How to fix a sideways or upside-down scanned PDF

Viewing rotated is not the same as being rotated

Almost every PDF reader has a rotate-view button. It turns the page on your screen and does nothing to the document. Close the file and it is sideways again; email it and the recipient sees it sideways too.

What you need is a rotation written into the file, so the page's orientation travels with it. That is what this tool does, and it is why the result opens correctly everywhere — in a browser, in Acrobat, on a phone, and on paper.

If you rotated in your reader and the file still looks wrong to other people, this is why.

Rotating the pages

Rotation happens in 90-degree steps, which is all a PDF page supports. Correcting a page that is scanned at a slight angle is a different problem, and not one any PDF tool can solve; that needs rescanning or a de-skew feature in your scanner software.

1. 1Open the Rotate PDF tool and choose your file.
2. 2Use the rotate-all buttons if every page is wrong in the same direction.
3. 3Or click the rotate control on individual thumbnails for the pages that need it.
4. 4Check the preview — what you see is what the file will contain — then download.

Why scans come out rotated in the first place

Automatic orientation detection is the most common culprit. Scanner software guesses which way is up by looking for text, so a page that is mostly a table, a drawing or a photograph gives it very little to go on — and it guesses wrong about as often as it guesses right.

Whole document or individual pages?

If every page is wrong in the same direction, rotate everything at once. It is one click and there is nothing to check afterwards beyond a glance at the preview.

If the document is mixed — say a report where the landscape charts are sideways but the text pages are fine — rotate those pages individually. Rotating everything and then rotating half of it back is a reliable way to end up with a document that is wrong in a new way.

For a document that also needs pages reordered or removed, do all of it in the Organize tool instead, where rotation, reordering and deletion happen in a single pass.

It does not affect quality

Rotation is recorded as a property of the page, not as a redrawing of its contents. Nothing is re-rendered and nothing is re-compressed, so text stays crisp, images keep their exact original pixels, and the file size barely changes.

This also means rotating is completely reversible. Rotate the wrong way and you can simply rotate back with no accumulated loss, unlike an image editor where every save costs a little quality.

Rotation and printing

A correctly rotated PDF prints correctly with no special settings. If a page is landscape, most printers detect that and either rotate the content to fit or ask you to choose an orientation.

Where people run into trouble is printing a document whose rotation was never saved — the printer receives the original orientation, not what you were looking at on screen. Save the rotation first and the print dialog stops being a guessing game.

Fixing scans properly, in order

1. 1Rotate the pages so everything is the right way up.
2. 2Remove blank pages if you scanned double-sided originals that were printed on one side.
3. 3Crop away scanner margins and black edges if there are any.
4. 4Run OCR if you want the text to be searchable.
5. 5Compress last, once the document contains only the pages you are keeping.

Compressing last is the part people get backwards. Optimising pages you are about to delete or crop is wasted effort, and each processing pass on an image costs a little quality.