Base64 image data URIs are one of those web techniques that look like a magic shortcut the first time you use them. Instead of referencing an external file: <img src= "/logo.png" alt= "Logo" > you can put the image bytes directly in the document as text: <img src= "data:image/png;base64,iVBORw0KGgoAAAANSUhEUg..." alt= "Logo" > That can be useful. It can also make a page slower, harder to cache, and more annoying to maintain. ...