How to automatically trim white margins from PDF pages

1 min read·25 July 2026

Scanned documents and exported PDFs often have wide white margins around the content. With PDFrust's trimMargins tool you automatically cut those off for a tight, compact PDF.

When do you use trimMargins?

You have an A4 scan with a 2 cm white border all around (typical for flatbed scans). Or you have a PowerPoint export where each slide has a large white space. TrimMargins detects the outermost empty space and cuts it away automatically.

TrimMargins tool in PDFrust

Open the trimMargins tool. Upload the PDF. PDFrust analyses each page and detects the outermost white space. You set a threshold (how white is 'white'?) and choose whether to trim all pages uniformly or each page individually. Download the trimmed PDF.

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TrimMargins vs. crop

TrimMargins automatically cuts off empty borders based on page content. Crop lets you manually select a rectangular area per page. Use trimMargins for batches of scanned documents, crop for precise manual trimming.

Adjusting PDF page size

TrimMargins also adjusts the page size: after trimming the page is smaller than A4. Want to reset the page size to A4 after trimming? Use the resize tool to scale the page back to standard size.