PDF to JPG Converter

How a PDF actually becomes a JPG

A PDF isn't a picture — it's a program that draws text and shapes onto a canvas when opened. To turn it into a JPG the tool has to render it. Under the hood, pdf.js walks each page's content stream, rasterises it into an off-screen HTML canvas, and then the canvas is exported as a JPEG via canvas.toBlob(). The "Quality Scale" slider simply tells the renderer how large the canvas should be relative to the page's PostScript points (72 pt per inch). A 1× render of a standard A4 page produces a 595 × 842 px image. At 2× you get 1190 × 1684 px — sharper text, roughly 4× the file size. At 4× a single page can push past 10 MB.

Which scale to choose

• 1× — screen preview, email attachment, website thumbnail. Roughly matches what you see in a PDF viewer at 100%.
• 2× — the default, and the sweet spot for most uses. Matches a Retina display and reads cleanly when zoomed in on a laptop.
• 3× — slide decks, Keynote embeds, marketing visuals where the image will be projected.
• 4× — print‑quality capture (approx. 288 DPI on A4). Use when the JPG will be printed at its real size or larger.

Going higher than 4× rarely adds visible detail because the source PDF often caps out at 300 DPI itself, especially for scanned documents. You'll just pay in file size and rendering time.

Why JPG is a compromise

JPEG was designed for photos, not text. Its block-based compression smudges sharp edges, which is exactly what page text, line art, and charts are made of. If you zoom into a JPG of a page you'll see faint coloured halos around letters — that's the DCT artefacts of a format that wasn't built for this job. When image quality matters more than file size, export to PNG instead. When searchability matters more than either, stay in PDF or run the JPGs through OCR afterwards (we have a tool for that too).

Good reasons to convert

• Uploading a page to a platform that only accepts images (Instagram, certain forum software, WhatsApp Status).
• Embedding a single PDF page into a Word document or slide deck without the whole file.
• Generating thumbnails for a document library or book cover previews.
• Creating a non‑editable record of a contract page for attaching to a chat message.

Privacy

Your PDF is parsed and rasterised by pdf.js inside the tab. The canvases and blobs live in your browser's memory, never on a server. Close the tab and the images are released.