Why pages end up sideways
Scanners and phone scanning apps don’t always know which way up you fed the paper, and a landscape page saved from a presentation or spreadsheet can arrive turned onto its side. Most of the time the file is fine: the content is all there, it’s just being shown at the wrong angle, and the only thing wrong is which way the page is turned.
What rotating actually changes
Every page in a PDF has a rotation setting (0°, 90°, 180° or 270°) that a PDF viewer applies when it draws the page. Rotating a page here changes that one setting and nothing else. The drawing instructions, the fonts and the images stay exactly as they were, which is why the result is lossless and why the file size barely moves. It also means PDF viewers pick the new orientation up straight away when they open the copy you download.
Turning one page, or many
Each page shows as a small preview with its own buttons, so a mostly upright scan with a few sideways pages takes a few clicks. The preview turns as you click, so you see the result before you download. To turn every page by the same amount, or a set of pages by number (4, 2-5, or a list like 1-3, 7), use “Turn many pages”. Listing a page twice doesn’t turn it twice.
Spotting sideways pages
When the file opens, the tool reads which way the text on each page runs. Pages whose text runs sideways or upside down are marked, and one click turns them all the right way up. If a page is meant to be sideways, a wide table for instance, press “Leave as is”. A page with no text layer, which is how many scans are saved, can’t be read this way, so it’s never marked.
Password-protected files
A PDF with an open password asks for it first. The password is used only in this tab, to open the file and to lock the copy you download, which opens with the same password. Files that open without a password but restrict printing or editing, like many bank statements, open straight away, and the copy keeps the same restrictions.
What this tool doesn’t do
It turns pages in steps of 90°: it won’t straighten a scan that was fed in a few degrees crooked, and it doesn’t crop or resize. It changes how pages are turned, not where they sit in the document: putting pages in a different order, or dropping some, is a separate job.