This Bash script compresses PDF files using Ghostscript, with three levels of quality to choose from.
It’s ideal for reducing file sizes while maintaining decent readability and quality — perfect for archiving, emailing, or uploading documents.

• Compress any .pdf file directly from the terminal
• Choose between 3 compression levels
• Displays compression progress with readable and colorized output
• Prevents overwriting: auto-increments output filenames
• Works seamlessly with macOS and Linux

• Ghostscript (must be installed)

To install it:

# macOS (with Homebrew)
brew install ghostscript

# Ubuntu/Debian
sudo apt install ghostscript

compress /path/to/file.pdf [quality]

• file.pdf: Required – the path to the PDF file to compress
• quality: Optional – choose a value between 1, 2, or 3
  • 1 – Less compression, High quality (downsampling images)
  • 2 – Recommended compression, Good quality (default)
  • 3 – Extreme compression, Lower quality

💡 If no quality is given or an invalid value is entered, it defaults to 2.

compress ~/Documents/Report.pdf 2

Output:

⏳ Starting compression of "Report.pdf" with quality setting: 2 (Recommended compression, Good quality)...
✅ Compressed file: Report_compressed.pdf | Original size: 6.3M | Compressed size: 452K

You can create an alias to use compress from anywhere in your terminal:

1. Open your .zshrc:

nano ~/.zshrc

2. Add the following line (update the path if needed):

alias compress="/full/path/to/your/script.sh"

For example:

alias compress="/Users/yourname/scripts/pdf_compress.sh"

3. Save and reload your terminal:

source ~/.zshrc

Then just run:

compress myfile.pdf 2

The compressed file is saved in the same folder as the original, with _compressed.pdf (or _compressed_2.pdf, etc.) appended to the filename.

MIT License – do whatever you want, just give credit if you reuse parts of the code.