How much can a PDF be compressed?

Depends on content. PDFs with large images can often be reduced by 50-80%. Text-only PDFs are already highly compressed and may only reduce by 10-20%. Scanned document PDFs can often be reduced significantly.

What does PDF compression actually do?

It reduces image resolution/quality within the PDF, removes duplicate image data, applies more aggressive stream compression, strips unnecessary metadata, and removes embedded fonts if possible.

Will compressed PDFs print at lower quality?

At "Balanced" compression level, print quality is preserved for most documents. "Maximum compression" may reduce image sharpness. For archival/print PDFs, use "Minimum compression".

Can I compress a password-protected PDF?

No. Remove the password protection first, compress, then re-add password protection if needed.

What is the maximum PDF file size?

The tool handles PDFs up to 100MB. Very large PDFs (50MB+) may take longer to process depending on your device.

ToolsArena

PDF Compressor

Compress PDF files to reduce size while maintaining quality online.

Browser-based PDF optimization: This tool optimizes the PDF structure by removing unused objects and compressing internal streams. For image-heavy PDFs or maximum compression, use a desktop tool like Adobe Acrobat or Smallpdf.

Click to upload or drag and drop

PDF file only — max 100MB

How to Use PDF Compressor

1
Upload the PDF file you want to compress.
2
Choose compression level: Maximum Quality, Balanced, or Maximum Compression.
3
Click "Compress PDF" and wait for processing.
4
View the compression results: original vs compressed size.
5
Download the compressed PDF.

About PDF Compressor

Reduce the file size of your PDF documents while maintaining acceptable quality with our free PDF Compressor. Smaller PDFs are faster to email, upload, and share — and many email clients and websites have file size limits that this tool helps you meet.

The compressor optimizes embedded images, removes redundant data streams, and applies lossless optimizations to the PDF structure. You can choose compression levels: maximum quality (slight reduction), balanced (good quality, smaller size), or maximum compression (smallest size, reduced image quality).

All compression happens client-side using pdf-lib — your sensitive documents never reach our servers. No watermarks are added. The tool shows you the compressed file size before you download.