Both Sass and Less are CSS preprocessors.
From keycdn.com
A CSS preprocessor is basically a scripting language that extends CSS and then compiles it into regular CSS.
So Sass and Less don't change the functionality of CSS, as they are compiled into plain old CSS. What they do is make it easier to write and maintain CSS with tools such as mixins, nesting, variables, and more.
SCSS, which stands for 'Sassy CSS' is one of two syntaxes for Sass.
From the sass reference:
The second and older syntax, known as the indented syntax (or sometimes just "Sass"), provides a more concise way of writing CSS.
The difference
Both Sass and Less have very similar features. There are syntactical differences, for example, Sass uses $ for variables whereas less uses @ .
There are some slightly more subjective differences, this website claims that "LESS Has More User-Friendly Documentation Than SCSS", however personally I have found the SCSS documentation and examples very easy to use.
MarkSheet
marksheet.io › sass-scss-less.html
Sass vs SCSS vs Less - Free tutorial to learn HTML and CSS
Less https://lesscss.org/ Sass https://sass-lang.com/ They both have been around for several years. We’re going to use Sass. Sass has 2 syntaxes available: Sass itself (Syntactically Awesome StyleSheets) in .sass files · SCSS (Sassy CSS) in .scss files, which is something halfway between regular CSS and Sass ·
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Both Sass and Less are CSS preprocessors.
From keycdn.com
A CSS preprocessor is basically a scripting language that extends CSS and then compiles it into regular CSS.
So Sass and Less don't change the functionality of CSS, as they are compiled into plain old CSS. What they do is make it easier to write and maintain CSS with tools such as mixins, nesting, variables, and more.
SCSS, which stands for 'Sassy CSS' is one of two syntaxes for Sass.
From the sass reference:
The second and older syntax, known as the indented syntax (or sometimes just "Sass"), provides a more concise way of writing CSS.
The difference
Both Sass and Less have very similar features. There are syntactical differences, for example, Sass uses $ for variables whereas less uses @ .
There are some slightly more subjective differences, this website claims that "LESS Has More User-Friendly Documentation Than SCSS", however personally I have found the SCSS documentation and examples very easy to use.
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SCSS and LESS are both "supersets" of vanilla CSS. That means valid CSS is automatically also valid SCSS and LESS, but not necessarily the other way around.
The difference between SCSS and LESS is that they have a different syntax. They mostly have the same functionalities.
ELI5: SASS vs. LESS
I would suggest that you stick with CSS for some time and not bother with fancy stuff like LESS, SASS, CoffeScript, HAML and lots of other cool sounding names. These are helpful but an overkill for beginners like you. Start with the basics, create vanilla HTML + CSS websites, maybe sprinkle them with some JavaScript. Learn to create semantic html, modular css, adopt consistent naming conventions, learn about cross-browser issues. After you've done a couple of static websites, start experimenting :) Include some css preprocessors, html preprocessors, css frameworks or js frameworks in you workflow. Also, not Java but JavaScript. These are different languages. DO invest time in learning JavaScript (not jQuery!!!), all its quirks, strengths and weaknesses. P.S. I prefer SASS. A small clarification: i did not suggest to not learn jQuery, it's a great tool that saved my sanity many times. I suggested that the beginner should learn JavaScript first and only then - jQuery. Why? the abundance of jQuery plugins that duplicate native JavaScript functions, clearly people are not aware of js standart library i've interviewed lots of people who claim that they know jQuery language (wait what?), but when you bring up JavaScript in conversation you get a blank stare in response http://www.doxdesk.com/img/updates/20091116-so-large.gif (i know it's fake) People are lazy. Many of those who go straight for jQuery, never care to look back - see what's under the hood and learn JavaScript properly. More on reddit.com
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March 2, 2014Ask HN: SCSS/Sass vs. LESS
There are large projects that use both technologies, such as Bootstrap (LESS) and Jekyll (SCSS/Sass) just to name a couple · However, it seems like on a project-to-project basis, people tend to prefer to use Sass over LESS. I've heard some vague reasons why (such as looping and proper ... More on news.ycombinator.com
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August 14, 2014LESS vs SASS/SCSS
Jacob Miranda is having issues with: Are there any differences between the two and is there one you guys prefer to choose? And how should I go about using one or the other? ... More on teamtreehouse.com
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Why I don’t deeply nest SASS and LESS rules and neither should you
Targeting generic tag names like header, nav, and footer is almost never a good idea since they could be used in contexts you haven’t anticipated. For instance, a blog page could have an overall header and footer, and then a header and footer for each post. I really don't like this argument. In the case of container tags such as header and nav, you should have a default base style, and any edge cases should override that with a more specific selector. This also frees up a useless class name on your main header and nav tags. In the case of things like headings (h1-6), they should always be targeted by their tag name, because headings should have a consistent style across the site. While I agree that decoupling CSS from HTML is good practice, it seems silly to assume you're going to have unanticipated edge cases in something like this and work around them from the start. Sure you could have a header and a footer for each post in addition to an overall header and footer, but then you can just target those elements more specifically. You're either doing yourself a disservice by removing the cascading effect of CSS by removing the common property between two header tags ( the tag name ), or you're going to be adding the .header class to all of your headers anyway, in which case why not just use the tag name and save yourself some bloat? More on reddit.com
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May 21, 2013Videos
07:40
LESS and SASS - YouTube
06:43
Why you should use a CSS Preprocessor! SASS, LESS are Better than ...
01:34
100. Why we're using SASS instead of LESS and Stylus - YouTube
06:34
How To Use Variables in CSS without SASS or LESS in 10 Minutes ...
05:07
#04 - Difference between SASS, SCSS, LESS & CSS - (தமிழி...
02:23
SASS VS. SCSS? | What's the difference and which should you use?
KeyCDN
keycdn.com › blog › sass-vs-less
CSS Preprocessors - Sass vs Less - KeyCDN
January 13, 2023 - You can think of them as more of a programming language designed to make CSS more maintainable, themeable, and extendable. Both Sass and Less are backward compatible so you can easily convert your existing CSS files just by renaming the .css file extension to .less or .scss, respectively.
CSS-Tricks
css-tricks.com › sass-vs-less
Sass vs. Less | CSS-Tricks
January 10, 2020 - You should really try out sass then – you would really see some great benefits it really improves the way you work and the syntax just makes “more sense” than less – less seems to have fallen behind on all the different parameters tough this comment is 2 years old i think its worth changing to sass! or i would pref. scss – cause sass gives a lot syntax errors if you’r not really strict when you write
IONOS
ionos.com › digital guide › websites › web development › sass
SASS vs LESS vs SCSS - That are the differences - IONOS
October 12, 2020 - Each developer can decide for themselves whether they would like to move away from the CSS rules or stay closer to the original. LESS doesn’t offer this choice. Here, users have to stick with the old rules. Code in LESS is automatically a superset of CSS: All source text formulated in CSS also functions in LESS – just like with SCSS.
Cynoteck
cynoteck.com › blog-post › sass-vs-less-what-to-choose
SASS vs LESS: What to Choose?
November 19, 2025 - Both these CSS Pre-processors – SASS vs LESS are unique template expansions that make planning and developing simpler and more effective.
Reddit
reddit.com › r/webdev › eli5: sass vs. less
r/webdev on Reddit: ELI5: SASS vs. LESS
March 2, 2014 -
hey guys,
i'm starting to get into web development on my own, just wanted a cool new hobby and I've always wanted to design my own website. I just finished the courses on html, CSS and Java from codeacademy. From browsing this forum and talking to people, I foudn out about SASS and LESS too, extremely interesting, i didn't even know about them when I first started! Just a question, I've been researching, but I still don't know the difference between SASS and LESS, can someone help? Which one is better to do? What do most professional use? and lastly, why are SASS and LESS better than CSS itself?
EDIT: changed "learning" to finishing courses on codeacademy, since I know there is a ton more to learn.
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I would suggest that you stick with CSS for some time and not bother with fancy stuff like LESS, SASS, CoffeScript, HAML and lots of other cool sounding names. These are helpful but an overkill for beginners like you. Start with the basics, create vanilla HTML + CSS websites, maybe sprinkle them with some JavaScript. Learn to create semantic html, modular css, adopt consistent naming conventions, learn about cross-browser issues. After you've done a couple of static websites, start experimenting :) Include some css preprocessors, html preprocessors, css frameworks or js frameworks in you workflow. Also, not Java but JavaScript. These are different languages. DO invest time in learning JavaScript (not jQuery!!!), all its quirks, strengths and weaknesses. P.S. I prefer SASS. A small clarification: i did not suggest to not learn jQuery, it's a great tool that saved my sanity many times. I suggested that the beginner should learn JavaScript first and only then - jQuery. Why? the abundance of jQuery plugins that duplicate native JavaScript functions, clearly people are not aware of js standart library i've interviewed lots of people who claim that they know jQuery language (wait what?), but when you bring up JavaScript in conversation you get a blank stare in response http://www.doxdesk.com/img/updates/20091116-so-large.gif (i know it's fake) People are lazy. Many of those who go straight for jQuery, never care to look back - see what's under the hood and learn JavaScript properly.
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They are essentially the same, preprocessors for css. Only real difference is SASS was written in Ruby and LESS in JS. You are able to write your own mixins (think of methods from Java), define variables, and separate out your css into partials (kinda like classes in Java). You can also nest selectors within one another, however rule of thumb is if you nest more than 4 times, you're doing it wrong. Both accomplish one major concept, DRY - don't repeat yourself. It boils down to preference. I prefer SASS, but I have nothing against Less.
Frontend Mentor
frontendmentor.io › articles › css-preprocessors-sass-or-less-which-to-choose-JOI20I1xNL
Sass vs Less | Which CSS Preprocessor to Choose
January 23, 2024 - Sass is essentially known for its slower compile speed compared to Less. This is due to its extensive feature set. It efficiently processes Sass or SCSS files into CSS, and the speed is often influenced by factors such as file size and complexity.
Achilles Interactive
achillesinteractive.com › blog › what-is-the-difference-between-sass-scss-and-less
What is the difference between Sass, SCSS, and Less? | Achilles Interactive
It uses a CSS-like syntax with the addition of variables, mixins, and nesting. Unlike Sass and SCSS, Less requires a JavaScript runtime to compile to CSS.
Syncfusion
syncfusion.com › blogs › angular › less versus css
LESS versus CSS | Syncfusion Blogs
April 11, 2025 - LESS, also known as Leaner Style Sheets, is a dynamic CSS preprocessor that compiles and generates CSS during runtime on the server or client side.
Quora
quora.com › What-is-the-difference-between-LESS-and-CSS-Which-is-a-better-one
What is the difference between LESS and CSS? Which is a better one? - Quora
CSS is static because you can not write any loops or other programming constructs like if-else, etc. On the other hand LESS or (SCSS) are CSS pre-processors. You can think of it as CSS on steroids.
GeeksforGeeks
geeksforgeeks.org › css › what-are-the-differences-between-less-and-sass
What are the differences between LESS and SASS? - GeeksforGeeks
January 13, 2025 - LESS: Simpler syntax, JavaScript-based, and integrated into projects quickly. SASS: Offers advanced features, is more robust, and supports two syntaxes (SCSS and indented).
Hacker News
news.ycombinator.com › item
Ask HN: SCSS/Sass vs. LESS | Hacker News
August 14, 2014 - There are large projects that use both technologies, such as Bootstrap (LESS) and Jekyll (SCSS/Sass) just to name a couple · However, it seems like on a project-to-project basis, people tend to prefer to use Sass over LESS. I've heard some vague reasons why (such as looping and proper ...
Laracasts
laracasts.com › discuss › channels › laravel › sass-vs-less
SASS vs. LESS
We cannot provide a description for this page right now
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I think Chris Coyier wrote a great and unbiased article on the two.
http://css-tricks.com/sass-vs-less/
It seems they accomplish the same thing, in slightly different ways.
Just two months ago I started using sass. (And I'm using the scss syntax as it's more comfortable, and more like traditional css with the brackets).
I just eventually dove into it, combed through the sass documents as I built, try to go back through and use variables, mixins, etc as much as possible. It will slow down your css development at first, but soon enough you'll be faster at writting css, plus some of the features it has is freaking cool.
Another reason I chose sass is because I wanted to try out the compass framework with it.
As far as a preproccessor, I use Scout (free) on my work PC, and right now Scout (free) on my mac, but am seriously contemplating using CodeKit ($20-$25) for my mac.
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Just like to write a quick reply:
SCSS / SASS!
Hashnode
sivalaxman8.hashnode.dev › styles-in-web-development-scss-vs-sass-vs-less-vs-css-vs-css-modules-vs-styled-components
SCSS vs. SASS vs. LESS vs. CSS vs. CSS Modules vs. Styled ...
September 7, 2023 - SCSS and SASS files need to be compiled into regular CSS before a browser can understand them. LESS is another CSS preprocessor that simplifies your stylesheets and streamlines your workflow.
Martyfriedel
martyfriedel.com › home › blog › moving from less to scss
Moving from LESS to SCSS | Marty Friedel
When looking at which preprocessor to use, it was between LESS and SASS. And LESS won hands down for its so-close-to-CSS syntax. Basically CSS with variables and helpers. But more and more was seeing modern frameworks use SCSS, especially when ...
ProcessWire
processwire.com › off topic › dev talk
Out of interest, who's using Less/Sass vs plain old CSS - Dev Talk - ProcessWire Support Forums
June 6, 2016 - One of the things I've put off learning has been LESS/SASS, seeing as I've always managed ok with CSS and there's never time enough to learn every new technology is there?! Was just interested to see who used it occasionally, the whole time, never at all, waste of time, lifesaver etc... I've cert...
Woutermuller
woutermuller.net › sass-vs-scss
Why I prefer the SASS indented syntax over the SCSS syntax
Also, cause you don’t have to use curly brackets and semi-colons (more on that later on), there is a lot less clutter, which makes it easier to focus on the parts that really matter.
Sass
sass-lang.com › guide
Sass: Sass Basics
Sass has two syntaxes! The SCSS syntax (.scss) is used most commonly. It’s a superset of CSS, which means all valid CSS is also valid SCSS. The indented syntax (.sass) is more unusual: it uses indentation rather than curly braces to nest statements, and newlines instead of semicolons to separate them.