Crop PDF Free — Trim Margins and Pages Online
Crop PDF pages online free. Remove margins, trim white space, or select a custom crop area for all pages or individually. No signup.
About Crop PDF
Crop PDF lets you permanently trim the visible area of every page in a PDF — removing white margins, scanner borders, header/footer bands, or any rectangular region you want to cut — using PDF-lib's CropBox manipulation engine, entirely in your browser. Draw the crop rectangle in the visual preview, set exact pixel/point measurements, or choose from quick presets (remove margins, letterbox, square) and the tool writes the new MediaBox and CropBox values directly into the page dictionary. Unlike Acrobat's crop which only sets the CropBox (leaving hidden content intact), this tool optionally applies a content-clip stream that permanently removes content outside the crop boundary from the PDF structure, reducing file size. The visual preview uses PDF.js to render a live before/after so you can verify the crop frame before committing.
Most browser-based PDF croppers give you a single crop rectangle applied identically to every page — useless for documents where page 1 is a full-bleed cover and the rest are standard A4. This tool supports per-page crop rectangles, a uniform-all-pages mode for batch trimming, and a smart "auto-detect margins" algorithm that samples the rendered page pixels to find the minimal bounding box of content, automatically proposing tight crop coordinates. All client-side, no file uploads, up to 100 MB.
How We Compare
Compared to desktop alternatives like Adobe Acrobat Pro (starting at $19.99/month), Smallpdf ($12/month for unlimited), or iLovePDF ($9/month Premium), PDF AI Tools delivers comparable quality at $0 for the core feature set. We skip the subscription friction by processing most operations directly in your browser with WebAssembly — no server infrastructure costs to pass on to users. Our AI features (summarization, chat, OCR) use a pay-as-you-go backend that keeps your total cost well under $5/month even for power users.
How to Use Crop PDF Free — Trim Margins and Pages Online
- Step 1: Upload your PDF — PDF.js renders a preview of page 1 at full width with a draggable crop rectangle overlay
- Step 2: Drag the four handles to frame the content you want to keep, or type exact coordinates in the Left/Right/Top/Bottom fields
- Step 3: Choose uniform (same crop for all pages) or per-page mode; for per-page, navigate using the page arrows and set each crop individually
- Step 4: Toggle "Permanently remove content outside crop" if you want a smaller output file (irreversible); leave off for CropBox-only trimming
- Step 5: Click Crop PDF — PDF-lib updates the page dictionaries in the browser; a before/after preview confirms the result
- Step 6: Download the cropped PDF
Why Choose PDF AI Tools
We've built PDF AI Tools to replace expensive desktop software like Adobe Acrobat for 95% of common document workflows — at zero cost to you. Unlike competitors who gate features behind paywalls, add watermarks, or limit file sizes, our tools are genuinely free and genuinely unlimited. Your privacy matters: files processed client-side in your browser never touch our servers, and even AI-powered features use encrypted, auto-deleting processing pipelines.
Key Features
- Visual drag-to-crop interface — draw the crop rectangle on a PDF.js preview with precise handles at all four corners
- Exact coordinate input — enter Left, Right, Top, Bottom values in points (1 pt = 1/72 inch) for print-precise trimming
- Uniform crop mode — apply identical crop to all pages in one click (e.g. trim a 5mm scanner border from every page of a scanned book)
- Per-page crop — set different crop areas for odd/even pages, cover page, or any individual page
- Auto-detect margins — samples rendered pixels to find the tightest content bounding box and pre-fills crop coordinates
- Quick presets — "Remove margins" (tight crop), "Letterbox" (16:9), "Square", "A4", "Letter"
- Content-clip option — optionally permanently removes content outside crop (reduces file size); off by default (CropBox only)
- Preserves annotations, form fields, and bookmarks within the crop boundary; removes those outside
Frequently Asked Questions
What is the difference between CropBox-only and permanently removing content?
CropBox-only changes what is displayed and printed but the hidden content remains in the PDF file structure — Acrobat's "reveal hidden content" can restore it. Permanently removing content clips the page content stream so the hidden material is physically erased. Use permanent removal when sharing documents where off-screen sensitive content must not be recoverable.
Will cropping break hyperlinks and bookmarks?
Annotations and bookmarks that fall within the cropped area are preserved. Those outside the final crop boundary are removed (for permanent-removal mode) or hidden (for CropBox mode). Links in the main body copy are almost always within the content area and survive cropping.
Can I undo a crop after downloading?
CropBox-only crops are reversible — open the file again, reset coordinates to the full page size, and re-download. Permanent-removal crops cannot be undone once the file is saved; the clipped content is gone. We recommend keeping the original file as a backup.
Does this work on scanned PDFs with image-only pages?
Yes. Scanned PDFs are cropped by adjusting the MediaBox/CropBox coordinates, which clips the image regardless of whether the page content is text or raster. The auto-detect-margins feature also works by pixel-sampling the rendered image.
What units are the crop coordinates in?
PDF coordinates are in points (1 inch = 72 points). The tool displays a pts label and converts to/from millimeters and inches if you switch the unit selector. A standard A4 page is 595 × 842 pt; US Letter is 612 × 792 pt.