diff --git a/README.md b/README.md
index 126fcaa..8ded270 100644
--- a/README.md
+++ b/README.md
@@ -1,19 +1,54 @@
-# WP-optimize
+## Bash script to optimize your images and convert them in WebP 
 
-### What does the script do ?
+### Prerequisite
 
-- install jpegoptim and optipng 
-- optimize all your images in /var/www
+* jpegoptim
+* optipng
+* WebP
 
-To run the script :
+Debian/Ubuntu :
 
+```bash
+sudo apt install jpegoptim optipng webp -y
 ```
-#For debian/Ubuntu
-bash <(wget --no-check-certificate -O - https://raw.githubusercontent.com/VirtuBox/wp-optimize/master/deb-optimize.sh)
-wget -qO optimize.sh 
 
-#For Centos/RedHat
-cd /var/www
-bash <(wget --no-check-certificate -O - https://raw.githubusercontent.com/VirtuBox/wp-optimize/master/centos-optimize.sh)
+Centos 7  :
 
+```bash
+sudo yum install optipng jpegoptim libwebp-tools -y
 ```
+
+### What does the script do
+
+1) optimize jpg images with jpegoptim
+2) optimize png images with optipng
+3) convert jpg & png images in WebP (without deleting them)
+
+WebP image name example for mybackground.png : mybackground.png.webp
+
+---
+
+### Usage
+
+1) Download the script and make it executable
+
+```bash
+wget https://raw.githubusercontent.com/VirtuBox/wp-optimize/master/optimize.sh
+chmod +x optimize.sh
+```
+
+2) Launch the script and set the path of your images as first argument
+
+```bash
+./optimize.sh /path/to/your/images
+```
+
+To avoid permissions issues, you can run the script with another user with sudo
+
+```bash
+sudo -u www-data ./optimize.sh /path/to/your/images
+```
+
+### Warning
+
+Conversion process can take a while, you can use `tmux` to launch the script and be able to close your ssh connection without interrupting conversion. Then just use `tmux attach` to login back in your tmux session.
\ No newline at end of file
diff --git a/centos-optimize.sh b/centos-optimize.sh
deleted file mode 100644
index 2944e2a..0000000
--- a/centos-optimize.sh
+++ /dev/null
@@ -1,11 +0,0 @@
-#!/bin/bash
-echo ""
-echo "Welcome to wp-optimize script"
-echo ""
-yum update &>/dev/null
-yum install optipng jpegoptim -y &>/dev/null
-find . -name *.jp* | xargs jpegoptim --strip-all -m76
-find . -iname '*.png' -print0 | xargs -0 optipng -o7 -preserve
-echo ""
-echo "Optimization Process done :)"
-echo ""
diff --git a/deb-optimize.sh b/deb-optimize.sh
deleted file mode 100644
index cdbbab3..0000000
--- a/deb-optimize.sh
+++ /dev/null
@@ -1,12 +0,0 @@
-#!/bin/bash
-echo ""
-echo "Welcome to wp-optimize script"
-echo ""
-apt-get update &>/dev/null
-apt-get install optipng jpegoptim -y &>/dev/null
-cd /var/www
-find . -name *.jp* | xargs jpegoptim --strip-all -m76
-find . -iname '*.png' -print0 | xargs -0 optipng -o7 -preserve
-echo ""
-echo "Optimization Process done :)"
-echo ""
diff --git a/optimize.sh b/optimize.sh
new file mode 100644
index 0000000..ddffa47
--- /dev/null
+++ b/optimize.sh
@@ -0,0 +1,24 @@
+#!/bin/bash
+
+
+# optimize jpg
+find "$1" -iname "*.jp*" -print0 | xargs -0 jpegoptim --strip-all -m76
+
+# optimize png
+find "$1" -iname '*.png' -print0 | xargs -0 optipng -o7 -preserve
+
+# convert png to webp
+find "$1" -iname "*.png" -print0 | xargs -0 -I {}  \
+bash -c '
+webp_version="$0".webp
+if [ ! -f "$webp_version" ]; then
+{ cwebp -lossless {} -o {}.webp; }
+fi'
+
+# convert jpg to webp
+find "$1" -iname "*.jp*" -print0 | xargs -0 -I {} \
+bash -c '
+webp_version="$0".webp
+if [ ! -f "$webp_version" ]; then
+{ cwebp -lossless {} -o {}.webp; }
+fi'