How to convert PDF to JPG without blurry output

Why does converted output look blurry?

A PDF page is usually a set of instructions: draw this glyph here, stroke this line, place this image in this rectangle. Text and vector art in that form have no resolution at all — the reader renders them freshly at whatever size you view them.

A JPG has exactly one resolution, fixed the moment it is created. Conversion therefore has to pick a size, and that choice is irreversible. Enlarging the result afterwards does not add detail; it interpolates between pixels that are already there, which is why an upscaled JPG looks soft and slightly plastic.

Many converters quietly default to 72 or 96 DPI because it produces small files fast. On a modern high-density display that is roughly half the pixels the screen can show, which reads immediately as blur.

So the rule is simple and it only applies once: choose the resolution before converting, and choose it for the largest use you have in mind.

What DPI should you actually pick?

DPI here means how many pixels are produced per inch of the original page. An A4 page at 150 DPI comes out around 1240 × 1754 pixels; at 300 DPI, around 2480 × 3508.

File sizes assume a text-heavy page at JPEG quality 0.8. A page that is mostly photograph runs two to three times larger. Note that doubling DPI quadruples the pixel count — 600 DPI is sixteen times the data of 150 DPI, which is why it is worth reserving for cases that genuinely need it.

Should the output be JPG or PNG?

This choice matters more than most people expect, and the right answer depends on what is on the page rather than on any general preference.

JPEG compresses by discarding detail the eye is bad at noticing. That works beautifully on photographs and badly on hard edges — which is exactly what text is. At moderate quality settings you get faint halos around letterforms, most visible on small type against a white background.

PNG is lossless. Text stays perfectly crisp, and for a page of black type on white the file is often *smaller* than the JPEG, because PNG compresses large flat areas extremely well. On a page of photographs, PNG can be five times larger.

• Text documents, forms, invoices, contracts, line art → PNG.
• Photographs, scanned photos, magazine pages, artwork → JPG.
• Mixed pages → JPG at quality 0.85 or higher, which keeps the halos below the level anyone notices.
• Anything with transparency → PNG. JPEG has no alpha channel and will fill transparent areas with solid black or white.

How do you convert just one page?

Most conversions produce one image per page, which is rarely what you want from a 40-page document. There are two routes.

Convert everything and keep the page you need. Simple, works everywhere, and briefly produces forty files you have to sift through.

Or extract the page first with Split PDF, then convert the single-page result. This is the better habit for long documents: the intermediate file is a legitimate artifact you may want anyway, and you never have to identify page 23 by thumbnail.

If what you actually want is a picture of one region rather than a whole page — a chart, a diagram, a signature block — convert at 300 DPI and then crop with the Image Cropper. Cropping after a high-DPI render keeps far more detail than rendering small and enlarging.

Why is the converted image enormous?

A 300 DPI A4 page is roughly 8.7 million pixels. That is a larger image than most phone cameras produce, and it is easy to generate a hundred megabytes from a modest PDF without realising.

If the output is unwieldy, the fix is almost never to convert again at a lower quality — it is to decide honestly what the images are for. Screen use does not need 300 DPI. If you already have the large files and need them smaller, run them through the Image Compressor, which lets you see the size before you commit, or resize them with the Image Resizer.

One thing to avoid: converting at low DPI to save space and then enlarging when you discover you needed print quality. That path produces the worst possible result, because the detail was discarded at step one and no amount of processing brings it back.

Does converting to JPG remove the text layer?

Yes, completely, and this is the most commonly overlooked consequence of the whole operation.

A PDF with real text can be searched, selected, copied, indexed by Google, and read aloud by a screen reader. A JPG of that same page is a picture of text. None of those things work any more — the words are now shapes.

That is sometimes exactly what you want. Converting to images is a crude but effective way to stop casual copy-and-paste, and it flattens any interactive form fields in the process.

But if you converted to JPG only to share a page and you still need the words back, you can recover them with OCR. The Image to Text tool reads the characters back out of the picture. It is good, not perfect — expect to proofread, especially around numbers, tables and unusual fonts.

Frequently asked questions