Crop PDF
Trim white margins or crop to any region — drag the box, enter exact margins, or auto-detect. Nothing is uploaded.
Drop a PDF here
Select a PDF to crop
Max file size: 100MB
100% Private: All cropping happens in your browser. Your PDF never leaves your device.
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.
Crop PDF changes how much of each page is visible: you drag a box over the part worth keeping, or type exact margins, and the tool writes a new visible area into the file. The page you see is rendered by pdf.js so the preview matches the real page, including its rotation, and every measurement is shown in PDF points — 72 points to the inch — alongside the equivalent in inches, as in “Crop size: 421 × 595 pt (5.85″ × 8.26″)”.
One thing to be clear about before you rely on it: cropping sets the page's CropBox, the rectangle a viewer is asked to display. Whatever sat outside the box is still inside the file, which is why the cropped download is not smaller than the original and why a header you cropped away can still be pulled out by text extraction. That is the correct behaviour for tightening scans, slides and print layouts, and the wrong tool for hiding a name or an account number — use /pdf/redact for that.
How it works
1. Open a PDF
Drop a single .pdf of up to 100 MB onto “Drop a PDF here”. The first page is rendered straight away; with more than one page, arrows and a “3 / 18” counter above the preview move you through the document.
2. Set the area to keep
Drag inside the shaded box to move it or pull any of the eight square handles to resize it, with rule-of-thirds guides shown across the box. The four numeric fields under “Margins (pt)” — Top, Right, Bottom, Left — accept typed values instead, and the Reset link puts them all back to zero.
3. Or auto-trim the white border
“Auto-trim white margins” re-renders the current page onto a white canvas, finds the outermost non-white pixel on each side and sets the margins to hug that content, leaving roughly four points of breathing room around it.
4. Choose the scope and crop
“All pages” (the default) or “This page” decides how far the crop reaches. The action button names what it will do, for example “Crop all 18 pages”, and stays disabled until a margin is actually set. Then press “Download Cropped PDF”; the file keeps its name with -cropped added.
When you'd use it
Tightening a scan with wide borders
Flatbed and phone scans usually carry a broad white frame that wastes space on screen and on paper. Auto-trim pulls the page in to the writing itself, so the text fills more of the screen when it is read on a phone.
Turning slides into readable handouts
Slide decks exported to PDF often sit inside a large blank canvas with a footer strip. Cropping the strip away and tightening the edges makes each slide larger when several are printed on one sheet with /pdf/n-up.
Cutting a receipt page down to the receipt
A scanned bill in the middle of an A4 sheet reads better as a small page than as a stamp in the corner of a big one. A crop around the receipt gives a page that fits the content.
Removing a printed header band before sharing
Where a header or footer band is cosmetic rather than sensitive — a template strip or a repeated logo bar — cropping it off is quick and keeps the rest of the page pixel-identical.
Points, limits and what the numbers mean
Margins are measured in PDF points from each visible edge, and the fields show whole numbers while the crop itself keeps the fractional value you dragged to. A4 is 595 × 842 pt and US Letter is 612 × 792 pt, so a 36 pt margin is half an inch off that side.
The tool refuses to crop a page out of existence: it always leaves at least 10 points, about a seventh of an inch, in each direction. Push a handle past that point and the opposite margin gives way instead of the page collapsing.
Rotated pages are handled in the orientation you see. The preview applies the page's own rotation, your margins are recorded against that view, and they are rotated back into the page's underlying coordinate system before the crop box is written, so cropping the top of a sideways scan really does trim the top of what you were looking at.
How auto-trim decides what is white
Auto-trim rasterises the page at a working resolution of about 1,000 pixels across, paints it onto a white background and then scans the pixels. A pixel counts as background when it is fully transparent or when its red, green and blue values are all 245 or higher, so a faint grey tint is treated as empty space while genuine light-grey artwork is kept.
That threshold is also why a scan with a dark edge, a shadow along the spine or speckles of dust trims less than you hoped: those specks are content as far as the detector is concerned. Fixing the scan is out of scope here, but you can always drag the box in manually afterwards.
Auto-trim looks only at the page currently on screen. With “All pages” selected, the margins it finds are then applied to every page in the document, which is exactly what you want for a uniform scan and wrong for a document that mixes portrait text pages with a wide table. Step through a few pages and check the box before cropping the lot. A page with nothing on it stops with “This page looks blank — nothing to trim.”
What cropping does not change
The file size stays roughly where it started, because nothing is deleted or re-encoded — the crop is a new rectangle recorded on each page. The images keep their resolution, the text keeps being selectable text, and a viewer that ignores the crop box, or a tool that reads the raw page, can still reach the hidden area.
Printing follows the crop: most printers place the smaller page on your paper and leave the rest blank, or scale it up if you ask them to fit the sheet. If you need the trimmed page to become the real page size for a print shop, say so when you send it, or check the result in the print preview first.
A password-protected document cannot be cropped here. Loading stops with a message pointing you at the PDF Unlock tool; unlock the file there and crop the unlocked copy.
Frequently asked questions
Does cropping actually delete the hidden content?
No. It records a smaller visible rectangle on the page, so the content outside it stays in the file and can still be extracted by other software. Use /pdf/redact when the point is to remove information rather than to tidy the page.
Why is my cropped PDF the same size in megabytes?
Because nothing was thrown away or recompressed. If the goal was a smaller file, follow the crop with /pdf/compress, which does re-encode the page content.
Can I crop one page differently from the rest?
Yes, by cropping in passes: set the margins, choose “This page”, crop and download, then open that download again and crop the next page. A single pass applies one set of margins to whatever scope you selected.
What does the auto-trim button use to find the content?
It renders the current page, treats any pixel lighter than 245 on all three colour channels as background, takes the bounding box of everything else and adds about four points of padding around it.
Why can't I press the crop button?
It stays inactive while all four margins are effectively zero — the label then reads “Drag or enter margins to crop”. Drag a handle or type a margin and it becomes active.
Are the margins in millimetres?
No, they are PDF points, at 72 to the inch. Roughly 28.35 points make a centimetre, and the readout under the preview also shows the resulting page size in inches.
Will a rotated or landscape page crop correctly?
Yes. The preview shows the page the way a viewer does, and the margins you set there are converted back into the page's own coordinates, including for pages rotated 90, 180 or 270 degrees.