ISO 3166-2 API vs PostalCodes

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

Uptime · 30d
Uptime · 90d100%99.02%
Uptime · 30d100%98.3%
P50 · ms10561030
P95 · ms28652594
Authnonenone
CORSyesno
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

ISO 3166-2 API vs PostalCodes: common questions

Which is more reliable, ISO 3166-2 API or PostalCodes?

On our scheduled checks, ISO 3166-2 API leads on measured uptime — ISO 3166-2 API at 100% versus PostalCodes at 99.02% 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, ISO 3166-2 API or PostalCodes?

PostalCodes has the lower median latency in our checks — ISO 3166-2 API responds in 1056 ms versus PostalCodes at 1030 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 ISO 3166-2 API and PostalCodes need an API key?

Neither needs a paid key — ISO 3166-2 API is callable with no signup, and PostalCodes is callable with no signup. Both are quick to prototype with; rate limits still apply.

Can I call ISO 3166-2 API and PostalCodes from the browser?

Only ISO 3166-2 API is browser-friendly — it returns CORS headers over HTTPS. PostalCodes needs a server-side call or proxy, so factor that into which one fits a front-end project.

Are ISO 3166-2 API and PostalCodes free for commercial use?

ISO 3166-2 API has unclear commercial terms, and PostalCodes 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.