Print production · PDF preflight
Know your page boxes.
Read a PDF’s MediaBox, CropBox, TrimBox, and BleedBox page by page. The file stays in this browser; no upload or remote conversion is involved.
Choose a PDF
Preflight report
Choose a local PDF to inspect its page boxes.
What the boxes mean
MediaBox is required and defines the physical page extent. CropBox controls the displayed or printed region when present. TrimBox describes the finished size after trimming, while BleedBox describes the professional-print clipping area. If a PDF omits CropBox, TrimBox, or BleedBox, this checker reports the omission instead of silently presenting a fallback as if the box had been authored.
Limitations: the report reads page dictionaries and does not inspect artwork, bleed objects, fonts, colour profiles, PDF/X conformance, overprint, marks, or printer imposition. A missing box is not automatically a failed file; follow the receiving printer or platform’s specification.
Box definitions checked 29 September 2026 against Adobe’s PDF reference. PDF parsing is local and uses the locked pdf-lib 1.17.1 package.