PDF to JPG turns every page of a PDF into its own standalone image file — a process usually called rasterizing a page, because a fixed layout built from vector text, embedded fonts, and line art gets flattened into a plain grid of pixels. That is a different job from compressing a PDF: compression keeps the file a PDF while shrinking it, while this turns each page into a JPG or PNG so it behaves like any other photo. The distinction matters for what you can do with the result afterward — an image drops straight into a slide, a chat window, or a thumbnail gallery, but it can no longer be searched or edited as text the way the original PDF could.
Resolution is the setting most worth thinking about before you convert. Standard resolution (roughly 72 DPI) keeps files small and loads fast, which is fine for a quick visual reference or something you will only ever view on a screen. High (roughly 144 DPI) is a safer default for most documents. Ultra (roughly 216 DPI) renders each page at three times the base pixel dimensions, and it is worth the larger file size for anything with small print, dense tables, or line art you might zoom into or print — once a page becomes a fixed-pixel image, you cannot add back detail that was never rendered in the first place.
JPG and PNG behave differently once a page becomes pixels. JPG applies lossy compression, which works well for pages with photographs, gradients, or shaded illustrations, but it can leave soft blur or blocky artifacts around crisp black text and thin ruled lines, especially at lower quality settings. PNG is lossless — every pixel from the rendered page is kept exactly, so a scanned page, a page of dense body text, or a technical diagram with fine strokes looks noticeably cleaner as a PNG than as a JPG saved at a low setting. If the page you are converting is mostly text or line art rather than a photo, choosing PNG (or at minimum bumping the resolution up) is the better call than trying to fix blur after the fact.
Every page in the source document is converted — there is no per-page picker on this tool, so a ten-page PDF produces ten images. Single-page files download immediately as one image; anything with more than one page is automatically bundled into a ZIP so you are not stuck saving files one at a time. The whole pipeline — reading the PDF, drawing each page to a canvas, and encoding the result — runs locally in your browser using PDF.js, a JavaScript rendering engine, so nothing is ever sent to a server. People reach for this conversion to pull a single page out of a long report for a slide deck, to generate a quick visual preview of a document before sending it onward, to share one page on a messaging app or forum that will not accept a PDF attachment, or to archive a scanned page as a standalone image file alongside a photo library.
