How to use the Compress PDF
- 1
Choose a PDF.
- 2
Select a compression level. Strong compression lets you choose DPI and image quality.
- 3
Compress, check the new size and download.
Lossless vs strong compression
Lossless optimisation rewrites the file structure with compressed object streams and removes unused data. Text, links and vectors stay intact, but savings depend on the file. Strong compression re-renders each page as an optimised image at the DPI you choose. This dramatically shrinks scans and photo-heavy PDFs, but text is no longer selectable.
Picking a DPI
150 DPI keeps scanned text crisp on screen and in print at a fraction of the size. 100 DPI is fine for viewing on screen only. 200 DPI or more is best when small print must remain legible on paper.
Frequently asked questions
Is my PDF uploaded anywhere?
No. The PDF is opened and processed in your browser. It never leaves your device, which makes these tools safe for contracts, bank statements and medical records.
Does it work with password-protected PDFs?
PDFs that need a password to open cannot be processed. Open the file in your PDF reader with the password and save or print an unprotected copy first.
Why did my PDF hardly get smaller?
Text-only PDFs are already compact. Choose strong compression only if the file is mostly scanned pages or photos.