Getting the empty pages out of a scanned PDF
A double-sided scan of single-sided paper comes out twice as long as it should be, with an empty page between every real one. Finding those by eye is the part nobody enjoys and nobody does accurately. This page is about when to hand that job to the check, when to do it yourself, and what to look at before you press remove.
Which tool you need
A long scan with empty backs scattered through it
This is the case the tool was built for. Every page is drawn and measured on your device, the empty ones arrive marked, and you look through them before anything happens.
You already know which pages to take out
Delete PDF pages is more direct. Waiting for every page of a long document to be checked is time spent on a question you have already answered.
The empty pages are at the end, not scattered
Delete PDF pages again. A trailing run of blanks is two clicks there with Select the rest, and the check has nothing to add.
The scan is also back to front, or sideways
Fix the order and the orientation first, in Reverse PDF pages or Rotate PDF, then clear the blanks. Working on a document you can read is how you notice that a page you were about to remove is not blank.
The document is a report rather than a scan
Look before you remove. Deliberate blank pages in a printed document are usually there to make chapters start on the right-hand side, and taking them out changes where every later chapter falls.
Why it marks pages instead of removing them
Nothing is taken out on its own, ever. The pages that look blank arrive selected so that the job left to you is looking rather than searching, and one page in particular needs looking at: a scanned page tinted a single even shade from edge to edge has nothing to be measured against, so that shade is read as its paper and the page is called blank. The same tint drawn by the app that made the PDF is shown as nearly blank instead. A very small pale mark can be missed for the same reason.
The other direction is safer by design. A page carrying only a page number, a footer or a running head is called nearly blank and arrives unselected, because removing it changes how the rest of the document reads. You can still select those yourself.
What removing a numbered page does
A page with a number printed on it is part of the document's numbering whether or not anything else is on it. Take it out and the printed numbers stop matching the pages, so page 14 of the file is page 15 of the document and anything referring to a page number is now wrong.
That is why those pages are left unselected rather than marked. If you do want them gone — and for a scan you usually do — take them out knowing the numbering is now decorative, or renumber the result with Add page numbers.
What to know before you start
- Nothing decides for you. The check marks candidates and the removal is yours to confirm, which is the only honest arrangement when a page can be blank to a measurement and meaningful to a reader.
- One document at a time, and a locked PDF is refused until its password is taken off with Unlock PDF.
- Your original is left exactly as it was. What you download is a new, shorter PDF.