Trim what a PDF page shows, with a real preview
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Whole-pixel crops with the rectangle typed or dragged, checked by decoding the output and comparing it with the pixels that went in. Quarter turns and mirrors are exact permutations, so nothing is clipped.
Draw, type or upload a signature and place it on the page a reader sees, at a width you can state in inches, on one page or every page. Transparent, so it does not hide the line you are signing on.
Join PDFs into one document, with a bookmark for each file
Scanned pages have huge white margins that waste space when printed two-up.
Input
scan.pdf 612 x 792 pt · Trim to content
Output
CropBox [34, 31, 605, 761], showing 571 x 730 pt, MediaBox untouched, 0% of the ink hidden
Trim to content renders the pages, finds the ink on each, and keeps the tightest margin that works for all of them with six points of air added back, so the line under the preview reads zero marks hidden. Only the CropBox is written, so nothing is resampled and the crop is reversible: what falls outside is still in the file, which also means a crop is not a way to redact.
Trim the margins of PDF pages so the content fills more of the page. Set the four sides with sliders in points, inches or millimetres, take a preset, or press Trim to content and let the tool find the ink itself. The preview is a render of the actual page at its actual proportions, with the crop drawn on it and the part it hides dimmed, and it tells you how many of the marks on that page you are hiding. The arithmetic works from what each page currently shows, from where its box actually is, and through its own rotation, so a document of mixed sizes, mixed rotations and pages that were already cropped all come out right. One thing to be clear about: cropping writes a CropBox, which changes what a page shows. What falls outside is still in the file. This is not a way to redact anything.
Trim excessive whitespace from scanned documents or academic papers for easier reading on a small screen. Trim to content does it without a guess.
A flatbed leaves a black edge on every page. One linked slider takes it off all four sides at once, and the preview shows whether it is gone.
Set an exact inch or an exact number of millimetres per side, on all pages or a named range, working from each page's own box rather than from an assumed one.
Turn on Linked and drag any slider to 54 points, which is three quarters of an inch. All four margins follow, and the preview shows the border going and the ink staying.
Press Trim to content. On a page whose ink runs from x 40 to 598.9 and y 35.9 to 754.4, it sets margins of about 34, 7, 31 and 31 points, and the hidden-ink line then reads zero because nothing on the page is cut.
Set 100 points off the top. On pages at /Rotate 0, 90, 180 and 270 that writes four different boxes, and all four render 100 points shorter in the direction the reader is looking.
A crop is a CropBox. ISO 32000-1 clause 14.11.2 defines it as the region of a page to display or print, it must lie inside the MediaBox, and it defaults to the MediaBox when a page has none. Writing one changes what a page SHOWS. It does not change what the page CONTAINS, and this tool says so on the page rather than leaving you to find out: everything outside the box is still in the file, still extractable by anyone who opens it with the right tool, and a crop is therefore not a way to redact.
Three things follow from doing that arithmetic properly, and all three are places a cropper can be quietly wrong.
The margins come off what the page currently SHOWS, not off the MediaBox. On a page already cropped to an inset box, another ten points has to come off the inset box; measured against the MediaBox instead, "ten points more" can make the visible area BIGGER, which is not a crop.
They come off the box where it actually is. A MediaBox does not have to start at the origin, and offset boxes are ordinary in print work. Computing a crop as (margin, margin, width - margin, height - margin) puts it in the wrong place on any such page.
And "top" means the top you can see. /Rotate turns a page clockwise when it is displayed, so on a page at 90 the top of the picture is the left edge of the MediaBox. The tool maps each side through the page's own rotation, so a document whose pages are rotated differently all lose the same edge of what the reader sees.
The preview is a real render of the page at its real proportions, with the crop drawn on it and the hidden part dimmed, and underneath it a count: how many of the marks on this page the crop hides. Trim to content renders each page, finds the ink, and keeps the tightest margin that still works for every page with six points of air added back.
No, and this is the most important thing to know about it. Cropping writes a CropBox, which tells a viewer which part of the page to show. Everything outside it is still in the file and can be recovered by anyone who opens it with the right tool. To actually remove content, rasterise the pages or use proper redaction software.
No. Nothing is removed, so the size is about the same. If a smaller file is what you are after, the compressor is the tool for it.
The tool reads each page's rotation and maps your four sides through it, so "top" always means the top of what you are looking at. A page at /Rotate 90 has its crop taken off the left edge of its MediaBox, which is the same thing seen from the file's side.
Your margins come off what it currently shows, so cropping further always tightens. A cropper that measures from the MediaBox instead can make an already cropped page bigger when you ask for a smaller one.
Yes, because nothing was removed. Setting all four margins to zero on the cropped file restores its full MediaBox, and the text and graphics were never touched.
It renders each page, finds the bounding box of the marks on it, and takes the tightest margin that still works for every page it looked at (up to 24 of them), then adds six points of air back so the crop does not sit on the outermost pixel of a glyph.
PDF parsing and editing happen in your browser. Documents, and everything inside them, are never uploaded or stored remotely.