PDF to Images

PDF.js handles the rasterization by parsing the page content stream and rendering each drawing operation onto a canvas scaled by the chosen preset. Text is rendered from embedded fonts where available, falling back to substitution fonts when a font is referenced but not embedded, which is why PDFs that rely on system fonts can look slightly different when rasterized in the browser versus opened in a desktop viewer. Images embedded in the PDF are rendered at whatever resolution they were stored at, then resampled to match the output canvas, so raster detail is bounded by the lower of embedded resolution and the chosen render scale.

Format choice matters. PNG is lossless: the output pixels match what the rasterizer produced exactly, which keeps text and line art crisp. JPEG re-encodes those pixels with DCT quantization, which softens text edges and can introduce ringing around high-contrast edges, but produces much smaller files for photo-heavy pages. In this tool JPEG is encoded at a fixed quality (about 0.92), so the size-versus-quality tradeoff is controlled by the resolution preset and the PNG/JPEG choice rather than a separate quality slider.

For delivery, you can export all rendered pages as separate files or bundle them in one ZIP, and you can limit the conversion to specific pages or a range. Pick a higher preset (High or Ultra) when you need sharp output for printing or zooming, and a lower preset (Draft or Standard) when you want small, fast images for on-screen use. Note that choosing a higher scale only helps up to the detail actually present in the PDF, upscaling cannot recover detail that was never there.