The right PDF to image DPI depends on where the picture will end up. Use 72 DPI for small previews and thumbnails, 150 DPI for anything read on a screen, and 300 DPI for printing or for pages with very small text. These are the three settings in the PDFNova PDF to JPG tool, and picking the correct one saves you from both blurry images and needlessly heavy files.
What DPI means when a PDF becomes an image
DPI stands for dots per inch. When you turn a PDF page into a JPG or PNG, the converter has to decide how many pixels to use for each inch of the page. That number is the DPI.
A PDF page has a physical size, such as A4 or Letter. Multiply the page size in inches by the DPI and you get the pixel size of the image. So the same page becomes a small image at 72 DPI and a very large one at 300 DPI.
One detail surprises people: doubling the DPI does not double the number of pixels, it multiplies it by four, because both width and height grow. Going from 72 to 300 DPI gives roughly seventeen times as many pixels. That is why file size climbs so fast.
Pixel sizes at 72, 150 and 300 DPI
These figures come straight from the page dimensions, so they are the same in any converter that respects the page size.
| Setting | A4 page (pixels) | Letter page (pixels) | Best for |
|---|---|---|---|
| 72 DPI | about 595 x 842 | 612 x 792 | Thumbnails, previews, quick reference |
| 150 DPI | about 1240 x 1754 | 1275 x 1650 | Screens, slides, websites, messaging |
| 300 DPI | about 2480 x 3508 | 2550 x 3300 | Printing, zooming, fine detail |
Look at the 150 DPI row. An A4 page at that setting is already taller than most laptop screens and wider than most phone screens. This is why 150 is a sensible everyday choice.
When 72 DPI is enough
At 72 DPI a full page is small. Headings are readable, body text is readable at normal size, and footnotes start to break up. It works well when the image is only a visual hint of the document:
- a thumbnail in a product listing or a file index
- a preview picture in a chat so the other person knows which document you mean
- a placeholder in a draft layout
Do not use 72 DPI if someone has to read the page closely, and never use it for anything that will be printed. The result on paper looks rough.
When 150 DPI is the sensible middle
150 DPI is the setting to reach for when the image will be viewed on a phone, tablet or monitor. Normal body text is clear, tables are readable, and the file stays light enough to send or upload without trouble.
Good uses include a page dropped into a presentation, a certificate shared on social media, a page of notes sent to a study group, or a document image posted on a website. It is also a reasonable choice for home printing of simple pages when you are not worried about perfect sharpness.
When you really need 300 DPI
Choose 300 DPI when detail matters more than size:
- the image will be printed, or placed in a document that will be printed
- the page has small print, fine lines, engineering drawings, maps or dense tables
- you plan to crop a small area out of the page and enlarge it
- someone asked for a “high resolution” copy
If sharp text is the goal, combine 300 DPI with the PNG format. Our guide on how to convert PDF to PNG in high quality explains why PNG keeps edges cleaner than JPG.
How to set the PDF to image DPI in PDFNova
- Open PDF to JPG in your browser.
- Add the PDF you want to convert.
- Pick the format, JPG or PNG.
- Select 72, 150 or 300 DPI.
- Export a single page, or all pages at once.
- Save the image. If you exported every page, the images download as one ZIP file.
The conversion happens on your device. PDFNova processes files in your browser, so your documents are not uploaded to a server.
Common mistakes with DPI
Expecting a high DPI to repair a bad scan
DPI controls how finely the page is drawn, not how good the source is. If the PDF is a blurry phone photo of a page, exporting at 300 DPI gives you a large, blurry image. The fix is a better scan, not a higher setting.
Using 300 DPI for everything
A forty page report exported at 300 DPI can produce a ZIP that is slow to send and awkward to store. If the images are for screen reading, 150 DPI looks the same to most readers at a fraction of the size.
Converting a page when you only want a photo from it
A page export re-draws everything on the page at your chosen DPI. If your goal is one photograph or logo that sits inside the PDF, pull it out directly with Extract Images. Read how to extract images from a PDF in original quality for the details.
Turning a page into an image when you need the words
An image of a page cannot be edited or searched. If you need to change the text, converting to a document is the better route. See how to convert PDF to Word for free, and for an honest look at what survives the conversion, PDF to Word without losing formatting.
A quick way to decide
- Will it be printed? Use 300.
- Will people zoom in or read small print? Use 300.
- Is it for a screen, a slide or a message? Use 150.
- Is it only a preview? Use 72.
- Still unsure? Export one page at 150 and check the smallest text at the size it will be shown.
Frequently asked questions
Is 150 DPI good enough for printing?
It is acceptable for simple pages with normal sized text on a home printer. For small text, photos or anything you hand to a print shop, 300 DPI is the safer choice.
Does a higher DPI make the file bigger?
Yes, and quickly. The pixel count grows with the square of the DPI, so a 300 DPI image has four times the pixels of a 150 DPI one. The exact file size also depends on the format and on what is on the page.
What DPI should I use to post a PDF page online?
150 DPI is a good default. Many sites resize large pictures anyway, so a very high resolution upload brings little benefit. If a site has an upload limit, check the limit shown on the upload page.
Can I change the DPI of an image after converting?
You can shrink an image later, but enlarging it does not bring back detail. If you need more resolution, go back to the PDF and export again at a higher setting.
Choose the DPI for the destination, not out of habit: 72 to preview, 150 to view, 300 to print. When you are ready, open the PDF to JPG converter and export a test page to see the difference for yourself.