Guetzli is a Google program to optimize JPEG images. Unfortunately, it only works one file at a time. With this script in Python you can do it recursively a whole folder.

UPDATE GUI for Mac OS

Install

Guetzli must be installed on your system. Follow the official instructions. Guetzli

and 2.7.10 or Python 3.

After

pip3 install guetzli-recursively

Use

guetzli_recursively [folder]

Example

guetzli_recursively img/

out

img/tasks.jpg
Save 6%
img/portfolio/idecrea/space.jpg
It is not necessary to optimize
img/portfolio/home.jpg
Save 3%