You rotate a PDF page in your viewer. It looks correct on screen. You close the file, reopen it — the page is sideways again.

This happens because most PDF viewers (including browser PDF viewers) apply rotation as a display preference, not a change to the actual file. The rotation isn't saved into the PDF — it's just how your viewer renders it.

The fix: rotate and re-save the PDF itself, not just the view.

Permanently rotate a PDF: PDF Rotate Tool — Fix and Save Page Orientation

Why PDF Rotation Keeps Resetting

PDF files store page rotation as metadata in the file structure. When you rotate a page in Adobe Reader, Chrome's PDF viewer, or most preview apps, they update a local display setting — not the file.…