Optimise PDF Size
Most oversized PDFs are large because of the images inside them, not because of the document structure. That is why a PDF that is mostly text often cannot be shrunk much, while a scanned document can lose most of its size.
Compress PDF offers a structural pass that keeps text selectable, and stronger modes that redraw pages as images at a lower resolution and JPEG quality. The stronger modes produce much smaller files and remove the text layer, which is a real trade-off and is stated before you run it. The size shown after processing is the true size of the file you are about to download, including when it turns out to be no smaller.
Tools in Optimise PDF Size
Frequently asked questions
Why did my file get no smaller?
A text-heavy PDF that was generated cleanly has very little slack in it. The structural pass can only remove redundancy in the file's internal objects, and there may not be any. In that case the tool tells you so and offers the original file rather than a larger one.
Will compression blur my document?
The structural mode changes nothing visually. The rasterising modes re-encode pages as JPEG images, so quality loss is possible and text becomes an image.
Guides
- Why PDF compression sometimes does nothing — What actually occupies space in a PDF, which files can shrink, and the trade-off you accept when pages are rasterised.