performance/minify-disabled · Minification disabled

A build.minify:false left in vite.config ships unminified JS/CSS to production.

Severity: warning · Category: performance

What it checks

Flags a Vite config whose production build disables minification with build.minify: false.

The CLI statically parses vite.config.* (the first file in Vite’s own resolution order) and detects the literal form, with satisfies/as unwrapped:

• export default { … }
• defineConfig({ … }), including a same-file identifier passed as its argument
• a same-file alias export
• the CommonJS module.exports = { … } form

The Vite plugin instead reads the resolved config during vite build, so it also catches function-form and conditional configs, and never flags an override that doesn’t apply to the actual build.

Not flagged: minify: 'oxc' | 'esbuild' | 'terser' | true, and minify keys outside the build object. A project with no Vite config is not flagged by the CLI, which has nothing to parse; the plugin still judges the resolved value, including for an inline programmatic config.

An object spread that could override minify after the literal ({ minify: false, ...prod }) makes the value unknowable to static reading, so the CLI skips the finding. The plugin channel still judges the resolved value.

Why it matters

Vite minifies by default (oxc since Vite 8); turning it off is almost always a leftover from debugging a production issue. Unminified bundles are several times larger, so every route pays for it in download and parse time. Nothing in the toolchain warns you either: the build succeeds and dev behaves identically.

How to fix

Remove the override (the default already minifies), or scope it so production keeps minification:

import { defineConfig } from 'vite';

export default defineConfig(({ mode }) => ({
  build: {
    minify: mode === 'production'
  }
}));

Note the CLI’s static pass deliberately skips this conditional form. Only the plugin channel, which sees the resolved value, verifies which branch your build actually takes.

Mode differences

The two channels differ in strength. The CLI flags only the literal build.minify: false; a dynamic expression evaluating to false is invisible to it.

The Vite plugin judges the resolved value, so its verdict is exact for the build it runs in. When the offending config is dynamic, or the override comes from another plugin, the finding carries no line number and says the value came from the actual build. For an inline programmatic config, with no config file at all, it carries no file either.

Disabling

If unminified production output is intentional, turn the rule off in your config:

export default {
  rules: {
    'performance/minify-disabled': 'off'
  }
};