Convert PDF to images

What converting a PDF to images is for

Turning PDF pages into images is handy to drop them into a presentation or a document, share them on social media and chats where the PDF has no preview, or crop and edit a single page in a photo editor.

JPG or PNG?

Choose JPG for lighter files, perfect for photos and image-heavy pages. Choose PNG for maximum sharpness on text and graphics, ideal if you'll enlarge or print them.

Resolution is the choice that decides everything

A PDF has no pixels: it contains text and vectors, and the images are generated on the spot. The number to choose is dots per inch, and it changes everything: at 72 DPI an A4 page becomes an image of about 595 by 842 pixels, fine for a screen; at 150 it doubles; at 300, which is print resolution, you reach about 2480 by 3508 pixels and several megabytes per page.

The practical rule is 150 DPI to look at, 300 to print. Going further adds no detail if the original PDF was made of text, and only produces enormous files. Anyone left with a grainy image after conversion has almost always chosen 72.

JPG or PNG, and why the wrong choice shows at once

The PNG is the right format when the page is made of text, tables and line art: it keeps the edges sharp and often weighs less too. JPG is the right format when the page is almost entirely photographs, where it produces far lighter files and the loss goes unnoticed.

The mistake seen every time is a text page saved as JPG at medium quality: a dirty halo appears around the letters, and the text becomes tiring to read on screen. It is the same flaw as screenshots saved as JPG, and it comes from that format working badly precisely on sharp contrasts.

What is lost by becoming an image

Everything that made the PDF useful: the text is no longer selectable or searchable, the links stop working, the forms cannot be filled, and anyone using a screen reader can no longer read a thing. A page of text turned into an image is, for a search engine and for an accessibility tool, a mute surface.

That is why it is worth asking why the image is needed. To put a page into a presentation or a message, it is the right choice. To share a document someone will have to read or quote, hardly ever: there the PDF stays better, and if anything the text is extracted.

Size, and PDFs that are already images

Conversion easily produces big files: a forty-page document at 300 DPI passes a hundred megabytes without effort. If they are for a screen, it is better to drop to 150 and use JPG; if only a few pages are needed, it is better to extract only those.

Then there is the opposite case: a PDF that is already a scan, that is a container of photographs of pages. There raising the DPI achieves nothing, because detail that is not present cannot be invented: all you get is a heavier file. If such a document needs to be readable and searchable, the right step is not converting it into images but putting it through text recognition.

Nearby tools

For the opposite direction there is Image to PDF, and for text Extract text from a PDF or Image to text for scans. On the resulting images work Compress image and Resize photo.