Why does the rotation keep reverting?
This is the question that brings most people here, and the answer is that there are two different kinds of rotation.
Your PDF reader almost certainly has a rotate button. In many readers that button rotates the view — it changes what you see on screen and discards the change when you close the file. Send the document to someone else and it arrives sideways again.
This page rotates the document. The angle is written into each page’s own properties, so it is part of the file. It opens correctly for you, for the person you send it to, and for whatever software they happen to use.
Which angle do I need?
- 90 — a page that needs turning clockwise. The common case for a scan fed in sideways.
- 180 — a page that is upside down.
- 270 — 90 degrees anticlockwise.
Nothing is re-rendered
Rotation changes a property, not pixels. No page is re-drawn, no image is re-encoded, no text is rasterised.
That means quality is completely untouched and the file size barely moves — you get the same document, oriented correctly.
Rotating only some pages
This page applies the rotation to the whole document, which covers the usual case of a scan that came in the wrong way round.
For a mixed document, the route is: extract the pages that need turning, rotate them here, then merge everything back together in order.
Why do it locally
Scans that need rotating are, overwhelmingly, scans of paperwork — forms, contracts, identity documents, letters.
Nothing is transmitted here. The Uploaded readout beside the result measures this page’s own outbound network calls directly, and reads 0 B on a successful rotation.
Questions
- Why does my PDF go back to being sideways when I reopen it?
- Because your reader rotated the view rather than the document. Many PDF viewers offer a rotate button that changes only how the file is displayed on your screen, and discards that when you close it. This page writes the rotation into each page's own properties, so it travels with the file.
- How do I rotate a PDF permanently?
- Add it here, choose the angle, and download the result. The new file carries the rotation in the document itself, which means it opens correctly for whoever you send it to — not just for you.
- Which direction is 90 degrees?
- Clockwise. Use 270 for 90 degrees anticlockwise, and 180 for a document that is upside down.
- Can I rotate only some pages?
- This page applies the rotation to the whole document. To rotate a subset, extract those pages first, rotate them, and merge the result back together.
- Does rotating reduce quality?
- No. Rotation changes a page property; it does not re-render or re-compress anything. Images are not re-encoded and text is not rasterised.
- Is my document uploaded?
- No. The rotation happens in this browser tab with pdf-lib. The Uploaded readout beside the result measures the page's own outbound traffic, so a successful rotation reads 0 B.
- Will the file size change?
- Barely. Only a page property is altered, so the file stays essentially the same size.
- Will there be a watermark?
- No. Nothing is added to the pages and nothing is held behind a paid tier.
- Are password-protected PDFs supported?
- Documents that only restrict editing will usually work. Documents that require a password to open cannot be read without it. Remove the password in your reader first.
- Is there a page limit?
- None imposed. Your device's memory is the only ceiling.