How to create image thumbnails for remote PDFs?

You can generate image thumbnails for remote PDF documents when using Cloudinary's 'fetch' URLs by adding the 'format' transformation parameter ('f' for URLs). For example, adding 'f_jpg': https://res.cloudinary.com/demo/image/fetch/w_150,h_150,c_thumb,f_jpg/https://res.cloudinary.com/demo/image/upload/multi_page_pdf.pdf

Note that requesting the generation of the thumbnail also caches the remote PDF to your product environment while setting its type to 'fetch'. The thumbnail itself is created as a derived image.

You can read more about PDF handling in this Cloudinary blog article.