# less/less.js

Less. The dynamic stylesheet language.

Repository: https://github.com/less/less.js
Canonical: https://ross.abutalabs.com/products/lessjs
Homepage: http://lesscss.org
Language: JavaScript
License: Apache-2.0
License Family: permissive
Topics: stylesheet-language, language, css
Last push: 2026-08-13T22:21:40+00:00

## Health v2 (maintenance only)
Score: 93/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 97, release rhythm 85, longevity 100
- inputs: {"age_days": 6038, "days_push": 20, "days_rel": 20, "gap_med": 40, "n_releases_24m": 16}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 17029, forks 3368 (observed 2026-08-28T04:11:17.605321+00:00)

## What it is
Less.js is the official JavaScript compiler for Less, a backwards-compatible dynamic stylesheet language that extends CSS with variables, mixins, nesting, and functions. It can compile .less files to CSS via Node.js CLI, in-browser, or as a build-tool dependency.

## Use cases
- compile less files to css
- use variables and mixins in stylesheets
- nest css selectors
- preprocess styles in a node build pipeline
- compile styles in the browser for prototyping

## When to choose
- you maintain an existing codebase already using .less files
- you want a CSS-like preprocessor with a minimal learning curve
- you need variables, mixins, and functions in plain-CSS-style syntax

## When to avoid
- you are starting a new project where modern CSS (custom properties, nesting) or Sass/PostCSS may be a better fit
- you need a full-featured preprocessor with extensive ecosystem like Sass

## Facets
- artifact type: library
- maturity: stable
- function: css-framework, compiler, build-tool, cli
- domain: web-development, frontend, programming-languages, web-design
- platform: browser, cli, cross-platform
- tags: css-preprocessor, stylesheet-language, less, variables, mixins, transpiler, nodejs

## Member repositories
- less/less.js (main) score 93

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:11:17.605321+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T17:03:40.015968+00:00, confidence not recorded.
  - readme: https://github.com/less/less.js (fetched 2026-08-28T04:11:17.605321+00:00, sha 0de1fd1b25df)
  - homepage: http://lesscss.org (fetched 2026-08-29T08:01:57.015921+00:00, sha 4bb42aa7a902)
  - site_page: https://lesscss.org/features (fetched 2026-08-29T08:01:57.025405+00:00, sha d457c7bfa8b2)
  - site_page: https://lesscss.org/about (fetched 2026-08-29T08:01:57.029183+00:00, sha 5b8702d59b33)
- Data as of 2026-08-30T08:39:29.467469+00:00.