PDF Compressor Test Results: How Much Size You Actually Save

On 17 October 2026 we built an 8-page A4 text PDF with pdf-lib, saved it without object streams (16,422 bytes), then rebuilt it with object streams (8,632 bytes). That is a 47.4% cut. Those PDF compressor test results describe this document, not every PDF on your disk.

What the Toolstik compressor actually does

The PDF Compressor reloads the file in your browser and writes it again with useObjectStreams: true. It does not downsample JPEGs on each page. That is why a scan of a contract often shows “already optimized” while a verbose export from a word processor can drop a lot of unused objects.

How to test your own file

1. Open the PDF Compressor and drop the file (up to 50 MB).
2. Read the before/after sizes. If there is no saving, do not download.
3. If you still need a smaller attachment, convert pages to images with PDF to JPG or extract the pages you actually need with the PDF Splitter.

PDF compression vs conversion explains when shrinking in-place is the wrong job. How to compress a PDF walks through the buttons.

Cite this page as a dated lab note, then measure the file you actually need to send.