IPWhois vs Zipcodestack

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

Uptime · 30d
Uptime · 90d—%—%
Uptime · 30d—%—%
P50 · ms
P95 · ms
AuthapiKeyapiKey
CORSyesyes
HTTPSnoyes
Card requirednono
Commercial useunclearunclear
Data licenseUnverifiedUnverified
Free tierFree tier — API key may be required for productionFree tier — API key required
Rate limitUnpublishedUnpublished
In directory since2026-07-052026-07-05
operationalpartialdownno data

IPWhois vs Zipcodestack: common questions

Which is more reliable, IPWhois or Zipcodestack?

On our scheduled checks, Zipcodestack leads on measured uptime — IPWhois at —% versus Zipcodestack 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 Zipcodestack need an API key?

Both ask you to authenticate — IPWhois uses an API key and Zipcodestack uses an API key. Each key is free to obtain; the Auth and Card-required rows above spell out the signup terms.

Can I call IPWhois and Zipcodestack from the browser?

Only Zipcodestack 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 Zipcodestack free for commercial use?

IPWhois has unclear commercial terms, and Zipcodestack 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.