Why PNG Instead of JPG?
PNG is a lossless format: it stores every pixel exactly, with no compression artefacts around text and sharp edges. That makes it the right choice when you need a clean screenshot of a page for a slide deck, a crisp logo or diagram lifted from a document, or an image you intend to edit further without the blurriness JPG introduces at each save. PNG also supports transparency, although pages exported here are rendered on a solid white background for predictable printing and pasting.
If your priority is the smallest possible file β for example to attach many pages to an email β JPG is usually smaller because it discards information the eye barely notices. This tool offers a standard and a high-resolution setting so you can balance crispness against file size; the high setting renders at 2.5Γ for print-grade detail.
Rendered Entirely in Your Browser
When you choose a file, pdf.js parses it and paints each page onto an off-screen canvas inside the page sandbox, which is then exported to PNG by the browser's own image encoder. No page image is ever sent anywhere β the only network request in the whole process is the one-time, cached download of the open-source library. Close the tab and the working memory is reclaimed immediately.