Two pages per sheet, unreadable on every screen: split the book back into pages
Split a book scanned two pages per sheet into single pages: a movable gutter line in your browser, covers kept whole, right-to-left books supported.
UnboundPDF is a free suite of 53 PDF and image tools that run entirely in your browser — merge, split, compress, edit text, OCR in 126 languages, redact, sign, convert and archive to PDF/A. Your document is read and written by the page on your own device; there is no document-upload endpoint in the core tools, no account, no watermark and no daily cap. Every result can be checked — with the Network tab, or with the Document Passport the Workspace writes for a chain of steps.
Quick start. Open Split Book Scan, add the scan, put the line in the gutter — the suggestion finds the binding shadow on page 1 but only ever moves the line, never cuts on its own — mark covers don't-split, download single pages in reading order.
The scan that fights every reader
Two-up scans read fine on the scanner's glass and nowhere else: phone readers shrink the spread to illegibility, tablets force panning, printing gives you half-size pages. The book's own pages are in there — they just need the cut the scanner didn't make.
You hold the knife
One straight cut per sheet, at a line you can see and move, with per-sheet overrides where the binding drifted. The suggestion reads the darkest column near the centre — the shadow a bound book casts in its gutter — and where the profile is flat it says so instead of guessing. Nothing is cut until you run it.
Finishing the book
The output pages are images, as the scan was — stated before the run. The finishing chain: deskew the tilted ones, OCR for search (in the language the book is printed in — the scan-quality habits pay here), compress for the shelf. The full scanned-book walkthrough chains it end to end.
Troubleshooting
The gutter wanders through the book. Per-sheet override on the review strip — bindings sag; the line follows. The suggestion found nothing. Flat profile, stated honestly — a well-pressed book casts little shadow; place the line by eye. Pages came out swapped. Reading-order setting — left-first for Latin books, right-first for RTL.
Frequently asked questions
Why are book scans two pages per sheet?
A book on a flatbed photographs both pages at once. Fine for the scanner, wrong for every screen and printer afterwards.
My book reads right to left.
Pick right-page-first — the halves swap within each sheet so Hebrew, Arabic and manga books come out in reading order.
What about the cover?
Mark that sheet don't-split on the review strip; it passes through whole.
Try it yourself
Free, private, no account. Runs entirely in your browser.