Minify CSS files using the cssnano minification library via PostCSS. Minify files with a command or automatically on save, with optional source map generation.
Installation
Launch VS Code Quick Open (Ctrl+P), paste the following command, and press enter.
Minify CSS files in VS Code using cssnano (via PostCSS) — the same minifier used under the hood by webpack, Vite, and Parcel.
Minify the active file with a command, or enable automatic minification on save. Output is written to a .min.css file alongside the source, with optional source map generation.
Features
One-command minification of the active CSS file.
Minify on save — automatically, for all files or only those that already have a .min.css.
Selectable cssnano preset — default, advanced, or lite.
Source maps — optionally emit a .min.css.map and a sourceMappingURL comment.
Built on actively maintained, modern tooling (cssnano + PostCSS).
Usage
Command palette → Minify Current CSS File — minifies the currently open CSS file immediately.
On save — set minifycss.minifyOnSave to minify automatically whenever a CSS file is saved.
Output is written to <filename>.min.css in the same directory. .min.css files are never re-processed.
Settings
Setting
Default
Description
minifycss.minifyOnSave
"No"
"No" — disabled; "Existing" — only if a .min.css already exists; "All" — always
minifycss.preset
"default"
cssnano preset: "default", "advanced", or "lite" (see below)
minifycss.generateSourceMap
false
Write a .min.css.map file and append a sourceMappingURL comment
minifycss.successNotificationStatusBar
false
Show a status bar message on success
minifycss.successNotificationInformationMessage
false
Show an info popup on success
cssnano presets
default — safe optimisations suitable for most projects.
advanced — more aggressive optimisations; may alter some CSS behaviour (e.g. colour conversion, selector merging).
lite — minimal optimisations. Note: cssnano-preset-lite v5 is not officially compatible with cssnano v8 — use with caution.
Source & issues
Source code, contributing guidelines, and issue tracker are on GitHub.
