How does it know a file is scanned?

It checks whether pages have a text layer. Scans are images, so they have none until OCR is run.

Why do mixed page sizes matter?

They make printing unpredictable. Normalize Page Sizes fixes it.

Is anything sent anywhere?

No. The whole inspection runs in your browser.

inspect

Inspect a PDF

See what a PDF actually contains before you work on it.

Runs in your browser

How it works

A single report covering page count and sizes, mixed sizes and orientations, whether pages carry a selectable text layer or are scans, bookmarks, form fields, annotations, PDF version and document properties. This is the tool to run first when a document is behaving strangely.

Related tools

Detect Blank Pages

/detect-blank-pdf-pages

Find Duplicate Pages

/find-duplicate-pdf-pages

Questions

How does it know a file is scanned?: It checks whether pages have a text layer. Scans are images, so they have none until OCR is run.
Why do mixed page sizes matter?: They make printing unpredictable. Normalize Page Sizes fixes it.
Is anything sent anywhere?: No. The whole inspection runs in your browser.