Split PDF Pages in Half

When a book or a magazine is scanned open on a flatbed, each PDF page holds two book pages side by side. Splitting them makes the file readable on a phone or e-reader, fixes page numbering and lets you print single pages. This tool cuts every page into a left and right half (or top and bottom) without re-rendering anything, so the quality stays exactly the same. It runs in your browser.

How to use this tool

1. Drop the PDF with the two-page spreads.
2. Keep "Left and right halves" for books, or choose top and bottom.
3. Move the cut position if the spine is not exactly in the middle, and choose right-first for manga or Japanese and Arabic books.
4. Keep the first or last page whole if they are single covers, then download.

Formula

Left half = [0, p × W] · Right half = [p × W, W], where p is the cut position and W the displayed page width

Each half is a copy of the original page whose visible area (media and crop box) is limited to that half, so nothing is re-encoded. The halves are computed on the page as you see it and mapped back through the page rotation, so rotated scans split correctly. "Only split pages wider than tall" leaves single portrait pages, such as an inserted title page, untouched.

Example

A scanned paperback of 120 landscape pages, each 842 × 595 pt with two book pages, becomes 240 pages of 421 × 595 pt. With the covers scanned as single pages, ticking both "keep whole" options gives 2 + 118 × 2 = 238 pages.