**Debian Jessie**

To enable the touchpad tapping permanently , copy the `50-synaptics.conf` file to `/etc/X11/xorg.conf.d` then edit it by adding `Option "TapButton1" "1"` 

 cp /usr/share/X11/xorg.conf.d/50-synaptics.conf /etc/X11/xorg.conf.d/50-synaptics.conf

The `/etc/X11/xorg.conf.d/50-synaptics.conf` should be:



 Section "InputClass"
 Identifier "touchpad catchall"
 Driver "synaptics"
 MatchIsTouchpad "on"
 Option "TapButton1" "1"
 Option "TapButton2" "3"

Reboot your system

**Debian Stretch** (updated)

Remove the `xserver-xorg-input-synaptics` package. **(important)**

 # apt remove xserver-xorg-input-synaptics
Install `xserver-xorg-input-libinput`:

 # apt install xserver-xorg-input-libinput

>In most cases, make sure you have the `xserver-xorg-input-libinput` package installed, and not the `xserver-xorg-input-synaptics` package. 

Create the `40-libinput.conf` file:

 # echo 'Section "InputClass"
 Identifier "libinput touchpad catchall"
 MatchIsTouchpad "on"
 MatchDevicePath "/dev/input/event*"
 Driver "libinput"
 Option "Tapping" "on"
 EndSection' > /etc/X11/xorg.conf.d/40-libinput.conf
restart your DM; e,g:

 # systemctl restart lightdm
or

 # systemctl restart gdm3
Debian wiki : [Enable tapping on touchpad][1]


 [1]: https://wiki.debian.org/SynapticsTouchpad#Debian_9_.22Stretch.22