Compress PDF
Shrink image-heavy PDFs for email and uploads. Fully offline-capable.
100% Browser-Based — Files Never Leave Your Device
About Compress PDF
Most of a PDF’s size usually comes from photos and scanned pages. This tool re-encodes those images at a lower quality and resolution while leaving text and vector graphics untouched, so documents stay crisp and searchable. Choose a level, or use one of the exact-size tools if you need to hit a specific limit.
How to compress PDF
- Choose the PDF you want to make smaller.
- Pick a compression level.
- Click "Compress PDF" and download the smaller file.
Frequently asked questions
Is it safe to compress PDFs here? Are my files uploaded?
Nothing is uploaded. PDFToolsFast runs entirely in your browser using JavaScript and Web Workers, so your files stay on your device. You can even disconnect from the internet after the page loads and the tool keeps working.
How much smaller will my PDF get?
Scanned and photo-heavy PDFs often shrink by 50–90%. Text-only PDFs are already compact and may barely change.
Will my text stay selectable?
Yes. Only embedded images are recompressed; text and vector graphics are untouched.
How do I shrink a scanned document the most?
Choose “Black & white” under Document type. It turns scanned pages into crisp 1-bit images that are often several times smaller than color, while keeping text sharp. “Grayscale” suits scans with photos or pencil marks.
I need my PDF under a specific size. What should I use?
Use Compress PDF to 100KB, 200KB or 500KB. They automatically search for the best quality that fits strictly under the limit.
Is it really free? Are there limits or watermarks?
Yes, it is free with no sign-up, no daily task limit and no watermark. Because your own device does the work, we have no per-file server costs to pass on.