USD/PLN Currency Conversion API

Frequently Asked Questions

• Can I use the Convert Currency API for commercial purposes?

  Yes, but you must have a premium subscription. Commercial use of the Convert Currency API is not permitted on the free tier. See our pricing page to choose a plan that fits your needs.

• How do I get an API key and start using the Convert Currency API?

  Sign up for a free account to instantly get your API key, then pass it in the X-Api-Key header on every request. The documentation above includes ready-to-run examples in cURL, Python, JavaScript, Node.js, and more.

• What happens if I exceed my quota for the month?

  Your API requests will simply be denied once you hit your monthly quota — you will never be charged more than the plan you signed up for. To increase your quota, you can upgrade your plan any time on our pricing page.

• What happens if a request to the Convert Currency API fails?

  The API responds with a standard HTTP status code and a JSON error message describing the problem. See our error codes reference for the full list of codes and how to resolve each one, or contact support if you need help.

• How do I convert an amount from one currency to another?

  Send a GET request with three required parameters: have (the 3-character code of the currency you currently hold, e.g. GBP), want (the 3-character code you want to convert to, e.g. AUD), and amount (the quantity to convert). To pull the underlying rates directly instead, see the Exchange Rate API.

• What does the Convert Currency API response include?

  It returns a JSON object with old_amount and old_currency echoing your input, new_amount and new_currency giving the converted result, and a timestamp (Unix seconds) indicating when the exchange rate used for the conversion was applied. See the error codes page for what is returned on a failed request.

• How fresh are the exchange rates, and which currencies are supported?

  All supported currencies are available on the free tier, which returns once-daily exchange rates; premium plans add real-time rates. The API converts between fiat currencies only (for crypto, use a dedicated crypto endpoint). Each response includes a timestamp for the exchange rate used. For historical rates, see the Exchange Rate API.

• What are some use cases for the Convert Currency API?

  It is ideal for displaying localized prices in e-commerce checkouts, building travel budgeting tools, and normalizing multi-currency invoices or financial reports. For tracking how much a currency pair fluctuates over time, pair it with the Currency Volatility API.