Crop PDF
Crop PDF
Trim white margins or crop to any region — drag the box, enter exact margins, or auto-detect. Nothing is uploaded.
- Runs in your browser
- Nothing uploaded
- No sign-up
- Free, no daily limits
- 1Add your file
- 2Choose settings
- 3Download
Drop a PDF here
Choose a fileSelect a PDF to crop · up to 100 MB · nothing is uploaded
100% Private: All cropping happens in your browser. Your PDF never leaves your device.
Your file is safe
It is processed inside this browser tab and never uploaded, and it is gone when you close the page.
Good to know
- Margins are in PDF points: A4 is 595 × 842 pt, so 36 pt is half an inch.
- Auto-trim finds the white edges of the page and snaps the box to the content.
- Text stays selectable and images keep their resolution.
Crop PDF Free Online
Crop PDF is a free, in-browser tool that trims a PDF's page area without uploading your file. Drag the crop box over the part you want to keep, type exact margins in points, or hit Auto-trim white margins to snap the crop to the content automatically. Apply it to a single page or the whole document, then download: all processed locally on your device.
Why Use TryDocsy to Crop PDFs?
No Upload Required
All cropping happens in your browser. Your PDF never leaves your device.
Visual Crop Box
Drag and resize the box with live rule-of-thirds guides.
Exact Margins
Type precise top / right / bottom / left values in points.
Auto-Trim Margins
One click measures the current page and hugs its content.
All Pages or One
Apply the same crop everywhere, or just the current page.
Free & Rotation-Aware
No account, no watermark; handles rotated pages correctly.
Last updated
Crop PDF changes how much of each page is visible: you drag a box over the area worth keeping, or enter exact margins, and the tool writes a new visible boundary into the file. The page is rendered by pdf.js so the preview matches the real page, including its orientation, and every measurement displays in PDF points (72 points to the inch) alongside inch equivalents, such as Crop size: 421 x 595 pt (5.85 x 8.26 in).
Cropping adjusts the page's CropBox, which represents the rectangular area a viewer displays. Content outside that boundary remains inside the file structure, which is why a cropped download does not shrink in file size and why text cropped out of view can still be extracted by search indexing or screen readers. This makes cropping ideal for tightening scans, slides, and print margins, but unsuitable for concealing private numbers. Use Redact PDF to permanently delete sensitive text from the content stream.
How it works
1. Open a PDF
Drop a single .pdf file up to 100 MB onto the upload area. The first page renders immediately; for multi-page documents, arrows and a page counter above the preview move through the document.
2. Set the area to keep
Drag inside the shaded rectangle to reposition it, or pull any of the eight handles to resize the box. The numeric margin fields (Top, Right, Bottom, Left in points) accept typed values, and Reset restores margins to zero.
3. Or auto-trim white margins
Click Auto-trim white margins. The tool renders the current page onto a canvas, detects outermost non-white pixels, and sets margins to hug document content with approximately four points of breathing room.
4. Choose scope and download
Select All pages (default) or This page. The button reflects your action (such as Crop all 18 pages) and activates once margins are set. Click Download Cropped PDF; the output appends -cropped to the filename.
When you'd use it
Tightening scans with broad white borders
Flatbed and phone scans frequently carry wide blank frames that waste screen space. Auto-trim pulls the boundary in to the writing itself, making document text appear larger and easier to read on mobile devices.
Formatting presentation slides for handouts
Slide decks exported to PDF often sit within wide margins with unwanted footer strips. Cropping off the border strips makes slides larger and clearer when combining pages with /pdf/n-up.
Cropping receipts and invoices down to content
A scanned receipt centered on an A4 sheet is easier to read and archive when trimmed down to the slip dimensions. Setting custom margins produces a compact page hugging the transaction details.
Removing decorative headers before sharing
When a header bar or repeated logo banner is cosmetic rather than sensitive, cropping the top margin trims it away cleanly while leaving the remaining page layout pixel-identical.
What do the margin measurements and points mean?
Margins are measured in PDF points from each edge, where 72 points equal one standard inch. An A4 page measures 595 x 842 points, while US Letter measures 612 x 792 points. Setting a 36-point margin trims exactly half an inch off that side.
The tool enforces a minimum safety dimension: it always retains at least 10 points (approximately one-seventh of an inch) in both horizontal and vertical directions. If you pull a handle past this limit, the opposing margin yields rather than allowing the page boundary to collapse.
Rotated pages are handled in their displayed orientation. The preview applies the document's internal rotation, records your crop box against that view, and converts coordinates back to the underlying matrix before saving.
| Paper format | Width (pt) | Height (pt) | Dimensions (mm) | Dimensions (in) |
|---|---|---|---|---|
| A4 Standard | 595 pt | 842 pt | 210 x 297 mm | 8.27 x 11.69 in |
| US Letter | 612 pt | 792 pt | 215.9 x 279.4 mm | 8.50 x 11.00 in |
| US Legal | 612 pt | 1008 pt | 215.9 x 355.6 mm | 8.50 x 14.00 in |
| A5 Note | 420 pt | 595 pt | 148 x 210 mm | 5.83 x 8.27 in |
Source: ISO 216 Paper Sizes / Adobe PDF Reference, checked October 28, 2026
How does the auto-trim white margins detector work?
Auto-trim rasterizes the visible page at a resolution of roughly 1,000 pixels across and scans pixel color values against a white canvas. A pixel counts as background when it is transparent or when its red, green, and blue color channels all measure 245 or higher out of 255.
This brightness threshold treats subtle off-white tints as margin space while preserving light-gray line work and watermarks. However, scanner shadow along page spines or dark dust particles are detected as content; if dark borders prevent trimming, drag the handles inward manually to complete the crop.
Auto-trim analyzes only the page displayed on screen. When All pages is selected, those calculated margins apply to every page in the file. Check multiple pages before applying uniform margins if your PDF mixes landscape diagrams with portrait text.
Does cropping delete content outside the box?
No. Cropping updates the /CropBox boundary in the page dictionary without deleting underlying data streams. The original text operators and bitmap resolutions remain in the file. Compliant viewers display only the cropped window, but software ignoring the CropBox can still access hidden content. Use Redact PDF to permanently delete private data.
Because nothing is re-encoded, file size remains approximately unchanged. If you need a smaller file after cropping away empty borders, use Compress PDF. Password-protected documents cannot be cropped directly; unlock them first with Unlock PDF.
Decision rule: Crop vs Redact vs Compress
Crop PDF sets the page's crop box. Viewers then show only that area, but the text and images outside it stay in the file, so a text extractor can still read them.
Use this decision guide to select the right utility for your document:
- **Use Crop PDF** when trimming scanner margins, centering off-center content, or preparing slide handouts where vector typography and full sharpness must be preserved.
- **Use Redact PDF** when hiding confidential numbers, personal names, or signatures. Redaction flattens target pages into raster graphics so text cannot be recovered.
- **Use Compress PDF** when your file is too heavy for an email attachment or portal submission and needs to shrink from megabytes down to kilobytes.
Frequently asked questions
Does cropping permanently delete hidden content from the file?
No. Cropping sets a smaller display rectangle (CropBox). The content outside that boundary stays in the PDF and can still be extracted by text tools. Use /pdf/redact to permanently delete sensitive text.
Why did my file size not decrease after cropping?
Cropping modifies page display boundaries rather than recompressing or stripping data. To reduce file weight after trimming margins, run the document through /pdf/compress.
Can I crop different pages with different margins?
Yes, by cropping in passes: set margins for the current page, select This page, download the result, then open that download and crop the next page.
How does the auto-trim feature detect empty margins?
It renders the page, treats pixels with RGB values of 245 or higher as empty background, determines the bounding box of the remaining content, and adds four points of padding.
Why is the crop button disabled when I open a PDF?
The button stays disabled until at least one margin is greater than zero. Drag any handle or enter a numeric margin to activate the crop action.
Are the margin inputs measured in millimeters or points?
Margins use PDF points, where 72 points equal one inch (roughly 28.35 points per centimeter). The live readout displays the dimensions in both points and inches.
Will rotated or landscape pages crop correctly?
Yes. The preview accounts for the document's internal rotation, and the tool converts margin coordinates back to the native coordinate system before writing the CropBox.