LESS - Overview


LESS is a CSS pre-processor that enables customizable, manageable and reusable style sheet for website. LESS is a dynamic style sheet language that extends the capability of CSS. LESS is also cross browser friendly.

CSS Preprocessor is a scripting language that extends CSS and gets compiled into regular CSS syntax, so that it can be read by your web browser. It provides functionalities like variables, functions, mixins and operations that allow you to build dynamic CSS.


Let us now understand why do we use LESS.

  • LESS supports creating cleaner, cross-browser friendly CSS faster and easier.

  • LESS is designed in JavaScript and also created to be used in live, which compiles faster than other CSS pre-processors.

  • LESS keeps your code in modular way which is really important by making it readable and easily changeable.

  • Faster maintenance can be achieved by the use of LESS variables.


LESS was designed by Alexis Sellier in 2009. LESS is an open-source. The first version of LESS was written in Ruby; in the later versions, the use of Ruby was replaced by JavaScript.


  • Cleaner and more readable code can be written in an organized way.

  • We can define styles and it can be reused throughout the code.

  • LESS is based on JavaScript and is a super set of CSS.

  • LESS is an agile tool that sorts out the problem of code redundancy.


  • LESS easily generates CSS that works across the browsers.

  • LESS enables you to write better and well organized code by using nesting.

  • Maintenance can be achieved faster by the use of variables.

  • LESS enables you to reuse the whole classes easily by referencing them in your rule sets.

  • LESS provides the use of operations that makes coding faster and saves time.


  • It takes time to learn if you are new to CSS preprocessing.

  • Due to the tight coupling between the modules, more efforts should be taken to reuse and/or test dependent modules.

  • LESS has less framework compared to older preprocessor like SASS, which consists of frameworks Compass, Gravity and Susy.