Split on Blank Pages - Free Online Browser Tool

Cut a scanned document into separate chapter files wherever a blank page marks a break.

Some documents have chapters and some have blank pages. Scanned books often have both: a stack of photocopied chapters with a blank sheet wedged between each one, which the person who made the copy used as a placeholder so the stack stayed in order. That is a real convention and it is a useful one, because it means the structure is written into the pages themselves rather than into a table of contents that may not have survived the scan. This reads that structure. Each page is sampled for how much ink is on it, the pages with essentially none are treated as breaks, and everything between them becomes a separate file. A 300-page scan with four blanks in it comes back as five PDFs in one ZIP, named for the page numbers they cover, alongside a report saying which pages were used as breaks. The blank page itself is not in any of the chapter files. It is the divider, not part of either side, and including it would put a blank first page in front of every chapter. Leading and trailing blanks are handled too - a document that opens on a blank sheet does not produce an empty file, because a zero-page PDF will not open in a reader and is worse than no file at all. How blank counts as blank is a judgement, so the threshold is yours to set. A real page of text measures well above half a percent ink coverage; a blank one is almost exactly zero. Strict catches only pure white, Normal also catches the faint grey edge a scanner leaves, and Loose catches genuinely sparse pages such as a divider with a small ornament on it. If nothing is found, the tool says so and changes nothing, rather than quietly handing back the whole document with a chapter label attached - and if that is what you wanted anyway, there is an option for it. Scanning at this resolution is a judgement about what counts as ink, and a page that is nearly empty but not empty may read either way depending on the threshold you picked. Everything runs in this tab; the file is never uploaded.

This split on blank pages utility runs completely inside your web browser. Your document is opened locally and processed on your own device using JavaScript and WebAssembly, so your file is never uploaded to any server. There is no signup, no watermark and no limit on how many documents you can handle.

  • 100% client-side - files never leave your device
  • Instant processing, no upload wait
  • Works on desktop, tablet and mobile
  • Free forever, no account required

How to Use the Split on Blank Pages Tool

Four steps, and the whole thing runs locally on your own device.

  1. Add the scanned PDF

    One file. Each page is sampled at low resolution, which is a coverage question rather than a legibility one - the tool needs to know whether a page has ink on it, not read the ink.

  2. Set how strict the blank test is

    Strict for pure white pages, Normal for the grey cast a scanner leaves behind, Loose for near-empty pages with an ornament or a page number. A real text page measures over half a percent ink coverage, so there is a wide margin between that and a blank.

  3. Decide what happens if no blank page is found

    The default is to stop and say so, because a document with no breaks in it is not a document with one chapter you failed to split. You can also ask for the whole file back as a single part if that suits you.

  4. Save

    One ZIP: a numbered PDF per chapter, named for the pages it covers, plus a plain-text report listing the breaks and the page range in each part.

Frequently Asked Questions

Does the blank page end up in one of the chapter files?

No. It is the break between two chapters, not part of either one, so it is left out of both. Including it would mean every chapter opened with a blank first page. Blanks at the very start or end of the document are dropped the same way, and a run of two or more consecutive blanks counts as a single break rather than producing an empty file between them.

How does it decide a page is blank?

By measuring how much dark ink is on it. Each page is sampled small - around a tenth of its normal size - and the proportion of dark pixels is compared against a threshold. That is enough to tell an empty page from a page of text, which measure roughly one percent ink against essentially zero, and sampling small keeps a long scan fast.

My scan has a grey background and it finds nothing

Loosen the threshold. A scanner lid that was not quite closed leaves a grey cast that a strict test reads as ink on every page. Strict is for genuinely white scans, Normal handles a faint edge, and Loose is for scans where even that is not enough. If loosening it starts treating a real but sparse page as blank, that is the trade at the other end - a page with only a page number on it is genuinely close to the line.

What if the chapters are not separated by blank pages?

Then this is not the tool for the job, and it will tell you rather than pretend. It looks only for blank pages - it does not read headings or guess where a chapter starts. A document with real bookmarks can be split on those with Split by Bookmarks instead, and one with neither may need its ranges typed in by hand. If the job is the opposite way round - keeping only the pages that have something on them - Remove Blank Pages is the tool for that.

Can it split one file into separate downloads?

It produces a single ZIP, because a twelve-chapter document as twelve separate downloads is twelve browser prompts and a folder to clean up afterwards. The parts are named with their page ranges, so chapter_part03_pages_41-58.pdf says what it is without opening it.