ip.app vs Postcodes.io

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

Uptime · 30d
Uptime · 90d—%—%
Uptime · 30d—%—%
P50 · ms
P95 · ms
Authnonenone
CORSyesyes
HTTPSyesyes
Card requirednono
Commercial useunclearunclear
Data licenseUnverifiedService MIT-licensed; postcode data license unverified
Free tierFree — limits not publishedFree — no key required
Rate limitUnpublishedUnpublished (no key; fair use)
In directory since2026-07-052026-07-05
operationalpartialdownno data

ip.app vs Postcodes.io: common questions

Which is more reliable, ip.app or Postcodes.io?

On our scheduled checks, Postcodes.io leads on measured uptime — ip.app 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 ip.app and Postcodes.io need an API key?

Neither needs a paid key — ip.app is callable with no signup, and Postcodes.io is callable with no signup. Both are quick to prototype with; rate limits still apply.

Can I call ip.app and Postcodes.io from the browser?

Yes — both ip.app and Postcodes.io 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.app and Postcodes.io free for commercial use?

ip.app 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.