PNG costs more space than JPG: at 150 DPI, the statement page of our sample was 220 KB as PNG and 68 KB as JPG. What you get for the extra size is an exact copy of the pixels, with no faint smudging around letters and lines. Whether that is worth it depends on what you do with the image next.
When the extra size pays off
- You will edit the image. Crop it, add arrows, paste it into a document and save again: a JPG loses a little each time it is saved, a PNG does not.
- The page is line work. Forms, tables, diagrams and small print have hard edges, which is exactly where JPG compression shows first.
- The page has logos or charts, whose flat colors stay solid instead of picking up speckles.
When a JPG is the better deal
Pages with photos. Our full-page photo was 1.0 MB as PNG and 206 KB as JPG at 150 DPI, and 2.7 MB as PNG at 300 DPI. For an upload form with a size limit, or for sending a page in a chat, switch “Convert to” to JPG or use PDF to JPG. For a mostly text page the difference is smaller in absolute terms: the list page of the sample was 94 KB as PNG against 28 KB as JPG.
One document, three resolutions
The sample was Letter size, so each page came out 612 × 792 pixels at Screen (72 DPI), 1275 × 1650 at Standard (150 DPI) and 2550 × 3300 at Print (300 DPI). At 300 DPI the statement page was 539 KB and the list page 273 KB as PNG. PNG was also the quicker format to produce: at 150 DPI each page took about a fifth of a second or less, against up to 0.8 seconds for JPG.
Each page becomes its own file, named after the PDF and the page number, and the “Download all … as ZIP” button saves them in one archive. Text in a PNG is part of the picture, so it cannot be selected or searched. To turn PNG images back into a document, use PNG to PDF.