Cropping a PDF page removes unwanted content from the edges — excessive white margins, headers or footers you don't need, or content outside the area you want to keep. The result is a smaller page canvas showing only the portion you selected. It's one of the most common page-level edits, and several tools handle it without requiring Acrobat Pro.
What Cropping Actually Does in a PDF
PDF cropping works by adjusting the page's CropBox — a boundary that defines what portion of the page is visible. Content outside the CropBox is hidden but not deleted from the file. This is an important distinction: a cropped PDF is not smaller in terms of data — the full original content still exists in the file, just outside the visible area.
This means cropping is reversible — you can uncrop a PDF by resetting the CropBox to the full page dimensions, and the hidden content reappears. It also means that sharing a cropped PDF for confidentiality reasons is not secure: the cropped content is still accessible to anyone who resets the crop boundaries. For truly removing content permanently, use redaction rather than cropping.
Cropping in Adobe Acrobat Pro
Acrobat Pro offers the most precise cropping control. Go to Tools > Edit PDF > Crop Pages. You can draw a crop rectangle directly on the page, or use the Set Page Boxes dialog to enter exact measurements for each margin. The dialog lets you set margins in millimeters or inches, apply to all pages or a specific range, and preview before applying. For cropping all pages identically — removing the same margin from every page of a scanned document — applying to all pages at once is much faster than cropping individually.
After cropping, save the file. The crop takes effect immediately in the saved version. If you need to undo the crop later, use the same Crop Pages tool and reset the CropBox to the original MediaBox dimensions.
Cropping on Mac With Apple Preview
Preview on Mac handles cropping cleanly without additional software. Open the PDF in Preview, show the Markup toolbar (View > Show Markup Toolbar), draw a selection rectangle over the area you want to keep, then go to Tools > Crop (or press Cmd+K). Save the file and the page is cropped to your selection. Preview crops one page at a time — for multi-page PDFs where every page needs the same crop, use a tool that supports batch cropping or repeat for each page.
Using a Browser-Based PDF Editor
Browser-based PDF Editor tools offer cropping without requiring any software installation. Upload the PDF, use the crop tool to draw the desired area, apply, and download. This works on any device including mobile and is practical for one-off cropping tasks.
For frequent or batch cropping needs, a desktop tool with precise measurement input — Acrobat Pro or PDF-XChange Editor — provides more control and consistent results across pages.
Common Cropping Use Cases
- Removing scan borders: scanned documents often have black borders or shadow edges from the scanner glass — cropping removes these consistently across all pages
- Extracting a specific area: isolating a chart, diagram, or figure from a larger page to use as a standalone element — crop to the area, then use a PDF to Image tool to export the cropped page as an image
- Reducing margins for mobile reading: documents with very wide margins waste screen space on mobile — cropping tightens the layout for a better reading experience on small screens
Cropping vs Permanently Removing Content
Cropping hides content rather than deleting it. If the goal is to permanently remove content from the file — for confidentiality, compliance, or actual PDF File Size reduction — use a dedicated redaction tool instead. Redaction removes the content data from the file entirely, whereas cropping only adjusts the visible boundary while leaving the original data intact behind the scenes.