<blockquote> File download as .zip will not auto unzip. </blockquote> Zip is a compression format. There's dedicated software to compress files in zip format, and also to unpack them. Firefox is a web browser and doesn't do zip/unzip. <blockquote> Have searched to convert .zip to .pdf </blockquote> You cannot 'convert' a zip file to pdf. It's like comparing apples and oranges. You'd need to unpack the zip file with software capable of doing that to restore the original pdf.