Adyen Checkout API vs Fixer
Same instrument, two spec sheets — measured, not claimed.
Adyen Checkout API vs Fixer: common questions
Which is more reliable, Adyen Checkout API or Fixer?
On our scheduled checks, Adyen Checkout API leads on measured uptime — Adyen Checkout API at 100% versus Fixer at 99.02% 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, Adyen Checkout API or Fixer?
Adyen Checkout API has the lower median latency in our checks — Adyen Checkout API responds in 418 ms versus Fixer at 481 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 Adyen Checkout API and Fixer need an API key?
Both ask you to authenticate — Adyen Checkout API uses an API key and Fixer 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 Adyen Checkout API and Fixer from the browser?
Only Fixer is browser-friendly — it returns CORS headers over HTTPS. Adyen Checkout API needs a server-side call or proxy, so factor that into which one fits a front-end project.
Are Adyen Checkout API and Fixer free for commercial use?
Adyen Checkout API has unclear commercial terms, and Fixer 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.