Crop PDF Pages Online – Trim Margins and Resize Page Bounds
1. Choose a PDF
2. Set crop margins
Enter non-negative margins. At least 6.4 mm (18 pt) of page width and height must remain.
3. Optional: detect content
Find near-white borders separately on each selected page. Faint edge marks, paper shadows, and coloured backgrounds need manual review.
4. Review and download
Choose a PDF or use the example, then drag the blue crop handles or enter exact margins.
The dark area will be outside the new page bounds. Drag the crop rectangle, use its eight handles, or focus it and press an arrow key to move it (Shift + arrow moves farther).
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How to crop PDF pages online
What the PDF cropper changes
A PDF page can define several rectangular page boxes. This tool sets the exported MediaBox, CropBox, TrimBox, BleedBox, and ArtBox to the selected visible rectangle. That resizes the page boundary without intentionally rasterizing the original text and graphics. The page content is not scaled or stretched; content outside the new bounds is simply no longer part of the visible page area.
Exact margins are measured in the page’s displayed orientation. PDF measurements use points: 72 pt = 1 in = 25.4 mm. When you apply margins across mixed page sizes, the same physical amount is removed from each selected page. Automatic detection instead finds a separate content rectangle for every page.
When automatic trimming needs review
Content detection renders a temporary page image and looks for pixels darker or more colourful than near-white. It works well for clean documents with white paper margins. Faint pencil marks, scanner shadows, punched holes, crop marks, coloured paper, transparent artwork, and content touching the edge can make the detected boundary too large or too small. Padding is added after detection; inspect every affected page before download.
Document warning: modifying page boxes can invalidate an existing certificate-based digital signature. Some printing, prepress, archival, form, annotation, and accessibility workflows depend on page boxes or viewer-specific behavior. Open the result in the recipient’s expected viewer and verify it before sharing or submitting.
Last implementation review: 28 July 2026.
PDF crop units and common uses
| Goal | Useful starting point | What to check |
|---|---|---|
| Remove scanner borders | Detect content with 2–4 mm padding | Shadows, page numbers, handwritten edge notes, and punched holes |
| Tighten a slide deck | Enter equal margins or drag one representative page | Different slide sizes and objects that extend past the visible slide |
| Prepare artwork | Use points or millimetres for exact edges | Bleed, trim marks, printer requirements, and colour-management workflow |
| Hide sensitive information | Do not use cropping as redaction | Use a permanent redaction workflow and verify the exported file |
Frequently asked questions
Does my PDF get uploaded?
No. The selected PDF is read and processed in browser memory. Normal page resources such as analytics and ads may still make network requests, subject to consent choices, but this tool does not include your PDF bytes in those requests.
Does cropping permanently delete hidden PDF content?
No. Cropping changes the visible page boundaries; it is not secure redaction. PDF objects outside the new page bounds may remain in the file and can sometimes be recovered with specialist software.
Will text remain selectable after cropping?
Usually yes. The export changes PDF page boxes and does not intentionally turn pages into images, so ordinary text and vector graphics remain in their original form.
How does automatic white-margin detection work?
The browser renders each selected page to a temporary canvas, finds pixels that differ from near-white, adds the chosen padding, and uses that rectangle as the crop. Review pages with faint marks, coloured paper, shadows, or edge content manually.
Can different pages have different crop settings?
Yes. Adjust each page independently, or apply exact physical margins to a page range or every page. Automatic detection calculates a separate content boundary for each selected page.
What do millimetres, inches, and points mean?
PDF dimensions use points: 72 points equal 1 inch, and 1 inch equals 25.4 millimetres. Unit changes convert the displayed values without changing the selected crop.
Are rotated and mixed-size pages supported?
Yes. The crop is stored relative to each page as it appears in the preview, while export converts the visible rectangle back to PDF coordinates. Review the result because unusual page-box or rotation metadata can behave differently between PDF viewers.
Are password-protected PDFs supported?
No password is requested. If the browser libraries cannot open or modify an encrypted or permission-restricted PDF, use an authorized unlocked copy.
Is there a file-size or page limit?
The page accepts one PDF up to 200 MB. Manual cropping has no fixed page-count limit beyond available browser memory; automatic detection is limited to 200 pages per action to protect browser responsiveness.
What should I check before sharing the result?
Open the downloaded PDF in the viewer the recipient is likely to use. Check every cropped edge, page orientation, page size, forms, links, annotations, and any print or submission requirements.