Book & Print Tools › Image DPI checker

DPI, dots per inch, tells you how much detail an image has once it is printed at a certain size. A photo that looks sharp on a screen can look blurry in print if it has too few pixels for the size you give it.

Choose an image file and the width you plan to print it at. The tool reads the pixel width in your browser and divides it by the print width. The file never leaves your device. You can also type the pixel width yourself if you do not have the file.

For books, 300 DPI is the usual target. Between 240 and 300 is acceptable for most images; below that, print will look soft. If the result is low, use a larger original, or print the image smaller. Do not just enlarge a small file, since that adds pixels but no detail.

How to use it

1. Choose an image, or type its pixel width.
2. Enter the width it will have on the page.
3. Check the verdict, and resize or replace the image if it is too low.

Worked example

1800 px printed 6 in wide is exactly 300 DPI.

Sources and figures

• DPI thresholds are listed in figures.json under 'dpi'.

Questions

Does the image get uploaded?

No. It is read in your browser and stays on your device.

Is 150 DPI ever fine?

For large posters viewed from a distance, yes. For book pages, no.

What about the DPI value saved in the file?

It is only a hint. What matters is pixels divided by printed size.

Can I fix a low-DPI image?

Use a higher resolution original. Upscaling does not add real detail.

Files you choose here are processed in your browser and are not uploaded.

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