Less CSS - SPLessons

Chapter 2




Less was introduced in the year 2009 by Alexis Sellier. The first version was written in Ruby and later replaced with JavaScript.

Less is known as CSS pre-processor that allows customization, managing and reusing the style sheet for a website. It is a cross browser friendly and a dynamic style sheet language that extends the CSS capability.

Less is a scripting language that is compiled using CSS syntax and can be read by any web browser. It is an open source and dynamic CSS built using the functionalities. The following are some of the functions.


The following are a few advantages.


The following are a few disadvantages.

Either Node.js or a web browser is mandatory to run the files. In real time, a user can include less.js in their websites and compile the linked .less stylesheets, which is slow and not recommended. So, the less stylesheets are compiled and deployed in regular CSS file online.

There are a number of graphical tools used to compile the files similar to Node.js. Some of the GUI compilers are as follows.

Graphical tools Platform
SimpLESS Windows, Mac OS X, Linux
WinLess Windows
CodeKit Mac OS X
Crunch Windows, Mac OS X
less.js-Windows Windows
less.app Mac OS X
mod_less Linux
clessc Windows, Linux, Mac OS X
grunt-contrib-less Node.js


  • The functions like mixins, variables, etc. are used to achieve dynamic CSS.
  • Each platform has its own GUI compiler, which is used to compile .less to .css file.