IPWhois vs Postcodes.io
Same instrument, two spec sheets — measured, not claimed.
IPWhois vs Postcodes.io: common questions
Which is more reliable, IPWhois or Postcodes.io?
On our scheduled checks, Postcodes.io leads on measured uptime — IPWhois at —% versus Postcodes.io 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 IPWhois and Postcodes.io need an API key?
Postcodes.io needs no key, while IPWhois requires a free API key. If you want to start calling without signup, reach for Postcodes.io first.
Can I call IPWhois and Postcodes.io from the browser?
Only Postcodes.io is browser-friendly — it returns CORS headers over HTTPS. IPWhois needs a server-side call or proxy, so factor that into which one fits a front-end project.
Are IPWhois and Postcodes.io free for commercial use?
IPWhois has unclear commercial terms, and Postcodes.io 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.