Check PDF image DPI
What Check PDF image DPI actually does
A 300-PPI image can become a 150-PPI image when it is enlarged to twice its intended size. This preflight reads each PDF image's native pixel dimensions and placement transform, then reports the effective resolution on both axes at the size it will actually print. One-bit stencil artwork is measured too, against the higher limit that line art needs.
How to use it
- Set two minimums: one for color and grayscale images and a higher one for bilevel line art.
- Inspect every raster placement by page, image kind, native pixels, placed size, axis resolution, the limit applied, and pass or low status.
- Download the complete preflight as CSV for a print job or JSON for another workflow.
Useful for
- Catch blurry photographs before a brochure, worksheet, or book goes to print.
- Locate the page where an image was enlarged beyond its useful resolution.
- Add a deterministic low-resolution gate to a print-production handoff.
Limits worth knowing
- Bilevel line art and bitonal scans are measured against their own higher limit, because a one-bit image has no halftone to hide missing detail.
- Vector artwork and text are resolution-independent and are not listed as raster images.
- Resolution is one print-quality factor; bleed, color space, fonts, transparency, and compression need separate checks.
- The report measures source pixels at placement size and cannot restore missing detail.
Questions people ask
Is this DPI or PPI?
For a raster image, pixels per inch is the precise term. The phrase image DPI is commonly used in PDF and print searches, so the interface shows effective PPI while supporting that familiar name.
What threshold should be used?
300 PPI is a common target for close-view quality print, 150 PPI can suit everyday print, and lower values may be acceptable for screen use or large-format work viewed from farther away. Bilevel line art is normally prepared far higher, between 600 and 1200 PPI, and carries its own field.
Are one-bit stencil images included?
Yes. A logo or a bitonal scan stored as a stencil mask is measured like any other placement and is judged against the bilevel minimum rather than the color one.
Does the PDF leave the browser?
No. The PDF operator list and image placement transforms are inspected locally; the site has no upload endpoint.