How to Reorder and Delete PDF Pages

Reordering pages in a PDF: the order is given in full

An annex ended up before the body text, the title sheet slid into the middle, a double-sided scan interleaved fronts with backs. The task is clear: put the pages in the right order. The tool does that, but it takes its instruction in a form that explains most surprising results.

The order is a complete list, not a list of moves

The main thing to grasp before you start. You do not say "move page five to the front", you give the complete sequence of pages in the finished document.

Hence a consequence that costs documents. A page missing from the list will not reach the result. Not because the tool decided to throw it away, but because you described a document that does not contain it.

In a forty-page document where pages two and three have to swap, the order reads `1,3,2,4,5,6` and on to forty. Writing only `1,3,2` asks for a three-page document.

The practical conclusion: before running, compare the length of your list against the page count. If they differ, that is either a deliberate decision or a mistake, and only the number tells them apart.

A side effect, and a useful one: reordering can also delete. If you need the first thirty of forty pages in a different order and the last ten not at all, one operation does everything.

Duplicates are dropped until you allow them

The second parameter governs what happens to repeats in the list.

By default the duplication switch is off, and a repeated number is silently dropped: the page reaches the result once, at its first mention. That is a guard against a typo which would otherwise turn a document into a stack of repeats.

Turning duplication on inverts the behaviour: a number may repeat as often as you like, and every mention yields a page in the result.

What it is for. Separator sheets that must sit between sections. A form repeated once per copy. A terms page that regulations require attached to every annex. In each case the source holds one copy and the result needs several.

This is the only tool that increases the page count without a second file being added.

How to reorder the pages

1. Open organize-pdf and upload the document. 2. Wait for the preview grid: the order is set from the pictures rather than from numbers you remember. 3. Arrange the pages into the sequence you want. 4. Turn duplication on if some page has to repeat. 5. Run the job and page through the whole result.

Do point five by paging through rather than sampling. A mistake in the order almost always shows up where two sections join, not at the start of the document.

How the sequence is written

The notation is the same as in the other page-level tools: numbers separated by commas, with consecutive ones collapsed into an interval joined by a hyphen.

Writing `1,5-8,2-4,9` describes a nine-page document in which page one is followed by the block from five to eight, then the block from two to four, then page nine. That is the typical shape for a document whose annex ended up in the wrong place.

The rules are strict and identical everywhere. Numbering starts at one. An interval cannot start after it ends. A number outside the document produces an error rather than being ignored.

That last one is most noticeable here. In the other tools the numbers are usually ticked with a mouse, whereas an order is more often typed, and a typo in a figure is more common. The job will not run partially: it stops outright, which beats a document in which one page went missing unnoticed.

Bookmarks follow their pages

Bookmarks are not lost in a reorder. Each is recomputed to its page's new position, and navigating by the contents keeps working.

The structure of the contents then reflects the document's new order rather than the original. Swap two sections and they swap in the bookmarks panel too.

The document properties, title, author and keywords, carry over unchanged.

Pages that missed the list take their bookmarks with them. If your reorder also discarded half the document, the contents will be half as long, and that is expected.

Automatic compaction after the reorder

A separate switch, on by default, runs an additional compaction of the page content after reordering.

The effect is small and benign: the file comes out slightly more compact than the source thanks to denser packing of its internal streams. It does not touch the content, the image quality or the text layer in any way.

There is one reason to switch it off: the document goes into a procedure where byte-level comparability with the source matters. In every other situation it stays on and nobody thinks about it.

It is not a substitute for real size reduction: that needs the compression tool, which works on images.

When a different tool fits better

Three neighbouring jobs that are not solved here.

Removing a few pages without touching the order of the rest. Reordering can formally do it, but writing a list of thirty-seven numbers to delete three pages is pointless: remove-pages does the same with three ticks.

Assembling a new document from a few pages of a large one. That too is possible by reordering, but extract-pages expresses the intent more precisely and offers a mode producing one file per page.

Standing pages the right way up. Reordering changes the order but not the orientation: a rotated page stays rotated in its new place. That is work for rotate-pdf, and it is easier done before the reorder, while the preview still shows readable content.

The ceiling on output pages

With duplication on, the length of the list is not bounded by the source at all: one page can repeat any number of times.

Hence a ceiling: the result cannot exceed ten thousand pages. Beyond that the job stops and reports the requested number alongside the permitted one.

In practice that limit is only reached through a typo in a range, so the message is best read as a prompt to check the notation rather than as a limit on what you can do.

Typical jobs and how they look as a list

A double-sided scan without duplex. All the fronts come first, then all the backs. The order is restored by interleaving: page one, then the first page of the second half, then page two, and so on.

An annex that ended up before the body text. The list begins with the body-text range and ends with the annex range.

A title sheet that arrived from another file and landed at the end. Its number goes first and the rest follow in sequence.

In all three cases it helps to assemble the document in full with merge-pdf first and fix the order in one operation at the end: fewer intermediate files, and fewer chances of losing a page between steps.