PDF Compressor
Shrink your PDF's file size by rebuilding its internal structure more efficiently — useful for emailing or uploading. All processing happens locally in your browser.
How to Use the PDF Compressor
- Choose a PDF file from your device.
- Click "Compress PDF" to rebuild the file with a leaner internal structure.
- Compare the original and compressed file sizes shown on screen.
- The optimized file downloads automatically.
Why Use This Tool?
Is my PDF uploaded to a server?
No. Compression runs entirely in your browser using the PDF-lib library — your file never leaves your device. This is important for sensitive documents like contracts or scanned IDs.
How does this compression actually work?
This tool re-saves the PDF using object streams, which de-duplicates and compactly encodes the document's internal objects (fonts, structure, metadata). It works best on PDFs with redundant internal structure, such as ones generated by certain editors or scanners, but it does not re-encode embedded images the way a dedicated image recompression tool would. For image-heavy PDFs, savings may be modest.
Will quality be affected?
No visible quality loss — text, images and layout remain unchanged. Only the file's internal packaging is optimized.
What if the compressed file isn't much smaller?
Some PDFs are already efficiently packaged, especially simple text-only documents, so compression gains can vary widely from file to file.