Most PDF size lives in images, and re-encoding images is something a browser cannot do without decoding and redrawing every one of them - which is where quality quietly goes. So this tool does the honest half of the job: it rebuilds the file with a cleaner internal structure and removes metadata, and it tells you plainly when there was nothing left to gain.

Using it in three steps

1. 1 Drop the PDF you want to slim down.
2. 2 Press Optimise. There are no quality settings, because nothing here touches the quality.
3. 3 Read the size shown before and after, then download only if the saving is worth it.

Metadata worth removing

The saving in bytes is small, but the saving in awkwardness sometimes is not. A PDF quietly carries the author name, the software that made it, and creation and modification dates - which means a document written for one client can announce that it was drafted for another the week before. Clearing that out is the part of this tool that most reliably does something you actually wanted.

When the size does not move

If the result is the same size, the file was already tidy and the weight is in its images. The tool says so rather than handing you an identical file and calling it compressed. The real fix in that case is upstream: scan at 200 or 300 dpi instead of 600, or shrink the photographs before they go into the PDF. Nothing done to the finished document can undo a scan that was made three times larger than it needed to be.