How can I find out whether a PDF has embedded thumbnails?

Q: How can I check whether my document has embedded thumbails?


The easiest way to investigate whether a PDF has thumbs is to open it in CosEdit (, then traverse to any page (e.g., the first page at trailer/Root/Pages/Kids/0) and look for a stream named Thumb (which should be an image). That image stream is the page’s embedded thumbnail.

If you’d prefer to test for this programmatically, you can do so using Page.GetThumb: