Firefox tricks to take screenshot without any addon or tool

This tutorial will  helps you to take  screenshot right from Firefox without any
addon or third party tool

Step 1:
Open developer tool in Firefox(Ctr+shift+I)
Step 2:

Look for Responsive Design View in the menu

Step 3:

You can select which screen-size to take screenshot and just click on camera icon to take screenshot.

Here is few other shortcuts

Downloads Ctrl + Shift + Y
Add-ons Ctrl + Shift + A
Toggle Developer Tools F12
Ctrl + Shift + I
Web Console Ctrl + Shift + K
InspectorCtrl + Shift + C
DebuggerCtrl + Shift + S
Style EditorShift + F7
ProfilerShift + F5
NetworkCtrl + Shift + Q
Developer ToolbarShift + F2
Responsive Design ViewCtrl + Shift + M
Scratchpad Shift + F4  <----- Try this 
Page Source Ctrl + U
Browser ConsoleCtrl + Shift + J
Page InfoCtrl + I

Get Full list at