Code

<!DOCTYPE html>
<html lang="en" dir="ltr">
  <head>
    <meta charset="utf-8">
    <title></title>
  </head>
  <body>
    <picture>
      <source srcset="img/awesomeWebPImage.webp" type="image/webp">
      <source srcset="img/creakyOldJPEG.jpg" type="image/jpeg">
      <img src="img/creakyOldJPEG.jpg" alt="Alt Text!">
    </picture>
  </body>
</html>