How to get high-resolution images out of a PDF
By the PdfDady team · Updated · 7 min read
For a sharp image of a whole PDF page, convert it to PNG at 300 DPI. An A4 page comes out at about 2,480 × 3,508 pixels, which is enough to print at full size or zoom into small text. You can do that with our PDF to PNG tool, in the browser, without uploading the file.
There is a catch worth knowing before you start. 300 DPI gives you more pixels. It does not always give you more detail. If the page is a low-quality scan, no setting will sharpen it, and if what you want is a photo that sits inside the PDF, pulling out the original is often better than converting the page. Both cases are covered below.
What "high resolution" means here
A PDF page has a physical size, such as A4. DPI (dots per inch) is how many pixels you ask for per inch of that page. Multiply and you get the image size:
| Page | 150 DPI | 300 DPI |
|---|---|---|
| A4 (210 × 297 mm) | About 1,240 × 1,754 px | About 2,480 × 3,508 px |
| A5 (148 × 210 mm) | About 874 × 1,240 px | About 1,748 × 2,480 px |
| ID card (85.6 × 54 mm) | About 506 × 319 px | About 1,011 × 638 px |
The rule runs backwards too. An image printed at 300 DPI covers one inch for every 300 pixels. So a 2,480 pixel wide image prints about 8.3 inches wide, which is the width of A4. 300 DPI is the usual benchmark for print that looks clean at reading distance, and 150 DPI is fine for screens.
Notice the last row. A card-sized page at 300 DPI is only about a thousand pixels wide. A small page gives a small image, however good it is.
How to convert a page at 300 DPI
- Open PDF to PNG and add your PDF (one file, up to 100 MB). If it is password-protected, enter the password. It is used only in your browser to open the file.
- Convert all pages, or tap Select and choose the ones you need.
- Pick 300 DPI.
- Press Convert. One page downloads as a PNG. Several come together in a ZIP.
PNG is the right format for this job because it is lossless: it doesn't blur text or lines the way JPG compression can. The price is file size. A 300 DPI PNG of a page with photos can run to several MB. If you need a smaller file and can accept a little softness, switch the format to JPG. Our guide on choosing JPG or PNG compares the two.
Pages are drawn on a white background, the way they look in a PDF viewer. You won't get transparency.
Why some pages stay blurry at 300 DPI
What happens at 300 DPI depends on what the page is made of.
Real text and vector drawings get sharper. Text typed in Word, or a chart drawn by software, is stored in the PDF as shapes and letters, not pixels. These can be drawn cleanly at any size, so 300 DPI gives you crisp edges. This is the case where a high DPI pays off fully.
Scans and photos do not. A scanned page is a picture with a fixed number of pixels, set when it was scanned. If that scan is about 1,240 pixels wide on an A4 page, it holds 150 DPI worth of detail. Converting at 300 DPI stretches those pixels over a bigger image. The file is larger and the page is no sharper.
A quick way to tell which you have: open the PDF and zoom in to 400%. If the letters stay smooth, it is real text. If they turn blocky or fuzzy, it is a scan, and the fuzziness you see is all the detail there is.
For a scan, the only way to get more detail is to go back to the source: rescan the paper at a higher setting, or download a fresh digital copy if one exists. Many documents do exist digitally, such as a DigiLocker document or a statement from your bank's site. That copy will beat any scan of a printout.
When extracting the original image is better
Say a PDF brochure contains a product photo, or a report contains a team picture, and you want that picture alone. Converting the page gives you the whole page, text and margins included, with the photo resampled to whatever DPI you chose. You would then have to crop it.
Extract images from PDF takes the other route. It finds the images stored inside the file and saves them as they are:
- Photos stored as JPEG are copied byte for byte. You get the exact image that is in the PDF.
- Other images are saved as lossless PNG at their stored resolution, with transparency where the PDF has it.
- Everything comes in one ZIP,
pdf-images.zip.
That can beat a 300 DPI page render in two ways. The photo may be stored at a higher resolution than 300 DPI gives you at its size on the page. And nothing is re-compressed, so no quality is lost in the process.
It can also be worse. If the photo was shrunk when the PDF was made, the stored original is small, and that is all there is. Extraction never invents pixels either.
| You want | Use | Why |
|---|---|---|
| A whole page as a picture | PDF to PNG at 300 DPI | Renders text, drawings and photos together |
| A sharp image of a chart or diagram | PDF to PNG at 300 DPI | Charts are usually drawn, not stored as images |
| A photo or logo that sits inside the PDF | Extract images | Gets the stored original, no resampling |
| Pages of a scanned PDF | Either | Each scanned page is usually one image; extraction gives it at its stored size |
A few limits to know. Text, charts and drawings are usually not images, so extraction won't find them. A few rare image types, such as CMYK, are skipped and counted. And a password-protected PDF has to be unlocked first, which you can do with Unlock PDF if you know the password.
Limits on very large pages
The converter offers 72, 150 and 300 DPI. It does not go above 300.
Very large pages are also reduced to stay within what browsers can handle. A4 at 300 DPI is fine. A poster-sized page, or an engineering drawing on a large sheet, may come out at less than the DPI you chose. If you need a huge image from a large-format PDF, a desktop program built for print work is the better tool for that job.
Tips for printing
Match the DPI to the print size, not the other way round. If you will print the image at the same size as the PDF page, 300 DPI is plenty. If you plan to enlarge it, say an A4 page blown up to A3, the effective resolution drops to about 212 DPI. That is still acceptable for a notice on a wall, less so for fine print read up close.
If the goal is just to print the page, print the PDF. A PDF with real text prints at the printer's full resolution. Converting to an image first can only match that, never improve on it. Convert when the destination needs an image: a slide, a design app, a website, a print shop's photo kiosk.
Check the image at 100% before you send it to print. Open it and look at the smallest text. If it reads cleanly on screen at full size, it will print cleanly.
Questions people ask
Can I get more than 300 DPI?
Not with our tool. 300 DPI is the highest setting. For real text and vector pages, a desktop PDF program can render higher. For scans, a higher number would not add detail anyway.
Why is my 300 DPI PNG so large?
Four times the pixels of 150 DPI, stored without loss. Use JPG, or 150 DPI, if the size is a problem.
Does converting to PNG improve a blurry PDF?
No. Converting can keep the quality that is in the file. It can't add what was never captured.
Will the extracted photos be the same quality as the originals?
They are the same as what is stored in the PDF. JPEG photos are copied exactly. Whether that matches the photo the author started with depends on how the PDF was made.
Are my files uploaded?
No. Both tools work in your browser and the PDF stays on your device.