Organize PDF

Every PDF page carries a rotation value — 0, 90, 180 or 270 degrees — that tells a viewer which way up to draw it. The page content underneath never moves. Correcting a sideways scan therefore changes one number and nothing else: no pixels are resampled, no text is re-laid out, the file size does not shift, and you can rotate back and forth all day without any loss.

This is why rotating here is different from rotating in a PDF reader. Most viewers offer a rotate button that turns your screen and leaves the file alone, so the document you email is still sideways for the recipient. Saving the rotation into the document is what actually fixes it, for everyone, permanently.

Mixed orientations are normal and worth keeping. A report with a landscape table in the middle of portrait pages should stay that way — rotating everything to match would turn the table on its side. Per-page rotation exists precisely so you can fix the three pages your scanner fed in backwards without touching the rest.

Scanners produce out-of-order documents with impressive reliability. A duplex scanner fed a single-sided stack interleaves blanks between every page. A sheet feeder taking the pile face-up delivers the whole document backwards. Scanning in two passes gets you all the odd pages followed by all the even ones, which is the most tedious of the three to untangle by hand.

The thumbnail grid is the fastest way through all of them, because you can see what you are fixing. Drag a page to its correct slot and the positions renumber immediately. Reversing the whole document is one action rather than dozens. The two-pass case is the one worth being deliberate about: interleave rather than drag, and check the join at the start and end before saving.

It is also worth doing this before anything else. Reordering after you have added page numbers means the numbers are now wrong, and reordering after adding bookmarks means the bookmarks point at the wrong pages.

Reordering and rotating operate on the document's list of pages, not on their content. Each page object is the same object it was, carrying the same text, fonts, vector artwork and images — nothing is re-rendered, re-encoded or re-compressed. A page that was crisp before is byte-for-byte as crisp afterwards, however many times you move it.

Links inside a page keep working. What can break is anything that referred to a page by its position: bookmarks pointing at a page that is now elsewhere, cross-references written as literal page numbers, and printed page numbers stamped onto the pages themselves. None of those can be repaired automatically without guessing, so they are deliberately left alone.

The practical order of operations, then, is: organise first, then number, then bookmark, then protect. Doing it the other way round means redoing the later steps.

Organising covers reordering, rotating and dropping pages from one document. Several neighbouring jobs have dedicated tools that do them better. Removing a long list of pages by number or by pattern — every other page, everything blank — is what Delete Pages is for, including a scanner for blank pages that a duplex pass has left behind.

Pulling a chapter out into its own file is Extract Pages, which can also save each selected page as a separate document. Adding pages from elsewhere is Insert Pages, and combining whole documents is Merge PDF.

If what you actually want is fewer sheets of paper rather than a different order, N-up PDF places two or four pages on each sheet, and Resize PDF changes the paper size the pages are laid out on.