In our Linux system, If we have a large PDF file, we may want to reduce it’s size. We shall look at different ways to reduce PDF size or compress PDF files in Linux in this tutorial.
Let’s find out some Command Line and GUI methods to deal with this problem.
Table of Contents
Command Line Utilities to Reduce PDF File Size in Linux
1. Using GhostScript
We can use the ghostscript
command line utility in Linux to compress PDFs.
If the command is not available in your machine, you can install it using your package manager.
For example, in Ubuntu, you can use apt
:
sudo apt install ghostscript
You can use this magic command to compress PDFs to a readable quality.
gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/screen -dNOPAUSE -dQUIET -dBATCH -sOutputFile=output.pdf input.pdf
Here, replace output.pdf
and input.pdf
accordingly.
The various tweaks to the -dPDFSETTINGS
option are provided in the table below. Use them according to your need.
-dPDFSETTINGS Option | Description |
-dPDFSETTINGS=/screen | Has a lower quality and smaller size. (72 dpi) |
-dPDFSETTINGS=/ebook | Has a better quality, but has a slightly larger size (150 dpi) |
-dPDFSETTINGS=/prepress | Output is of a higher size and quality (300 dpi) |
-dPDFSETTINGS=/printer | Output is of a printer type quality (300 dpi) |
-dPDFSETTINGS=/default | Selects the output which is useful for multiple purposes. Can cause large PDFS. |
I have used the above command to achieve a compression from 73MB to 14MB!

2. Use ps2pdf
This command ps2pdf
converts a PDF to PS and then again back, compressing it efficiently as a result.
It may not always work, but it can give very good results.
Format:
ps2pdf input.pdf output.pdf
It is recommended that you use the -dPDFSETTINGS=/ebooks
setting to get the best performance, as ebooks have the best size for readability and also are small enough in size.
ps2pdf -dPDFSETTINGS=/ebook input.pdf output.pdf
I have tried this on a 73MB PDF and it had the same results as the ghostscript
command, the compressed PDF having only 14MB!

GUI Utilities to Reduce PDF File Size in Linux
If you are uncomfortable with using command line tools, there is a GUI alternative as well.
Densify
This is a GUI front end to ghostscript
, which can be installed in any Linux distribution, since it uses Python3
and it’s GTK
modules.
This package is called Densify, and is available here(Link to github).
I have created a simple bash
script to do all the necessary work. Run this bash script as root, to link and download necessary files.
#!/bin/bash #- HELPER SCRIPT FOR DENSIFY #- original package https://github.com/hkdb/Densify #- script author Vijay Ramachandran #- site https://journaldev.com #- # Go to your home directory (preferred) cd $HOME # Download the package git clone https://github.com/hkdb/Densify cd Densify # Queue must be changed to queue in the file. # Will not work otherwise sed -i 's/Queue/queue/g' $PWD/densify # Create the symlink to /opt sudo ln -s $PWD /opt/Densify # Perform the install cd /opt/Densify sudo chmod 755 install.sh sudo ./install.sh # Export to PATH if [ $SHELL == "/bin/zsh" ]; then if test -f $HOME/.zshrc; then echo 'export PATH=/opt/Densify:$PATH' >> $HOME/.zshrc source $HOME/.zshrc else echo "No zshrc Found! Please create a zsh config file and try again" fi else if [ $SHELL == "/bin/bash" ]; then if test -f $HOME/.bashrc; then echo 'export PATH=/opt/Densify:$PATH' >> $HOME/.bashrc source $HOME/.bashrc else if test -f $HOME/.bash_profile; then echo 'export PATH=/opt/Densify:$PATH' >> $HOME/.bash_profile source $HOME/.bash_profile else echo "No bashrc Found! Please create a bash config file and try again" fi fi else echo "Default Shell is not zsh or bash. Please add /opt/Densify to your PATH" fi fi
If there are no errors, you are good to go! Simply type the below command from opt/densify
to invoke the GUI, or open it from your dashboard.
densify

You can now compress as many PDF files as you need, using a GUI!
References
- StackOverflow question on reducing PDF size