CSSフォーマッター
無料のCSSフォーマッターとミニファイアです。乱雑なCSSをPrettierのデフォルト設定できれいに整形したり、コメントや空白を削除して最小のスタイルシートを作成したりできます。Sass風のセレクターを含むあらゆるCSSでブラウザ内で動作します。
Runs in your browserUpdated Apr 26, 2026
CSS Input
Output
よくある質問
›Can it format Sass or nested CSS?
Yes — Prettier's PostCSS parser handles modern CSS features including nesting, custom properties, container queries, @supports, and more.
›Is the minifier production-grade?
It's good for shipping small-to-medium stylesheets: strips comments, collapses whitespace, tightens syntax. For maximum compression (colour rewrites, shorthand collapsing) you want a dedicated tool like csso or Lightning CSS in your build pipeline.
›Will it break my @media or @supports queries?
No — those are preserved and pretty-printed the same way Prettier does in an IDE.
›Is my CSS sent to a server?
No — everything runs in your browser.