PDF to PNG - Convert PDF Pages to Lossless Images

What This Converter Does

This tool renders each PDF page onto a canvas with pdf.js — the engine Firefox uses to display PDFs — and encodes the result as PNG, entirely inside this browser tab. PNG is the format to choose when what is on the page is text, tables, diagrams, charts or line art, and the reason is in how the two formats compress. JPG transforms the image in 8×8 blocks and discards the high-frequency components first; a hard black-on-white edge is nothing but high frequency, so every letter comes back with a faint grey halo around it, and thin table rules can smear away entirely. PNG stores pixels losslessly, so a rendered page is exactly the pixels pdf.js drew — which also means a page can be re-cropped, annotated or re-encoded later without accumulating damage the way a re-saved JPG does. The trade-off is size, and it is not small: on a photographic page PNG can be five to ten times the size of a JPG at a quality nobody would complain about, because lossless compression has almost nothing to exploit in continuous-tone imagery. Resolution behaves the same way here as anywhere in PDF. The format's internal unit is 1/72 inch, so a page rendered at scale 1 is 72 DPI — the size the document declares and too coarse for body text. 150 DPI is the readable default; 300 DPI is print and OCR territory at four times the pixel count. Pages are rendered and encoded one at a time so long documents do not have to fit in memory at once, and each page is painted on white first, because PDF pages carry no background of their own and a transparent one renders as black in most viewers.