduled checks, IP Address API leads on measured uptime — IP Address API at 100% versus ViaCep at 98.0% over 90 days. These are our own probe results, not provider claims; the uptime bars above show the day-by-day record for both.

Which is faster, IP Address API or ViaCep?

IP Address API has the lower median latency in our checks — IP Address API responds in 513 ms versus ViaCep at 651 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 ViaCep need an API key?

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

Can I call IP Address API and ViaCep from the browser?

Yes — both IP Address API and ViaCep 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 ViaCep free for commercial use?

IP Address API has unclear commercial terms, and ViaCep 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.