PostalCodes vs PostcodeData.nl

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

Uptime · 30d
Uptime · 90d—%—%
Uptime · 30d—%—%
P50 · ms
P95 · ms
Authnonenone
CORSnoyes
HTTPSyesno
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

PostalCodes vs PostcodeData.nl: common questions

Which is more reliable, PostalCodes or PostcodeData.nl?

On our scheduled checks, PostcodeData.nl leads on measured uptime — PostalCodes at —% versus PostcodeData.nl 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 PostalCodes and PostcodeData.nl need an API key?

Neither needs a paid key — PostalCodes is callable with no signup, and PostcodeData.nl is callable with no signup. Both are quick to prototype with; rate limits still apply.

Can I call PostalCodes and PostcodeData.nl from the browser?

Neither sends browser-friendly CORS headers reliably, so call PostalCodes and PostcodeData.nl from a server or proxy rather than client-side. The CORS and HTTPS rows above show exactly what we detected for each.

Are PostalCodes and PostcodeData.nl free for commercial use?

PostalCodes has unclear commercial terms, and PostcodeData.nl 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.