tooloora

Crop PDF — trim margins & select an area, losslessly

Draw the crop area or auto-detect white margins, apply it to all pages or a range — lossless via the page geometry, no rasterizing, no upload.

Runs locally — nothing is uploaded

Drop a PDF here or click

Processed locally, no upload

Runs locally in your browser — no upload.

Crop a PDF losslessly right here: draw the crop area over the preview or auto-detect the white margins, apply it to all pages or a range, download. Only the page rectangles change — text stays selectable, nothing is rasterized, and the file never leaves your browser. One thing matters: cropped-away content becomes invisible, but it is not deleted.

How do you crop a PDF?

  1. Drop your PDF — the first page appears as a preview, and everything stays local on your device.
  2. Drag the area that should stay visible with your mouse or finger, or click “Detect margins”: the tool then measures the printed area of the current page and frames it with a little breathing room. The display shows the resulting size in millimetres.
  3. Choose whether the crop applies to all pages or only to a range like “1-3, 5”, then crop and download.

The selection is stored as a fraction of the visible page, so it lands on the same spot of every selected page — including pages that are displayed rotated and documents with mixed page sizes. There is deliberately no separate frame per page: if some pages need a different crop, run the tool again with a page range.

Why is there no quality loss?

Because no image is ever created. A PDF carries several rectangles per page: the MediaBox is the sheet, the CropBox the part of it a viewer shows. The PDF standard ISO 32000-1 defines the CropBox as the visible region to which the page content is clipped when displayed or printed (clause 7.7.3.3, Table 30). This tool shrinks exactly that rectangle — only a few numbers change per page. Text stays selectable and searchable, vectors stay sharp, fonts stay embedded, form fields keep working, and the file size stays practically the same. Many online services render the pages to images instead: the result looks similar but is a photo of your document — often several times larger, with no text layer.

The millimetre display uses the standard’s own unit, by the way: per ISO 32000-1, PDF user space measures in points of 1/72 inch — an A4 page is 595 × 842 points.

Is the cropped-away content deleted?

No — and that is the most important sentence on this page. Cropping only shrinks the visible area; everything outside it remains fully in the file and can be made visible again with other software. You can verify this yourself: the file does not get smaller by cropping. For margins, scan edges and punch holes that is exactly right. But to permanently remove names, numbers or whole paragraphs, use Redact PDF — it physically removes marked areas from the page instead of merely hiding them.

When is automatic margin detection worth it?

For scans and documents with evenly white margins. The detection examines the preview of the current page row by row and column by column: anything brighter than typical paper white counts as empty, and a single speck of dust will not blow the frame open. A narrow safety margin is kept around the detected content. Honest limits: it measures the page currently shown — if other pages have clearly different margins, check the result there in the preview. On an empty page the detection finds nothing, and says so.

What about print-ready PDFs?

Print-ready PDFs often carry additional rectangles such as the TrimBox (the finished size after trimming). If it stuck out beyond the visible area after cropping, the file would violate the standard — so existing trim, bleed and art boxes are clipped into the new crop area. Pages without such entries do not get invented ones: where the TrimBox is absent, ISO 32000-1 (Table 30) makes the CropBox its default value.

Frequently asked questions

Is my PDF uploaded to crop it?

No. Cropping runs entirely in your browser; the file never leaves your device. The tool changes a few numbers per page inside the PDF — nothing is sent anywhere and nothing is stored.

Is the cropped-away content deleted?

No — and that matters. Cropping only shrinks the visible area of each page; everything outside it stays in the file, invisible but recoverable with other software, which is also why the file size barely changes. That is fine for margins and layout. Never crop away confidential content: use the Redact tool instead — it physically removes what you mark.

Does cropping reduce quality?

No. Nothing is re-rendered or turned into an image. Only the page rectangles are updated, so text stays selectable and searchable, vector graphics stay sharp, embedded fonts stay embedded, and form fields keep working.

Can I crop only some pages — and what about rotated pages?

Yes. Apply the selection to all pages or to a range like '1-3, 5'. The selection is stored as a fraction of the visible page, so it lands on the same spot of every selected page — including pages that are displayed rotated or have unusual sizes.

What happens to print marks like the trim box?

A page that carries its own trim, bleed or art box gets it clipped into the new visible area, so no print specification sticks out of the crop. Pages without such entries do not get invented ones — per the PDF standard ISO 32000-1 the trim box then simply defaults to the crop box.