Frankfurter

Frankfurter tracks daily exchange rates from 30+ central banks and official sources, covering 160 active currencies.

The public API lives at api.frankfurter.dev. No keys. Use anywhere. You can also self-host.

Rates

Fetch the latest exchange rates.

curl https://api.frankfurter.dev/v2/rates

Change the base currency with base. Filter target currencies with quote.

curl https://api.frankfurter.dev/v2/rates?base=USD&quotes=EUR,GBP

Historical Rates

Look up rates for a specific date.

curl https://api.frankfurter.dev/v2/rates?date=1999-01-04

Time Series

Fetch rates over a period with from and to.

curl https://api.frankfurter.dev/v2/rates?from=2024-01-01&to=2024-01-05&quotes=USD

Tip: Narrowing down currencies keeps responses small. For large date ranges, request NDJSON to stream results line by line.

Grouping

Downsample a time series with group.

curl https://api.frankfurter.dev/v2/rates?from=2024-01-01&group=month

Filtering by Provider

Scope to specific providers with providers.

curl https://api.frankfurter.dev/v2/rates?providers=ECB

By default, rates are blended across all providers. Use providers to retrieve rates from a specific source.

CSV Output

Rates are also available as CSV. Append .csv to the path or set the Accept header to text/csv.

curl https://api.frankfurter.dev/v2/rates.csv

NDJSON Output

For large responses, request NDJSON (newline-delimited JSON) by setting the Accept header to application/x-ndjson. Each line is one independent JSON object, useful for streaming large time series without buffering the entire response.

curl -H "Accept: application/x-ndjson" \
  "https://api.frankfurter.dev/v2/rates?from=2024-01-01"

Rate

Get the rate for a single currency pair. Optionally add date or providers.

curl https://api.frankfurter.dev/v2/rate/EUR/USD

Currency

Get details and provider coverage for a single currency.

curl https://api.frankfurter.dev/v2/currency/EUR

Currencies

Get available currencies with provider coverage.

curl https://api.frankfurter.dev/v2/currencies

Providers

List the data sources behind the API.

curl https://api.frankfurter.dev/v2/providers

Conversion

Fetch the rate and convert in your own code.

function convert(base, quote, amount) {
  fetch(`https://api.frankfurter.dev/v2/rates?base=${base}&quotes=${quote}`)
    .then((resp) => resp.json())
    .then((data) => {
      const result = (amount * data[0].rate).toFixed(2);
      alert(`${amount} ${base} = ${result} ${quote}`);
    });
  }

convert("EUR", "USD", 10);

Click or tap the snippet to run it.

Errors

The API returns standard HTTP status codes with a JSON body.

{
  "message": "Could not find currency ABC"
}

400

Invalid parameter or malformed request.

404

Currency, rate, or resource not found.

422

Request understood but cannot be processed.

Self-Hosting

You can self-host with Docker. See the deploy guide for production setup and API key configuration.

FAQ

Is the API free for commercial use?

Yes, absolutely.

Does the API have any call limits?

There are no limits. For high-volume use, consider caching responses or self-hosting.

Is the v1 API being retired?

No. The v1 API will continue to work. See the v1 documentation.

What is the privacy policy of the API?

The API itself does not collect personal data. However, the public app runs behind Cloudflare for performance, and Cloudflare will collect some basic information for analytics. This does not apply if you run the API privately.

Can I suggest a new data source?

If you know of a provider we should add, please open an issue and include a link to the source. We're looking for non-commercial sources that publish current and historical rates at least daily.

How accurate are the rates?

It depends on your use case. If you need official reference rates for reporting or compliance, filter by a specific provider. The numbers will match what that institution publishes. If you're converting prices for display, say, localizing an e-commerce site, the default blended rates work well. They're drawn from multiple sources and are accurate for practical use, though the last decimal places may shift slightly as new data comes in.

Why is it called Frankfurter?

Frankfurt is home to the European Central Bank, the original data source of this project.