ToolSahla, Tools Sahla

How to convert PDF pages to images

You want to post a catalog page on Instagram, or send one page of a quotation on WhatsApp as a picture that opens instantly. The answer is to turn the page into a real image at the resolution that suits where it will go.

Published · 2 min read

What is DPI and why does it matter?

A PDF page is measured in points, and one inch is 72 points. DPI is the number of pixels per inch in the output image. The higher you set it, the bigger, sharper and heavier the image. 150 is usually enough for screens, and 300 for print.

Worked example

A 400 × 300 point page at 150 DPI gives an 834 × 625 pixel image, because every 72 points become 150 pixels.

The same page at 72 DPI gives 400 × 300 pixels.

An A4 page of 595 × 842 points gives 1240 × 1755 pixels at 150, and 2480 × 3509 pixels at 300.

How to do it

  1. Open the PDF to images tool and choose a PDF.
  2. Pick the image format, PNG or JPEG, and the quality if you chose JPEG.
  3. Pick the resolution: 72, 96, 150, 200 or 300 DPI, or a zoom factor.
  4. Set a page range if you need one, and check the pixel sizes shown before converting.
  5. Press “Convert”, then download each image on its own or all of them in a ZIP.

PNG or JPEG?

  • PNG: lossless, and best for pages with text, tables and sharp lines. The files are larger.
  • JPEG: smaller, and good for pages full of photos. It has no transparency, so pages are drawn on a white background.

If the images come out too heavy to post, shrink them after converting with the Image compressor.

Limits to know

  • Tested limits: a file up to 100 MB and 500 pages, and up to 100 pages per conversion. Resolution from 36 to 600 DPI.
  • The largest image the browser can draw is 8000 pixels per side and 25 million pixels per page. A page above that is refused with its number and size before starting, so you never get a half-finished set.
  • The output is a picture of the page, not text, so you cannot select or search the words. To get the words out, use the PDF text extractor.
  • Password-protected or encrypted files are refused.

Common questions

What resolution is best for Instagram or WhatsApp?

150 DPI is usually enough for an A4 page on screen, giving an image 1240 pixels wide. Go higher if the page has small text.

Is my file uploaded?

No, the pages are drawn inside your browser.

Why does the font look slightly different?

If the font is not embedded in the file, it is replaced with the closest one available, so it can look slightly different from another viewer.