JPG or PNG? Picking the Right Format When Converting PDF Pages
July 26, 2026 · PDF Tools
Converting a PDF page to an image always presents the same two choices — JPG or PNG, and a DPI number — and the defaults are not always right. The good news is that the correct answer follows from two questions: what is on the page, and where is the image going?
How the two formats differ
JPG compresses by discarding information the eye is unlikely to miss, and it is superb at photographs: smooth gradients, natural textures, no hard edges. Its weakness is exactly what documents are full of — sharp, high-contrast boundaries like black letters on white paper. Compressed hard, those edges grow faint halos and speckle, which is why heavily compressed screenshots of text look dirty.
PNG is lossless: every pixel survives exactly. Text stays surgically crisp at any compression-free size, and PNG supports transparency, which JPG does not. Its cost shows on photographs, where 'every pixel exactly' is expensive — a photo-heavy page saved as PNG can be several times larger than a visually identical JPG.
The rule of thumb
- Mostly text, tables, diagrams or line art → PNG. Edges stay clean and the file is often smaller than a high-quality JPG of the same page.
- Mostly photographs → JPG. The compression is built for exactly this content and the savings are large.
- Mixed pages → decide by what must look perfect. If the text is the point, PNG; if the photos are the point, JPG at high quality.
- Need transparency (a stamp, a logo, a signature to overlay) → PNG, no contest.
Choosing a DPI
DPI decides how many pixels the page is rendered into, and it scales file size and rendering time quadratically: 300 DPI produces four times the pixels of 150 DPI. For viewing on screens, chat messages and slide decks, 96–150 DPI is plenty. For print, or when small footnotes must stay legible, use 300 DPI. Going beyond 300 rarely helps — you are magnifying the limits of the source document, not adding detail.
Three practical scenarios
- A contract page for a chat thread: PNG at 150 DPI. Text stays readable, the file stays light, and messaging apps preview it inline.
- A brochure page full of photography for a website: JPG at 150 DPI, then let the site's image pipeline resize it.
- A form to print and sign: PNG or JPG at 300 DPI, so the printed result does not look soft.
One caution applies to every conversion: an image of a page is a picture, not a document. The text in it can no longer be searched, selected or read by a screen reader. Convert pages when an image is genuinely what the destination needs — and keep the original PDF as the document of record.