PDF to PNG

Converting a PDF to PNG turns each page into an image — a faithful picture of the page, exactly as it would print, that can be dropped into a slide, a document, or a message.

PNG is the right target when the page contains text, diagrams or line art. It compresses without discarding anything, so a thin line stays a thin line and small type stays legible.

The trade is size. A lossless render of a text page is much larger than the JPG equivalent, which is why PDF to JPG exists alongside this tool.

The two formats were designed around different assumptions, and a PDF page is squarely in PNG's territory.

JPEG compresses by discarding detail the eye is unlikely to notice, and it works on blocks of pixels. That is ideal for a photograph, where colour changes gradually and the discarded information genuinely is invisible. It is poor for a hard black line on white, because the sharp transition is exactly what the algorithm smooths — which shows up as faint grey haze around text, usually called ringing.

PNG compresses by finding repetition and encoding it exactly. A page that is mostly white with black text is enormously repetitive, so it compresses well and loses nothing. The same algorithm on a photograph finds almost no repetition, which is why photographic PNGs are so large.

The practical rule: if the page is a scanned photograph, use JPG. If it has text, a chart, a table or a diagram, use PNG. If it has both and you cannot decide, PNG is the safer default — it will be bigger, but nothing will be degraded.

Resolution matters more than format for legibility. A page rendered too small produces text that is unreadable in any format, and no amount of lossless compression rescues detail that was never rendered.