PostalCodes vs What3Words

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

Uptime · 30d
Uptime · 90d99.02%100%
Uptime · 30d98.3%100%
P50 · ms1030391
P95 · ms25941181
AuthnoneapiKey
CORSnono
HTTPSyesyes
Card requirednono
Commercial useunclearunclear
Data licenseUnverifiedUnverified
Free tierFree — limits not publishedFree tier — key may be required
Rate limitUnpublishedUnpublished
In directory since2026-07-052026-07-05
operationalpartialdownno data

PostalCodes vs What3Words: common questions

Which is more reliable, PostalCodes or What3Words?

On our scheduled checks, What3Words leads on measured uptime — PostalCodes at 99.02% versus What3Words at 100% 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, PostalCodes or What3Words?

What3Words has the lower median latency in our checks — PostalCodes responds in 1030 ms versus What3Words at 391 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 PostalCodes and What3Words need an API key?

PostalCodes needs no key, while What3Words requires a free API key. If you want to start calling without signup, reach for PostalCodes first.

Can I call PostalCodes and What3Words from the browser?

Neither sends browser-friendly CORS headers reliably, so call PostalCodes and What3Words 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 What3Words free for commercial use?

PostalCodes has unclear commercial terms, and What3Words 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.