Frankfurter
Free currency exchange rates from the European Central Bank. No key required.
🟢 Online · 1279 ms
98.87%
Unlimited, no key, no credit card
No key required
Free alternatives (live ranking)
- European Central Bank Rates — 🟢 Online · Unlimited, no key, no credit card
- Twelve Data — 🟢 Online · 800 calls/day, free key, no credit card
- Fixer.io — 🟢 Online · 100 calls/month, EUR base only, free key, no CC
Compare Frankfurter with…
- Frankfurter vs European Central Bank Rates — Unlimited, no key, no credit card
- Frankfurter vs Twelve Data — 800 calls/day, free key, no credit card
- Frankfurter vs Fixer.io — 100 calls/month, EUR base only, free key, no CC
Paid alternatives
- Open Exchange Rates — from $12/mo
Frequently Asked Questions
Does Frankfurter require an API key?
No, Frankfurter is freely accessible without registration or an API key.
What is Frankfurter's free tier?
Unlimited, no key, no credit card
Is Frankfurter currently online?
We check Frankfurter every hour. The current status is shown at the top of this page. You can also see the 30-day uptime history in the chart above.
Implementation notes
When to use Frankfurter
Frankfurter is the cleanest free currency API for EUR-centric applications. It sources data directly from the European Central Bank's official reference rates, updated each business day around 16:00 CET. No key, no account, and no stated rate limit makes it suitable for server-side caching setups.
Common pitfalls
- ECB rates are only updated on European Central Bank business days (weekdays excluding ECB holiday calendar). Weekend and holiday requests return the most recent available rate, not an error — which is correct behaviour, but your code should not assume 'latest' means 'today'.
- The ECB publishes rates against EUR only. Frankfurter supports cross-rate conversion (e.g., USD to GBP) by triangulating through EUR, but the `from` parameter is what sets the base. Setting `from=USD` triangulates correctly; setting `to=USD` and `from=GBP` also works.
- Historical data is available from 1999-01-04 (the Euro's introduction) but only covers the roughly 30 currencies that the ECB tracks. Major currencies like CNY (Chinese Yuan) are not included in the ECB dataset.
- There is no official rate-limit documentation. Frankfurter is self-hosted by the maintainer, and heavy polling has triggered informal throttling. Adding a `Cache-Control` max-age of at least 3,600 seconds on your end is good practice.
Quick start (bash)
curl "https://api.frankfurter.app/latest?from=USD&to=EUR,GBP,JPY"From our monitoring
Frankfurter is one of the most consistently available APIs in our finance category, with near-100% uptime in hourly monitoring. Response times average under 150ms.
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<a href="https://freeapi.watch/frankfurter"><img src="https://freeapi-builder.a10ayassine.workers.dev/badge/frankfurter.svg" alt="Frankfurter Status"/></a>Further reading
- Frankfurter API for Currency Conversion in Python — 5 minutes, Python, curl
- The Truth About Free API Tiers: Why 'Free' Often Isn't — A taxonomy of free tiers: truly free (no key), free-with-friction (key required), and the bait-and-switch pattern.
- 15 Free APIs Perfect for Hackathon Projects — Tested, no-key-required where possible, working in 2026. Pick from this list and start coding in minutes.