How to display Base64 images in HTML?

You need to specify the correct Content-type, Content-encoding and charset.

Like

 data:image/jpeg;charset=utf-8;base64,

according to the syntax of the data URI scheme:

 data:[<media type>][;charset=<character set>][;base64],<data>

My suspect is of course the actual Base64 data. Otherwise it looks good to me. See this fiddle where a similar scheme is working. You may try specifying the character set.

<div>
  <p>Taken from wikpedia</p>
  <img src="data:image/png;base64, iVBORw0KGgoAAAANSUhEUgAAAAUA
    AAAFCAYAAACNbyblAAAAHElEQVQI12P4//8/w38GIAXDIBKE0DHxgljNBAAO
        9TXL0Y4OHwAAAABJRU5ErkJggg==" alt="Red dot" />
</div>

You can try this Base64 decoder to see if your Base64 data is correct or not.