The iTunes image tag is one of the few tags added by Apple with any substantial value over the base RSS 2.0 specification. In this article I cover the Apple Podcast artwork requirements for using this tag.
The image you include here must be a minimum size of 1400 x 1400 pixels and a maximum size of 3000 x 3000 pixels. Apple Podcasts allows either JPEG or PNG format at 72 dpi. The file extension must be either .jpg or .png.
Be sure your podcast artwork does not contain an alpha channel, which is a transparency layer. This last requirement is similar to App Store submission guidelines for iOS apps. The easy way to avoid this is to use a JPEG file. If you submit artwork to Apple Podcasts as a PNG file, make sure there’s no alpha channel when saving from image editing software.
The recommendation for meeting Apple Podcast artwork requirements is to use the maximum size of 3000×3000 so that the image shows up well on all screens. This is one tag you should definitely include to make sure your podcast is differentiated from the default image in the Apple Podcast app.
The tag to include Apple Podcast artwork in your RSS feed should look like this:<itunes:image>http://www.YourPodcastURL.com/YourImage.jpg</itunes:image>
