In short
This tool saves the pages of a PDF as PNG or JPG images: to drop a page into a presentation, publish it on a website or send it to someone who does not open PDFs. Choose the pages to export and the resolution: 72 dpi for a light preview, 150 dpi for the screen, 300 dpi for printing. PNG suits text and diagrams, JPG suits pages full of photos. Each image follows the way the page is displayed, and its longest side is limited to 8,000 pixels. Several images are delivered in a ZIP; with several PDFs, all their pages are exported into the same ZIP. The pages are rendered in your browser.