About this tool
PDF size is usually image size. Scanned pages are stored as large pictures, so the only way to shrink them meaningfully is to re-encode those pictures at a lower resolution and quality.
This tool renders each page at the resolution you choose, encodes it as JPEG, and rebuilds the PDF from those images. The result opens everywhere and can be dramatically smaller, but the text is no longer selectable.
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 Compare the size shown against the original, then download if the trade-off works for you.
Good to know
- This is lossy compression: text becomes an image and cannot be searched or selected afterwards.
- If the result is larger than the original, keep the original — the file was already efficient.
Frequently asked questions
Why is compression lossy?
Browsers cannot re-encode embedded PDF fonts and images the way a desktop tool can. Re-rendering pages is the reliable approach that works for every file, and it always trades quality for size.
How much smaller will my file get?
Scanned documents often shrink by 50–90%. Text-heavy PDFs produced by Word or LaTeX are already compact and may shrink very little — or grow. The tool shows the before and after size so you can decide.
Will links and forms still work?
No. Because pages are rebuilt as images, links, form fields and bookmarks are not carried over. Use compression for reading copies, not for interactive documents.