Is it safe to use to display images?

I've learned that it's possible to embed an image in an HTML page like so, instead of linking to a separate image file:

<a href="data:image/png;base64,...(blah blah base64-encoded png goes here)..."
  width="70" height="38" alt="image embedded using base64 encoding!"></a>

Is this "safe", as in will all modern browsers be able to view the image, as long as I stick to common formats like PNG/JPG? Are there any downsides, other than base64-encoding the image increasing the image size by a bit?

Thanks.