Converting PDF to JPG or PNG: Getting the Resolution Right
Exporting a PDF page as an image looks like a one-click job, and it is — except for a single setting that decides whether you end up with something blurry, something enormous, or something correct.
How to extract high-resolution images from a PDF
To pull a high-resolution image out of a PDF, set the export DPI before you convert, not after. A PDF page stores drawing instructions, not pixels, so the resolution is created at the moment you rasterise it. Multiply the page size in inches by your chosen DPI to get the pixel dimensions: an A4 page is 8.27 × 11.69 in, so 300 DPI produces 2481 × 3508 px. Use 96–150 DPI for screen use, 300 DPI for print, and 400–600 DPI only for OCR or heavy enlargement. Choose PNG for text, line art and diagrams because it is lossless, and JPG only for photographic pages. Upscaling afterwards cannot recover detail that was never rendered — a blurry export almost always means the DPI was set too low at conversion time.
A PDF page has no pixels
This is the part that catches people out. A photograph has a fixed pixel count baked in. A PDF page does not.
A PDF describes its page in abstract units — draw this glyph outline at this coordinate, at this size. Those descriptions are resolution-independent, which is why you can zoom to 800% in a PDF viewer and the text stays perfectly sharp.
When you convert to JPG or PNG, that resolution independence ends. The converter must render the page into a grid of pixels, and you decide how fine that grid is. That choice is the entire quality question.
Working out the actual pixel size
PDF pages are measured in points, at 72 points per inch. A4 is 595 × 842 points; US Letter is 612 × 792.
Rendered pixel dimensions are simply the page size in inches multiplied by your chosen DPI. For A4 (8.27 × 11.69 inches):
- 72 DPI → 595 × 842 px — soft on any modern screen
- 150 DPI → 1240 × 1754 px — comfortable for web and presentations
- 300 DPI → 2480 × 3508 px — print standard
- 600 DPI → 4960 × 7016 px — OCR and large-format enlargement
Notice the growth. Doubling DPI quadruples the pixel count, because it doubles in both directions. Going from 150 to 600 DPI multiplies the data by sixteen. This is why "just use maximum quality" produces files nobody can email.
Choosing a DPI
96–150 DPI for anything viewed on a screen — web pages, slides, documentation, an image pasted into a chat. 150 gives some headroom for high-density displays without much cost.
300 DPI for print. This is the long-standing commercial printing standard and there is rarely a reason to exceed it for normal output.
400–600 DPI only for OCR or genuine enlargement. Character recognition benefits from extra detail because it is analysing letterform shapes rather than showing them to a human eye.
The mistake in both directions is common. People export at 72 because it is the default and wonder why it looks soft, or export at 600 for a web thumbnail and produce a 30 MB PNG.
JPG or PNG
They fail in opposite ways, and the page content decides which is right.
PNG is lossless. Every pixel is reproduced exactly. Its compression works well on large areas of flat colour and hard edges — which describes text, diagrams, charts and line art precisely. Choose PNG for anything document-like.
JPG is lossy, and its compression is tuned for photographs, where gradual tonal variation hides the artefacts. On a photo-heavy page it produces dramatically smaller files at indistinguishable quality.
The visible failure is putting text through JPG at a low quality setting. JPG works in 8×8 pixel blocks, and sharp black-on-white edges produce ringing — a faint halo of grey speckle around every letter. Once you know to look for it you will see it on badly exported documents everywhere.
A page with both text and photos is a genuine trade-off. PNG at moderate DPI is usually the safer default, since crisp text matters more to most readers than a slightly larger file.
What you lose by rasterising
Converting a page to an image discards everything that made it a document:
- Text becomes pixels. Not selectable, not searchable, not extractable. Recovering it needs OCR.
- Links stop working. A hyperlink is an annotation object, and images do not have those.
- Accessibility is gone. A screen reader can read a tagged PDF; it cannot read a picture of one.
- Resolution is fixed forever. Zooming past your chosen DPI shows pixels.
That last one deserves emphasis. Render at 72 DPI, discard the PDF, and there is no way back — the detail was never captured. Always keep the source PDF.
When rasterising is the right call
Despite all that, it is often exactly what you want:
- Embedding a page into a slide deck, a design file or a web page
- Producing a thumbnail or preview
- Sharing a single page somewhere that only accepts images
- Guaranteeing a page renders identically everywhere, with no font substitution
- Deliberately making text non-extractable for a visual asset
Our PDF Tools convert PDF pages to images in your browser, with no upload. As with the rest of the toolkit that locality matters most for the documents you would least like to send to a server.
Quick reference
- Screen use: 150 DPI, PNG for text, JPG for photos.
- Print: 300 DPI.
- OCR: 400–600 DPI.
- Doubling DPI quadruples file size.
- Never put fine text through low-quality JPG.
- Keep the original PDF — rasterising is one-way.
Try it yourself
Our free PDF to image converter needs no account and adds no watermark — use it right now, as many times as you like.
Open PDF Tools →Frequently Asked Questions
What DPI should I use when converting a PDF to an image?
Around 96 to 150 DPI for on-screen use such as web pages and slides, 300 DPI for print, and 400 to 600 DPI only when the output will feed optical character recognition or needs enlargement. Higher is not automatically better — it multiplies file size quadratically while adding nothing visible on screen.
Should I use JPG or PNG?
PNG for pages that are mostly text, line art or diagrams, because it is lossless and keeps edges crisp. JPG for pages dominated by photographs, where its compression is far more efficient and the artefacts are hard to see. A text page saved as a low-quality JPG shows visible fringing around the letters.
Why is my converted image blurry?
Almost always because the export resolution was too low. A PDF page is described in vector terms and has no native pixel dimensions, so the converter renders it at whatever DPI you specify. At 72 DPI an A4 page becomes roughly 595 by 842 pixels, which looks soft on any modern display.
Does converting a PDF page to an image make the text unselectable?
Yes, and that is often the point. Rasterising turns text into pixels, so it can no longer be selected, searched or extracted — useful for embedding a page in a design, and a drawback if anyone later needs the text, since recovering it would require OCR.
What pixel size will my PDF page become?
Page width in inches multiplied by DPI gives pixel width. A4 (8.27 by 11.69 in) gives 794 by 1123 px at 96 DPI, 2481 by 3508 px at 300 DPI, and 4961 by 7016 px at 600 DPI. US Letter (8.5 by 11 in) gives 2550 by 3300 px at 300 DPI. If your PDF reports page size in millimetres, divide by 25.4 first.
How do I export a PDF page as a high-DPI PNG?
Set the DPI at export time to 300 or above and choose PNG rather than JPG. PNG is lossless, so text edges and thin lines stay crisp instead of picking up the soft halo that JPG compression leaves around high-contrast detail. The trade is file size: a 300 DPI A4 PNG is typically several times larger than the same page saved as JPG.
Can I increase the resolution of an image already exported from a PDF?
Not meaningfully. Resizing a 96 DPI export up to 300 DPI stretches the pixels you already have; it invents no new detail and usually looks worse than the original. Go back to the PDF and re-export at the higher DPI, which costs nothing because the source is still vector.