Exchange Rates API vs GOV.UK Pay API

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

Uptime · 30d
Uptime · 90d—%—%
Uptime · 30d—%—%
P50 · ms
P95 · ms
AuthnoneapiKey
CORSnono
HTTPSyesyes
Card requirednono
Commercial useunclearunclear
Data licenseUnverifiedUnverified
Free tierFree — limits not publishedFree tier — API key required
Rate limitUnpublishedUnpublished
In directory since2026-07-052026-07-05
operationalpartialdownno data

Exchange Rates API vs GOV.UK Pay API: common questions

Which is more reliable, Exchange Rates API or GOV.UK Pay API?

On our scheduled checks, GOV.UK Pay API leads on measured uptime — Exchange Rates API at —% versus GOV.UK Pay API 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 Exchange Rates API and GOV.UK Pay API need an API key?

Exchange Rates API needs no key, while GOV.UK Pay API requires a free API key. If you want to start calling without signup, reach for Exchange Rates API first.

Can I call Exchange Rates API and GOV.UK Pay API from the browser?

Neither sends browser-friendly CORS headers reliably, so call Exchange Rates API and GOV.UK Pay API from a server or proxy rather than client-side. The CORS and HTTPS rows above show exactly what we detected for each.

Are Exchange Rates API and GOV.UK Pay API free for commercial use?

Exchange Rates API has unclear commercial terms, and GOV.UK Pay API 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.