PNG is the image format to choose when edges must stay crisp. A page with small text, a chart, a floor plan, a table of results or a logo looks blurry and smudged as a JPG, because JPG is built for photos and softens hard edges. As a PNG every letter and line stays exactly as sharp as in the PDF. That is why PNG is the better pick for screenshots in a presentation, diagrams in a report, an answer key on a class slide or a page you want to annotate in another app.
Add your PDF and you see every page as a thumbnail. Leave the selection empty to convert the whole document, or tap only the pages you need; you can also type them, such as 1-3, 7. Choose the resolution: Normal draws pages at 150 dots per inch, which is plenty for screens and keeps files reasonable, and High uses 300 dots per inch for printing or zooming in on fine detail. Each page becomes its own image, named after your PDF and the page number, so the order is never lost.
Turn on Transparent background when you want to place a page on top of something else. Instead of white paper, the empty areas of the page stay see-through, so a logo, a signature or a diagram drawn in a PDF can sit on a coloured slide or a website without a white box around it. Pages that have their own white background, such as most scans, stay white because the white is part of the page itself.
Pages are drawn by a PDF engine inside your browser, so your file never leaves this device and nothing is uploaded. With several pages you can download each image separately or get them all at once in a ZIP file, and on a phone you can share an image straight to an app or save it to your gallery.
PNG files are larger than JPG. For photos and scanned pages, PDF to JPG gives much smaller files that look the same. To go the other way and turn images into a PDF, use Image to PDF. Locked PDFs need to be opened with Unlock PDF first.