Crop a PDF and trim its margins
Adjust a box on the preview, type the margins to the millimeter, or let the tool find the white borders of each page. Cropping is lossless: the content is neither compressed nor converted.
- Free
- No quality loss
- Margins detected
- 100% private
100% private — Everything is processed directly in your browser: your files, voice, and image are never sent to Chatzam's servers.
How to crop a PDF
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Upload your PDF
Drop the file above: a preview of the first page appears with a crop box.
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Set the crop box
Drag the handles, draw a new box, enter the margins in mm or click “Detect” to find the white margins.
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Download the cropped PDF
Choose which pages to apply it to, check the result with the “After” preview, then download.
Precise, lossless cropping
White margin detection
Each page is analyzed to find the area that's actually printed, with an adjustable safety margin so nothing gets cut off.
All pages or just a few
Apply the same box to the whole document, to odd or even pages (handy for scanned books), or to a single page.
Original quality
Text stays text and images aren't recompressed: only the visible area of the page changes.
Processed locally
The PDF is cropped in your browser. It isn't sent anywhere, and nothing is kept once you close the page.
Trim margins for more comfortable reading
Many PDFs are laid out for print, with wide white margins around the text. On an e-reader, a tablet or a phone, those margins shrink everything and force you to zoom in constantly. Trimming them lets the text fill the screen and makes it much easier to read. Cropping is also useful for isolating a diagram, a table or a signature before using it elsewhere, removing the black edges of a scan, or getting rid of crop marks on a print-ready file. Set the box on one page, apply it to the whole document and check the result with the “After” preview before downloading.
How automatic detection works
The tool renders each page in memory, then looks for the rows and columns that contain ink: everything white around them counts as margin. Isolated specks of dust from a scan are ignored. A safety margin, 3 mm by default, is then added back so the crop doesn't hug the text. If “Same box for all pages” is checked, the tool keeps, for each edge, the smallest margin found across all pages: no page gets cut off and they all keep the same size. Uncheck it to fit each page to its own content, for example on a scan where the sheet isn't always in the same position.
Lossless and reversible cropping
A PDF defines a visible area for each page, called the CropBox. The tool only changes that area: the page content is neither turned into an image nor recompressed, the text stays selectable and the file stays about the same size. PDF readers, browsers and printers then show only the part you chose. The flip side: anything outside the box is hidden, not erased, and specialized software can bring it back. If you want to remove information for good, use the redaction tool instead, which truly deletes the hidden content.
Frequently Asked Questions
Does cropping reduce quality?
No. Only the visible area of each page changes: the text, images and fonts are exactly those of the original file.
Can I crop odd and even pages differently?
Yes. Choose “Odd”, set the box, then switch to “Even” and set another one. It's handy for a scanned book whose binding alternates between left and right.
Is the content outside the box deleted?
No, it's only hidden: cropping is reversible. To permanently remove confidential information, use the “Redact PDF” tool.
Is my PDF uploaded to a server?
No. The preview, margin detection and cropping all happen in your browser: the file stays on your device.
My PDF is password protected. What can I do?
An encrypted PDF can't be modified. First remove the protection with the “Unlock PDF” tool (you'll need the password), then crop the unlocked copy.