Browser-only print PDF preflight
Free book image DPI checker
Book image DPI checker for the size you will actually print.
A 3,000-pixel image may be sharp at four inches and soft at twelve. Check the effective resolution at its intended width and height before placing it in the interior.
✓Local browser inspection✓Effective DPI at final size✓Aspect-ratio warning
Check an image at its intended print size
Choose a JPEG, PNG, or WebP. The browser reads only its pixel dimensions; the image is not uploaded.
Pixel dimensions only become meaningful at print size
Effective DPI is the source pixel count divided by the inches it occupies on the page. The checker uses the lower horizontal or vertical result because that is the limiting direction.
A result of 300 DPI or more is a useful early signal for many print workflows, not an approval guarantee. Line art, fine maps, screenshots, and heavily compressed photos may need a different judgment even at the same number.
What this browser check cannot prove
The tool does not inspect embedded ICC profiles, ink coverage, transparency flattening, bleed, source rights, or whether the image is aesthetically sharp. It also does not upscale or alter the selected file.
Use the printer or distributor's own preflight for the final production decision. If the source and destination proportions differ, plan a crop or padding instead of stretching the image.
FAQ
Frequently asked questions
What DPI should a book image be?
300 DPI at final placement size is a common target for continuous-tone print images. Requirements vary by printer, material, and image type, so confirm the current production specification.
Does changing the DPI metadata add detail?
No. Changing a DPI label without adding real pixels does not create detail. Effective DPI depends on source pixels and the size at which those pixels are printed.
Is my image uploaded?
No. This tool reads pixel dimensions in the browser and sends only non-content funnel metrics, never the image or its filename.
Image DPI is one part of print preflight.
Check the complete interior PDF for page size, encryption, fonts, and other early production signals.