Frankfurter vs Marketstack

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

Uptime · 30d
Uptime · 90d88.2%100%
Uptime · 30d86.7%100%
P50 · ms370470
P95 · ms49864068
AuthnoneapiKey
CORSyesno
HTTPSyesyes
Card requirednono
Commercial useyesunclear
Data licensePublic data (ECB reference rates)Unverified
Free tierUnlimited — abuse-rate-limited onlyFree tier — key may be required
Rate limitUnpublished, generousUnpublished
In directory since2026-05-022026-07-05
operationalpartialdownno data

Frankfurter vs Marketstack: common questions

Which is more reliable, Frankfurter or Marketstack?

On our scheduled checks, Marketstack leads on measured uptime — Frankfurter at 88.2% versus Marketstack 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, Frankfurter or Marketstack?

Frankfurter has the lower median latency in our checks — Frankfurter responds in 370 ms versus Marketstack at 470 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 Frankfurter and Marketstack need an API key?

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

Can I call Frankfurter and Marketstack from the browser?

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

Are Frankfurter and Marketstack free for commercial use?

Frankfurter allows commercial use on its free tier, and Marketstack 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.