Difference between CSS Variables and Preprocessor (original) (raw)

Last Updated : 5 Aug, 2025

In this article, You will learn the differences between the CSS variables (cascading variables) and CSS preprocessors. They both implement the extra capabilities into CSS in their own different ways.

CSS variables and preprocessors are two different things. Both have advantages and disadvantages. The CSS preprocessor is a language that can be used to define your own CSS rules. It could be used for custom properties or just for creating variables. On the other hand, the CSS variables (also called custom properties) are dynamic values that can be reused across multiple elements and style rules in a web page. You can define values ​​once and reference them in multiple places, making it easier to update and maintain your styles.

CSS variables: Like basic variables in any other programming language, CSS variables are also simple variables. These variables have a range in which they can be used and are used to store values. The main advantage of variables is also that they make it possible to update/modify the defined values from a single location while reusing the same values elsewhere in the defined range.

Some key points to remember while defining CSS variables

• Variables' name always start with a double hyphen (--) and terminate with a semi-colon.
• The best practice is to specify the variable inside the root: pseudo-class.
• While using the variable use var() keyword first and then inside mention the variable name. For ex. var(--white-color)

Syntax:

:root { --variable-name: value; }

--variable-name: This is the title of the variable that the programmer specifies. It is recommended to provide a meaningful name. It's a necessary parameter.

value: It is an optional parameter that can leave it blank but while using it accepts a fallback value.

For example: var(--white-color,#ffff)

The above example says if --white-color is not defined use #ffff instead.

It is not required to always use root: also called pseudo-class that can specify the scope at your convenience. The normal practice is to use root which specifies the global scope to utilize the specified variables throughout the code. The variable name is case-sensitive. For example: "--white-color" and "--WHITE_COLOR" is different.

Implementation:

property : var(--variable-name);

The variable name is always used inside the var() method.

Example: In this example, we are using the above-explained method.

HTML `