How it works
- 01Open the PDF.
- 02Wait a moment while the pages are measured.
- 03Set how much breathing room to keep around the content.
- 04Export.
Measured, not guessed
The crop comes from the objects actually on each page — the text, the images, the lines — rather than from analysing pixels for whiteness. That means it is exact rather than approximate, it costs nothing to compute, and it cannot be confused by a page whose background is not quite white.
Each page gets its own crop
The manual Crop tool applies the same margins to every page, which is right when you are removing a header band. Auto-crop treats each page separately, which is right when a scanner fed the pages unevenly.
Pages it cannot measure are left alone
A blank page has no content to measure against, so it is passed through untouched rather than cropped to nothing. The panel tells you how many pages it could and could not measure, because a silent skip would look identical to a silent failure.
Cropping hides, it does not delete
The trimmed margins are still in the file and can be recovered by removing the crop. If something in the margin is sensitive, cropping is not the tool — redaction is.
Questions
- What if it crops too tightly?
- Increase the padding. It defaults to keeping twelve points of space around the content, which reads as a normal margin rather than a tight box.
- Will it deskew a crooked scan?
- No. Auto-crop squares up the margins but does not rotate the content. Straightening a crooked scan is the Clean up a scan tool, which measures the skew and rotates the page.
- Does it make the file smaller?
- Barely — the content is still there. Use Compress for that.