If you want your page to load fast and you want to get some nice score on pagespeed or lighthouse or in general.. you must optimize the size of your images.

I found simple script that I actually optimized even more in order to automate this tedious task for me, might as well share it here, if anybody is interested :)

However, in order to use it, first install following packages

sudo apt-get install optipng advancecomp pngcrush jpegoptim

Then simply use this script in your web source directory, you might configure multiple directories as an exception, in my case since I use Hugo, it’s like themes and _resources directories where I do not want to optimize images.

# Script adapted by pduchnovsky
# https://duchnovsky.com/2020/11/images-optimization-for-web/

# Add list of folder names to ignore array here, separated by space
ignore=("./themes/*" "./resources/*" "./assets/*")

# Array of png optimizers with their arguments
    "optipng -nb -nc"
    "advpng -z4"
    "pngcrush -rem gAMA -rem alla -rem cHRM -rem iCCP -rem sRGB -rem time -ow"

# File to check/create in order to stop processing already processed files since last run.

# Only use -newer option if file already exists
if [ -f "$file" ]; then
    option="-newer $file"

# Prepare arguments from ignore list
for ignored in "${ignore[@]}"; do
  ignorearg+="-not -path "*${ignored}" "

# Optimize png images with optimizers and their settings
for optimizer in "${optimizers[@]}"
    find . -type f $option -iname "*.png" $ignorearg -exec $optimizer  {} \;

# Optimize using jpegoptim
find . -type f $option -iregex .*\.jpe?g$ $ignorearg\
-exec jpegoptim -m85 --all-progressive -f --strip-all {} \;

# touch file so it updates last run-time
touch $file