About this tool
PDF size is usually image size. Scanned pages are stored as large pictures, so the way to shrink them meaningfully is to re-encode those pictures at a lower resolution and quality.
This tool tries two routes and keeps whichever produces the smaller file. A lossless rewrite keeps the document exactly as it was — text selectable, links working. Re-encoding pages as images goes much further on scans, but the text becomes a picture.
How to compress PDF
- 1 Add the PDF and pick a compression level: Smallest, Balanced, or High quality.
- 2 Run the compression and watch the page counter — large scans take a few seconds per page.
- 3 The result states which route won and how much was saved, then you can download or keep the original.
Good to know
- Both routes run; the smaller result is the one you get, and the lossless rewrite is preferred whenever the sizes tie.
- If neither route beats the original size, the tool says so and leaves your file untouched rather than returning something larger.
Frequently asked questions
Does compression always make the text unselectable?
No. That only happens when the image route wins, which is typical for scans. For text PDFs the lossless rewrite usually wins, and the text, links and bookmarks stay intact. The result panel names the route that was used.
How much smaller will my file get?
Scanned documents often shrink by 50–90% at the Smallest level. Text-heavy PDFs produced by Word or LaTeX are already compact and often shrink only slightly, or not at all — in which case nothing is returned and you keep the original.
Will links and forms still work?
Only if the lossless rewrite won. When pages are rebuilt as images, links, form fields and bookmarks are not carried over, so use that result for reading copies rather than interactive documents. The result panel tells you which one you have.