Why choose PNG for PDF pages
PNG is a lossless picture format: it keeps every pixel exactly, so text, thin lines, charts, tables and diagrams stay crisp with no blurry blocks around the letters. That makes PNG the best choice when a PDF page will be placed in a presentation, a website, a design or a document where sharpness matters.
What happens when you convert
Each PDF page is drawn as a PDF viewer would show it and saved as its own PNG file, named with the page number. You choose the sharpness: 96 DPI for screens, 150 DPI for normal use, or 300 DPI for printing and zooming. Multi-page PDFs are downloaded as one ZIP with all the PNG files inside, or one by one from the file list.
When PNG is better than JPG — and when it is not
PNG wins for pages with text, charts, maps and line drawings. For pages full of photographs, PNG files become much larger than JPG without a visible gain, so PDF to JPG is usually the better choice there.
Common problems and how to fix them
The files are very large: choose 150 DPI instead of 300, or use PDF to JPG for photo pages. You only need part of a page, such as one chart: convert the page, then cut out the part with Crop Image. The PDF needs a password: it must be unlocked first.
Good habits
Pick the lowest DPI that still looks sharp where the image will be used, keep the original PDF, and name the exported pictures clearly if you send them to others.