# Currency Converter

> Convert currencies at reference rates.

Currency Converter is a browser-based exchange calculator in MyBox. It converts an amount between currencies using free, keyless reference rates and shows the rate date from the provider.

## Features

- Amount field, searchable from/to currency selectors, and a swap action.
- Defaults to USD to IDR with an amount of 1 on a first visit.
- The last-used pair is remembered across visits; up to five recent pairs are saved newest first.
- Copy the formatted result to the clipboard with a confirmation.
- Preload a conversion with `?from=USD&to=IDR&amount=100`.
- Results use the browser locale and the target currency's minor unit; IDR is shown without decimals.
- The page shows the unit rate, rate date, source, and the notice "Reference rates; actual bank or exchange rates differ."

## Sources and caching

- Primary: [Frankfurter](https://frankfurter.dev/) publishes ECB reference rates for about 30 currencies and updates on working days.
- Fallback: [ExchangeRate-API](https://www.exchangerate-api.com/) is used when the primary source is unavailable.
- Rates are cached in the browser for one hour. An expired cache is used as an offline fallback and labelled with its rate date.
- These are reference rates; bank or exchange rates will differ.

## Privacy

- Recent pairs, the last-used pair, and cached rates stay in your browser.
- The app sends only the selected base currency to the rate providers.

## Notes

- This Markdown twin is static. Open the interactive page for live rates and conversion.

## Related

- [Currency Converter](https://mybox.id/currency-converter)
- [Apps](https://mybox.id/apps): Every app with a short description.