PDF to JPG: which resolution should you choose?

When you convert a PDF page to an image, the main decision is resolution. Too low and text is fuzzy; too high and each page becomes a huge file.

The pixel math

A4 is about 8.27 x 11.69 inches. At 150 dpi that gives roughly 1240 x 1754 pixels; at 300 dpi it is about 2480 x 3508. Doubling the dpi quadruples the pixels, and the file grows in a similar way.

Choosing a setting

Use 100 to 150 dpi for reading on screens or sharing in a chat. Use 150 for presentations. Use 300 only if you plan to print the image, and expect multi-megabyte files. PDF to JPG defaults to 150, a sensible starting point.

When JPG is the wrong format

JPG is designed for photographs. On sharp text and thin lines it leaves faint halos around edges. If the PDF is mostly text and you only need to send or archive it, keep the PDF. Convert to JPG when a website, form or messaging app specifically requires an image.

Multi-page files and memory

Each page becomes its own image, so a 40-page document gives 40 downloads. Rendering at high resolution takes memory, and older phones may fail on large pages. If it does, lower the dpi or split the PDF and convert it in parts.

Related: all guides and all tools.