What is Crop PDF?
Crop PDF changes the CropBox on every page by trimming the same percentage from the left, right, top, and bottom. The interface supports 0% through 25% in one-percent steps.
Cropping changes the visible page region; it does not erase content outside that region. Hidden material may remain in the PDF and can potentially be restored or inspected with other software.
Why Use This Tool?
Uniform cropping is useful for removing consistent scan borders or excess whitespace across a document before viewing or printing.
- Trim equal margins on all sides
- Apply one setting to every page
- Reduce visible scan borders
- Keep page content in its original PDF structure
How Does This Tool Work?
For each page, the selected ratio is multiplied by the page width and height. The new CropBox begins at those offsets and spans the remaining central area.
Pages with different sizes are cropped proportionally, so the absolute amount removed can differ from page to page.
Understanding Your Results
The output viewer should show a smaller visible area. Because the content stream is unchanged, crop is a presentation operation and must not be used to conceal confidential information.
Why Tracking This Matters
A consistent visible frame can improve readability, but aggressive cropping may hide headers, annotations, page numbers, or printer marks.
Benefits of Using Crop PDF
- Uniform proportional crop
- Applies to every page
- Supports mixed page sizes proportionally
- Does not rasterize pages
- Runs locally
- Creates a separate output file
How Is the Result Calculated?
At margin ratio r, each dimension loses twice the corresponding margin.
New width = width × (1 − 2r); new height = height × (1 − 2r)
- r
- Selected margin percentage divided by 100.
- Width and height
- The original dimensions of each page.
Tips for Better Results
- Start with a small percentage.
- Check pages with the tightest content.
- Remember that mixed page sizes lose different absolute margins.
- Do not use crop for redaction.
- Keep the original in case content is hidden.
Conclusion
Crop PDF proportionally trims the visible margins of every page without rasterizing it. Use conservative settings, inspect every page type, and never treat cropping as secure deletion.