Feed a stack of paper into a scanner and you often get a PDF where half the pages are sideways, two are upside down and one is a blank back. It is annoying, but every one of those problems has a quick fix, and you do not need to rescan anything. The key is to repair the file in the right order.
Why scans end up sideways
Document feeders pull sheets in a fixed direction, so a landscape page fed in the wrong way arrives sideways. Mixed stacks of portrait and landscape sheets make it worse. Phone scanners decide orientation from how you held the phone. Even a perfectly good scan can open sideways in one program and upright in another, because some store a hidden rotation tag.
Rotate pages for good
PDF viewers have a rotate-view button, but the page springs back next time you open the file, and other people will still see it sideways. To make the fix stick, use Rotate PDF. Click the rotate button on each wrong page, or rotate everything at once with the buttons on top, then save. The new orientation is stored in the file, so it shows correctly in every viewer.
Rotating does not re-render the page, so quality is unchanged.
Put pages in order and drop the blanks
In Organize PDF you see all pages as thumbnails. Drag to reorder, press the delete button on blank backs, and use "Reverse order" if the stack went through back to front. Nothing changes until you save, and you can restore deleted pages while you work. If you only need to delete, Remove Pages with its odd and even selectors is faster. Our guide to deleting pages has the details.
Trim scanner borders
Scanners often leave grey shadows or wide white margins. Crop PDF lets you enter millimetres for each side and shows a shaded preview of what disappears. Start with small values like 5 to 10 mm. The same crop applies to every page, so check the page with the widest content first.
Be aware of two limits. Crop trims the visible area equally on all pages, so it will not straighten pages that were fed in at a slight angle. And it hides what is outside the new edges rather than deleting it, so do not use it to remove sensitive information.
Mixed orientations in one file
It is normal to have some landscape pages in a portrait document, for instance a wide table. Make sure the page is rotated so the text reads upright when you view it, and leave it landscape. Rotating a wide table to portrait just to match the others makes it harder to read.
Scan better next time
- Align the paper against the guide to avoid skewed pages.
- Scan at 300 DPI for text, and use black and white or grayscale for plain documents. Color makes files huge. See best scan settings.
- Feed pages in the same direction every time, and keep landscape sheets in a separate batch.
- Check the first two pages before scanning a long stack.
Finish with a smaller file
Once the pages look right, the file may still be heavy. Shrink it with Compress PDF before you share it. Compress last, so you only reduce image quality once.
