The PaymentRequest method canMakePayment() determines whether or not the request is configured in a way that is compatible with at least one payment method supported by the user agent.

You can call this before calling show() to provide a streamlined user experience when the user's browser can't handle any of the payment methods you accept.

For instance, you might call canMakePayment() to determine if the browser will let the user pay using Payment Request API, and if it won't, you could fall back to another payment method, or offer a list of methods that aren't handled by Payment Request API (or even provide instructions for paying by mail or by phone).

None.

A Promise to a boolean value that resolves to true if the user agent supports any of the payment methods supplied when instantiating the request using the PaymentRequest constructor. If the payment can't be processed, the promise receives a value of false.

In the following example, is excerpted from a demo that asynchronously builds a PaymentRequest object for both Apple Pay and Example Pay. It wraps the call to canMakePayment() in feature detection, and calls an appropriate callback depending on the resolution of the Promise.

async function initPaymentRequest() {
  const details = {
    total: {
      label: "Total",
      amount: {
        currency: "USD",
        value: "0.00",
      },
    },
  };

  const supportsApplePay = new PaymentRequest(
    [{ supportedMethods: "https://apple.com/apple-pay" }],
    details,
  ).canMakePayment();

  // Supports Apple Pay?
  if (await supportsApplePay) {
    // show Apple Pay logo, for instance
    return;
  }

  // Otherwise, let's see if we can use Example Pay
  const supportsExamplePay = await new PaymentRequest(
    [{ supportedMethods: "https://example.com/pay" }],
    details,
  ).canMakePayment();

  if (supportsExamplePay) {
    // show Example Pay support
    return;
  }

  // Otherwise, make payments using HTML form element
}

• PaymentRequest.show()