Question 1

Which resolution should I choose?

Accepted Answer

It depends on where the image goes. 72 DPI matches the page at 100% zoom and suits small previews. 150 DPI is sharp on a phone or laptop and keeps files small enough to email. 300 DPI is the usual figure for printing and for OCR software, which reads text more reliably at that density. 600 DPI is for fine print and technical drawings, and the files are about four times the size of 300.

Question 2

JPG or PNG?

Accepted Answer

JPG for scanned pages and anything with photos, because it makes files several times smaller. PNG for pages of plain text, charts and line drawings, where JPG compression can leave faint smudges around sharp letter edges. PNG is lossless, so its files are larger, especially at 300 DPI and above.

Question 3

Why is the image the size I chose when I put it into Word?

Accepted Answer

Each image carries its resolution inside the file, in the JFIF header of a JPG or the pHYs chunk of a PNG. Word, LibreOffice and print dialogs read that value, so a page converted at 300 DPI goes in at the size of the original A4 or Letter page. Images saved without it are usually treated as 96 or 72 DPI, which makes a 300 DPI page arrive three or four times too large.

Question 4

Can I convert a password-protected PDF?

Accepted Answer

Yes. Some PDFs only restrict printing, copying or editing, and those open straight away without a password. A PDF that needs a password to open shows a box for it. Type the password you were given and its pages load as usual.

Question 5

Why do some pages come out below the DPI I picked?

Accepted Answer

Browsers limit how large a single image they can draw. Safari, and every browser on an iPhone or iPad, stops at about 16.7 million pixels, which an A4 page passes somewhere above 400 DPI. Other browsers allow far more, but very large pages still hit a limit. When that happens the tool says so before you convert, lowers the resolution for those pages only, and writes the resolution they actually got into the files.

Question 6

Can I edit or copy the text in the images?

Accepted Answer

No. The images are pictures of the pages, so the text is pixels rather than characters. To get editable text from them, run the images through OCR software, ideally at 300 DPI. If the PDF itself has selectable text, copying it from the PDF is quicker and exact.

Question 7

Are form fields and comments included?

Accepted Answer

Yes, as far as they are visible on the page. Text typed into form fields, ticked boxes, highlights and stamps are drawn into the image. Pop-up notes that only open when clicked are not, since they are not part of what the page shows.

Question 8

How are the images named?

Accepted Answer

After the PDF, followed by the page number padded with zeros: report_page-01.jpg up to report_page-12.jpg for a twelve-page file. The padding keeps the images in page order in any folder. The ZIP takes the PDF's name too, as report_jpg.zip or report_png.zip.

Question 9

Is there a page or size limit?

Accepted Answer

The PDF can be up to 100 MB, with any number of pages. Each page is drawn and saved one after another, and the button counts them as it goes. Converting hundreds of pages at 300 DPI or more takes a while and a good deal of memory, so on a phone it is quicker to convert a long document in parts.

PDF to JPG

About PDF to JPG

How to use PDF to JPG

Frequently Asked Questions