Crop · nothing uploaded
Trim wide margins so the text fills a tablet or e-reader screen, or cut off the dark edge a scanner left behind. Live preview, and nothing leaves this tab.
Cropped on your own machine — nothing was uploaded. Kagaz is free and open source, made by Amit Jena in India.
This is the one thing worth understanding. A PDF page has a visible area — the crop box — and changing it is like putting a mask over the page. Everything outside the mask is still inside the file, and anyone can bring it back by widening the crop.
So cropping is perfect for tidying margins and useless for hiding anything. If there is something on the page that must not be seen, use Redact PDF, which removes the underlying content for real.
Because a document can mix page sizes, and "trim 20 mm" means something different on A5 and A3. A percentage of each page's own width does the sensible thing everywhere.
No. The preview is rendered in your browser and so is the cropped file. There is no server.
No. Cropping does not scale anything. The page becomes smaller, so when a reader fits it to your screen the text ends up looking larger — which is usually the point.
One crop is applied to every selected page. Per-page cropping is a good first issue.