Actually it's 348 bytes. <form action=/your-server-side-code method=POST><script class=stripe-button data-amount=999 data-description=Widget data-image=htt

Actually it's 348 bytes. <form action=/your-server-side-code method=POST><script class=stripe-button data-amount=999 data-description=Widget data-image=https://stripe.com/img/documentation/checkout/marketplace.png data-key=pk_test_6pRNASCoBOKtIshFeQd4XMUh data-locale=auto data-name=Stripe.com data-zip-code=true src=https://checkout.stripe.com/checkout.js></script></form>