Compress PDF
Reduce PDF file size - strong image-based compression or lossless clean-up.
How to use
- Drop in your PDF.
- Pick a mode: Strong re-encodes pages as images (best for scans); Lossless keeps text selectable with modest savings.
- Compress, check the before/after size, and download.
Frequently asked questions
Which mode should I use?
For scanned documents and image-heavy PDFs, Strong mode saves the most. For text documents where you need selectable text, use Lossless.
Why is the compressed file barely smaller?
Lossless mode only removes structural bloat. If a PDF is already optimized, switch to Strong mode for real savings.
Is my document private?
Yes - compression runs entirely in your browser. Nothing is uploaded.
How PDF compression actually works
Most of a heavy PDF's size is images - scanned pages, embedded photos, logos saved at print resolution. This tool shrinks PDFs by re-encoding those images at a smarter quality level and resolution while leaving the text layer crisp, then rebuilding the file with tighter internal compression. Text-heavy PDFs shrink modestly (they were already efficient); scanned and image-heavy PDFs routinely drop 60-90%.
Everything happens in your browser. The document is parsed, recompressed and reassembled on your own device - nothing is uploaded, which is exactly what you want when the PDF is a signed contract or a passport scan.
Choosing the right compression level
Use the strongest setting when the goal is simply clearing an email attachment limit - the text stays perfectly readable and only fine photo detail softens. Use the balanced setting for documents that will be read on screen, and the light setting when the PDF contains photography that matters, like a portfolio or property listing.
A useful rule: if the PDF came from a scanner, compress hard - scanners default to absurdly high resolutions for documents that are ultimately read at screen size. If it came from a design tool, compress gently.
When compression won't help
A PDF that is pure digital text - an invoice generated by software, an ebook without images - is already close to its minimum size, and no compressor will meaningfully shrink it. If your file is still too large after compression, consider splitting it into parts with our Split PDF tool, or check whether a single enormous scanned page image is the culprit and rescan at 150-200 DPI, which is plenty for documents.