IP Address API vs ViaCep
Same instrument, two spec sheets — measured, not claimed.
IP Address API vs ViaCep: common questions
Which is more reliable, IP Address API or ViaCep?
On our scheduled checks, ViaCep leads on measured uptime — IP Address API at —% versus ViaCep 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 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.