How do I crop a PDF online?

Select your PDF file on DocumentAlter. Drag the handles on the interactive visual bounding box to frame the desired area, or click 'Auto-Trim White Margins'. Choose whether to apply to all pages or the current page, then click 'Download Cropped PDF'.

Does cropping degrade image quality or vector text?

No! Our tool applies an ISO-standard CropBox directly to the PDF vector dictionary. Content outside the boundary is hidden from view while retaining 100% of the internal sharpness and text selection.

Can I auto-trim extra whitespace around scanned pages?

Yes. Simply click the 'Auto-Trim White Margins' preset button. The intelligent scanner detects empty space around your document borders and snaps the crop frame automatically.

PDFをトリミング Pages

Trim white page margins, remove unwanted headers or footers, and crop document boundaries with interactive visual handles. 100% private in browser memory.

PDFファイルを選択

またはここにPDFをドラッグ＆ドロップ to crop page margins

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210 × 297 mm

Smart Crop Presets:

Non-Destructive Vector Crop

Cropping modifies the PDF CropBox matrix without re-compressing images, retaining 100% original clarity.

document_cropped.pdf

Total: 1 Page Size: 0 KB

document_cropped.pdf

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How to Crop PDF Pages and Trim Margins

01. ファイルを選択

Load your PDF into browser RAM. The page is rendered instantly on our interactive canvas viewport.

02. Adjust Crop Area

Drag the corner or edge handles to crop unwanted areas, or click 'Auto-Trim White Margins' for 1-click trimming.

03. PDFをダウンロード

Click "Download Cropped PDF" to save your precisely framed publication with zero loss in resolution.

PDFをトリミング FAQs

Can I crop only one page without affecting other pages?

Yes! In the 'Apply Crop To' selector, choose 'Current Page Only'. Only the active preview page will be cropped.

Does cropping reduce the PDF file size?

Standard PDF cropping sets a new visible boundary (CropBox) for viewing and printing. If you also wish to permanently discard hidden data to minimize file size, pass your cropped document through our Compress PDF tool.