pdfcosmos

Halve PDF Pages

Split two-up scans back into single pages. The cut snaps to the gutter between them, not a blind 50%.

Free, fast, and privacy-first.

Split your PDF pages in half

or drag & drop files here

PDF files onlyone file at a timeup to 100 MB each

Split PDF pages in half, free, in your browser

When a scan or an export puts two pages on one sheet, Halve PDF Pages cuts each sheet back into two single pages. It is the tool for book, magazine, and newspaper scans that captured a whole spread at once, for A3 sheets that are really two A4 pages side by side, and for any two-up export you would rather read one page at a time. Everything runs on your device, so scanned books, records, and archives are never uploaded.

The part that matters most is where the cut lands. Most tools slice at a flat 50%, which is fine until the spread is even slightly off-centre — and a tightly-bound book scan almost always is, which is how you end up with a sliver of the next page on every sheet and text shaved off the inner edge. This tool scans each page in your browser first, measures where the ink actually is, and cuts through the middle of the widest blank gutter it finds. Pages are measured individually, so a scan that drifts from sheet to sheet is still cut correctly on every one.

The safeguards matter as much as the detection. The search only looks at the central part of the page, so a generous outer margin can never be mistaken for the gutter, and the final cut is always held between 15% and 85% of the page width or height. If a page has no usable gap at all — a dense page of text, or a photo that bleeds edge to edge — it falls back to a clean 50% rather than guessing. A page that cannot be analysed at all still splits; it just splits down the middle.

Choose left/right for side-by-side spreads or top/bottom for stacked pages, and the halves come out in reading order. A scan whose cover and back are single pages is handled too: set “Cover pages” to keep the first, the last, or both whole, and only the two-up pages between them are split. Nothing is rasterized: each half is a real copy of the source page with its visible area narrowed, so text stays selectable and searchable and the quality is untouched. It is the exact inverse of Multiple Pages Per Sheet, and a different job from Split PDF (which divides a document into files) or Crop PDF (which trims margins without changing the page count).

  • Cuts at the gutter, not at 50%

    Each page is measured for its blank gutter so the cut misses your text.

  • Text stays selectable

    Halves are cropped copies, never screenshots — no quality loss, no re-typing.

  • Rotation-aware

    The cut follows the visual page, even when it's rotated.

  • Private by design

    Processed in your browser. Nothing is uploaded.

How to split PDF pages in half

  1. Add your PDF

    Click “Add PDF”, or drag a single file into the upload area.

  2. Choose the cut

    Split each page into left/right halves (for side-by-side scans) or top/bottom halves. If your scan has a single-page cover or back, set “Cover pages” to keep it whole.

  3. Split & download

    Click “Split pages” to get a PDF with twice as many pages, one half each, in your browser.

Frequently asked questions

Are my PDF files uploaded to a server?
No. The split happens entirely in your browser (pdf-lib). Your file never leaves your device. You can confirm it in your browser's Network tab.
What is this for?
Scans and exports often capture two book or magazine pages on one wide sheet. Halving splits each sheet back into two single pages in reading order, the inverse of putting two pages on one sheet.
Left/right or top/bottom: which do I pick?
Use left/right for side-by-side (landscape) scans, and top/bottom for pages stacked vertically. The halves come out in reading order (left then right, or top then bottom).
Will the split cut through my text?
It tries not to, and this is the part most tools get wrong. Before splitting, every page is scanned in your browser for the blank gutter between the two halves, and the cut snaps to the middle of the widest gap instead of a blind 50%. The search is deliberately limited to the central part of the page so a wide outer margin can never win over the real gutter, and the final cut is always kept within 15% and 85% of the page, so no page can be lopsided enough to lose content. If a page genuinely has no clear gap — a dense page, or a full-bleed photo — it falls back to an exact half.
How do I split an A3 PDF into two A4 pages?
Add the file, choose “Into left & right halves”, and split. An A3 sheet in landscape is exactly two A4 portrait pages side by side, so each half comes out at A4. The same works for any two-up sheet: each half keeps the exact dimensions of the area it was cut from, so a Tabloid/Ledger sheet halves into two Letter pages.
Can I turn a scanned book into single pages?
Yes, that's the main thing this tool is for. Book, magazine, and newspaper scans usually capture a two-page spread on one wide sheet. Choose left/right and every spread becomes two separate pages in reading order, so the result reads and prints like a normal document. Because the cut hunts for the gutter between the two pages, the inner margins of a tightly-bound book are handled far better than a fixed 50% split.
Will the text stay selectable and searchable?
Yes. The halves are not screenshots. Each output page is a real copy of the source page with its visible area set to one half, so all the original text, fonts, and vector graphics survive exactly as they were — you can still select, search, and copy text, and the quality does not drop. Nothing is rasterized at any point.
Is the other half really removed from the file?
Not permanently. Splitting sets each output page's visible box (its CropBox and MediaBox), so viewers show only the half you asked for, but the other half's content still exists in the file and could be recovered by re-cropping to a larger area. That is fine for scans and reading copies. If a page contains something that must be destroyed rather than hidden, use a dedicated redaction tool first.
Does it work on rotated pages?
Yes. The cut follows the page as you see it on screen, so rotated pages split along the correct visual edge. The gutter scan uses the same visual orientation, which means a rotated two-up scan is measured the way you actually read it rather than the way it happens to be stored.
What if my scan has a cover page that shouldn't be split?
Use the “Cover pages” setting. A two-up book or magazine scan usually has a single-page cover and back page, and splitting those would cut the artwork down the middle. Choose to keep the first page whole, the last page, or both, and those pages are copied through untouched while every page between them is still split at its gutter. Leave it on “Split every page” if your file is two-up from start to finish.
How is this different from Split PDF or Crop PDF?
Split PDF divides one document into several files at page boundaries — it never changes a page itself. Crop PDF trims the same margin off pages and keeps the page count the same. Halve PDF Pages is the only one of the three that turns one page into two, doubling the page count. It is also the exact inverse of Multiple Pages Per Sheet, which puts several pages onto one sheet.
Is Halve PDF Pages free?
Yes, it's completely free to use, with no sign-up and nothing to install.