BASALT · JOURNAL
How to rotate PDF pages on a Mac and make it stick
Rotation is simple until it silently does not persist, which is the complaint that brings most people to search for it.
In Preview
Open the document, show thumbnails, select the pages, and press Command with the left or right bracket. Or use Tools, Rotate.
Then save with Command S. The saving step is where it goes wrong.
Why rotation sometimes does not stick
Two common causes.
The document was opened from a location you do not have write access to, such as a mounted volume or a downloads location managed by another application. Preview appears to accept the rotation and the save fails quietly or writes elsewhere.
Or the viewer you check it in ignores the page rotation attribute. Rotation in a PDF is metadata on the page rather than a transformation of the content, and a small number of tools and printers disregard it. If a document looks correct on screen and prints sideways, this is why.
Rotating everything at once
qpdf rotates without re-rendering:
qpdf input.pdf --rotate=+90 -- output.pdfAdd a page range to be selective, for example --rotate=+90:2-10.
Positive numbers rotate clockwise. The value is applied relative to the current rotation, so running it twice gives 180 degrees.
Rotation and scanned documents
A scan that came in upside down often has a page rotation applied by the scanner rather than the image itself being the right way up. Both look identical on screen. The difference appears when the document is processed by something that flattens or re-renders it.
If rotation keeps reverting through a workflow, the safest fix is to bake it in by re-rendering the page rather than setting the attribute, accepting that this makes the page an image.
Frequently asked questions
How do I rotate a PDF on Mac?
In Preview, show thumbnails, select the pages, and press Command with the left or right bracket, then save with Command S. For a whole document at once, qpdf input.pdf --rotate=+90 -- output.pdf.
Why does my PDF rotation not save?
Usually because the file is in a location you cannot write to, so the save fails quietly. Occasionally because the viewer you are checking in ignores the page rotation attribute, which is metadata rather than a change to the content.
Why does my PDF print sideways when it looks correct on screen?
Because rotation is stored as an attribute on the page and some printers and tools disregard it. Re-rendering the page bakes the orientation into the content, at the cost of turning it into an image.
How do I rotate only some pages?
With qpdf, add a range to the rotate option: qpdf input.pdf --rotate=+90:2-10 -- output.pdf rotates pages 2 to 10 only.
Doing it in Basalt
Basalt is a native macOS PDF toolkit: eighteen tools in one window covering merge, split, page organisation, compression, OCR, passwords, Bates numbering, forms, signing, watermarks and comparison. Every file is processed on your Mac, and the engine that opens documents holds no network entitlement at all, which macOS enforces at the code-signature level. Redaction destroys content rather than covering it, and an independent verifier proves the material is gone before a file is written. A one time $29 licence covers up to three Macs, free for the first 24 hours. Get it at basaltformac.com, or brew install --cask chipmunk1101/tap/basalt.
Redaction that proves itself
Basalt destroys the content you mark, then re-opens the file it wrote and proves the content is gone before it saves anything. Your documents never leave your Mac.