Book & Print Tools › Print preflight (basic)

Preflight means checking a file against what a printer needs before you send it. A basic check catches the common mistakes: the wrong page size, missing bleed, fonts that are not embedded and images with too few pixels.

Choose your PDF and pick the trim size you expect. The tool compares the first page with that size, looks for a bleed box, lists whether each font is embedded, and warns about images whose resolution is low at the size they are placed. It reads the file in your browser and uploads nothing.

This is a basic check, not a certified one. It does not test colour spaces, transparency or PDF/X conformance, and some printers require those. Treat a pass as a good sign and confirm the printer's own requirements.

How to use it

1. Choose your PDF.
2. Pick the trim size you ordered.
3. Fix the items marked as problems and check again.

Worked example

Reports page size, bleed and embedded fonts, with a pass or a warning on each line.

Sources and figures

• pdf.js, Apache License 2.0.

Questions

Is this PDF/X validation?

No. It is a basic check and does not certify PDF/X.

What bleed does it expect?

A page larger than the trim by about 3 mm on each side, with a BleedBox if the file has one.

Is the file uploaded?

No. It is read in your browser.

What does the image check use?

The pixel size of each image and the size it is placed at in the PDF.

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

Turn your Markdown into a book

Related tools