Unminified CSS

Detects unminified CSS that could be optimized


Rule ID	`perf/unminified-css`
Category	Performance
Scope	Per-page
Severity	warning
Weight	4/10

Solution

Minify CSS to reduce file size and improve load times. Use build tools like cssnano, clean-css, or PostCSS with cssnano plugin. Most bundlers (Webpack, Vite, esbuild) can minify CSS automatically in production mode. Minification removes whitespace, comments, and optimizes syntax.

Options

This rule supports the following configuration options:

Option	Type	Default	Description
`min_size_bytes`	unknown	`undefined`	Minimum CSS size in bytes to check for minification
`newline_ratio_threshold`	unknown	`undefined`	Newlines per character ratio threshold for unminified detection

Configuration example

[rules."perf/unminified-css"]
min_size_bytes = undefined
newline_ratio_threshold = undefined

Enable / disable

Disable this rule

[rules]
disable = ["perf/unminified-css"]

Disable all Performance rules

[rules]
disable = ["perf/*"]

Enable only this rule

[rules]
enable = ["perf/unminified-css"]
disable = ["*"]

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