CSS Formatter Online

What formatting does to a stylesheet

Formatting parses your CSS into rules and declarations, then re-prints it with consistent structure. Every selector block opens with the selector on its own line and a brace, each property–value pair sits on a separate indented line ending in a semicolon, and nested at-rules like @media indent their inner rules one level deeper. When a rule targets several selectors separated by commas, each selector is placed on its own line so a long group becomes a readable column.

The values and meaning of your CSS are untouched. Selectors, properties and values come out byte-identical — only the whitespace and line breaks change. The stylesheet applies exactly the same styles afterwards; it is just legible now.

How to format CSS

• Copy the CSS from a .css file, a build output, a browser DevTools panel or a <style> block.
• Paste it into the input panel.
• Choose an indent width — 2 spaces is the most common in CSS, 4 spaces gives wider steps, tabs let each editor decide.
• Read the formatted sheet on the right and copy or download it as a .css file.

The language detector recognises stylesheets automatically. If you are formatting a single declaration block with no surrounding context, switch the language selector to CSS to be sure.

Comments and at-rules survive

A careful CSS formatter has to respect more than just braces. Block comments written as /* … */ are preserved on their own lines instead of being collapsed away, so the notes you left for teammates stay intact. At-rules such as @media, @supports, @keyframes and @font-face are nested correctly, with their contained rules indented beneath them, which makes responsive breakpoints and animation keyframes easy to trace.

Strings inside values — a quoted font name or a url() path — are also handled safely, so a semicolon or brace that happens to appear inside quotes is never mistaken for a structural character.

Why a clean stylesheet matters

CSS rots faster than almost any other part of a codebase. Rules pile up, specificity wars break out, and a minified or badly indented sheet hides the duplication that causes them. Formatting is the first step to understanding what a stylesheet actually does: once every declaration is on its own line you can diff two versions cleanly, spot a property that is set three times, and see at a glance which media query a rule belongs to.

It also makes code review humane. A reviewer can comment on a single declaration line instead of squinting at a 4,000-character blob, and version control produces a small, meaningful diff when you change one value.

Everything runs locally

This formatter processes your CSS entirely in the browser with JavaScript. Nothing is uploaded, so proprietary design systems, unreleased themes and internal class names never travel across the network. You can verify it by watching the network tab while you format — there is no request — or by going offline and confirming the tool keeps working. Local processing is also instant: there is no upload round-trip, so even a large compiled stylesheet reflows the moment you paste it.