Open Topo Data vs Postali

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

Uptime · 30d
Uptime · 90d—%—%
Uptime · 30d—%—%
P50 · ms
P95 · ms
Authnonenone
CORSnoyes
HTTPSyesyes
Card requirednono
Commercial useunclearunclear
Data licenseUnverifiedUnverified
Free tierFree — limits not publishedFree — no key, no signup, no monthly limit (per site)
Rate limitUnpublishedUnpublished
In directory since2026-07-052026-07-05
operationalpartialdownno data

Open Topo Data vs Postali: common questions

Which is more reliable, Open Topo Data or Postali?

On our scheduled checks, Postali leads on measured uptime — Open Topo Data at —% versus Postali 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 Open Topo Data and Postali need an API key?

Neither needs a paid key — Open Topo Data is callable with no signup, and Postali is callable with no signup. Both are quick to prototype with; rate limits still apply.

Can I call Open Topo Data and Postali from the browser?

Only Postali is browser-friendly — it returns CORS headers over HTTPS. Open Topo Data needs a server-side call or proxy, so factor that into which one fits a front-end project.

Are Open Topo Data and Postali free for commercial use?

Open Topo Data has unclear commercial terms, and Postali 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.