What this does

This turns the pages of a PDF and saves the result — every page at once, one page at a time, or only the ones that are lying on their side. The file is edited in your browser and never uploaded.

Finding the sideways pages for you

Turning a PDF is easy. Working out which pages need it is the tedious part, and on a scanned document — where some sheets went through the feeder the wrong way round — it is the whole job.

A page carries no flag saying “this one is wrong”. What it carries is text, and text is drawn along a direction: every run of glyphs in a PDF has a matrix, and the first two numbers of that matrix are the direction its baseline runs in. Upright text runs across the page; text on a sheet fed in sideways runs up or down it. So this reads the direction of every run, weighs them by how much text each one carries, and tells you which pages are lying down.

It is deliberately cautious. A sideways caption can't outvote the body it sits beside, a diagonal watermark doesn't get a say at all, and a page whose text is genuinely mixed is reported as unknown rather than guessed at. A page with no text — a photograph, or a scan that has never been through OCR — is left alone, because there is nothing in it to read.

Why not just use Organize PDF?

Organize PDF can turn pages too, alongside reordering, duplicating and deleting them. Use it when you're doing several of those things at once.

This tool exists for the case where turning is all you want, and it does one thing differently because of that. Reordering a document means rebuilding it, and a rebuilt PDF is assembled page by page: the pages arrive whole, with their fonts and images, but the document's own furniture — bookmarks, the outline, form field definitions — is left behind. Turning a page changes one number on that page, so here the file is edited in place and all of that survives.

How to use it

Drop in a PDF.
If some pages are sideways you'll be told how many, and one button straightens exactly those.
Otherwise turn everything with the buttons at the top, or turn single pages on their tiles.
Save, and download.

Things worth knowing

Turns add up. A page that was already sideways in the original and is turned a quarter more ends up a quarter further round — not reset to upright. That's what turning a page has to mean.
Nothing is re-rendered. Rotation is a number on the page, not a redraw, so text stays selectable and artwork stays sharp. The file barely changes size.
Quarter turns only. PDF only defines page rotation in multiples of 90°, so there's no way to nudge a crooked scan by two degrees. That would need the page re-drawn, which is a different operation on a different kind of file.
A scan with no text can't be read. If the pages are photographs, there are no glyph matrices to look at and nothing to detect. Turn them by hand, or run the file throughOCR first and come back.

Frequently asked questions

Is my file uploaded?

No. It's read and edited in your browser. You can watch the network panel while it runs, or disconnect from the internet once the page has loaded and rotate anyway — it still works.

Why does it say it can't tell which way up a page is?

Either the page has no text on it, or the text it has runs in more than one direction with no clear majority. Both are honest answers, and both mean you should look at the page and decide yourself rather than have the tool guess.

Will the rotation stick when I print it?

Yes. Page rotation is part of the file, not a viewing preference, so every reader and printer sees the same thing.

Can I straighten a scan that's a few degrees crooked?

Not here. PDF page rotation only comes in quarter turns; anything finer means re-drawing the page as an image, which loses the text.