Code Beautifier Online: Format HTML, CSS, JS

A code beautifier turns cramped or minified HTML, CSS and JavaScript into readable, consistently indented code. Paste your code into this free code beautifier, choose 2 spaces, 4 spaces or tabs, press Beautify, and copy the cleaned result. A Minify button is there for when you need compact code again.

What Is a Code Beautifier?

A code beautifier is a formatter that rewrites the whitespace in source code (line breaks, spaces and indentation) so people can read it, without changing what the code means. Browsers ignore most of that whitespace, so a stylesheet written on one line behaves exactly like the same stylesheet spread over fifty lines.

Readable layout matters to humans, not machines. Indentation shows which rules belong inside which block, one declaration per line makes a diff easy to scan, and consistent spacing keeps a team from arguing about style. Beautifying is also called pretty-printing or formatting. The opposite operation is minifying, which removes whitespace to shrink file size.

Code usually ends up unreadable for one of three reasons: it was minified for production, it was copied out of a browser's developer tools or a view-source page, or several people edited it with different habits. A beautifier fixes all three in one click.

How to Use the Code Beautifier

You can format a snippet in under ten seconds. Follow these steps:

1. Paste your HTML, CSS or JavaScript into the Input box. The placeholder shows three samples to give you an idea of what works.
2. Leave Language on Auto-detect, or pick HTML, CSS or JavaScript yourself if the guess looks wrong. A small note next to the menus tells you what was detected.
3. Choose your Indent style: 2 Spaces (the default), 4 Spaces or Tab.
4. Press Beautify to format the code, or press Minify to compress it.
5. Read the result in the Output panel, then press Copy to put it on your clipboard.
6. Press Clear to empty the fields and start with new code.

If you press a button with an empty input, the tool asks you to paste some code first. If copying fails, select the text in the output panel and copy it by hand.

Worked Example: Beautifying a Minified CSS Rule

Here is a typical case. You open a production stylesheet and find this single line:

.btn{color:#fff;background:#06c}

With Auto-detect on and 2 Spaces selected, pressing Beautify returns four short lines:

• .btn{
• color:#fff;
• background:#06c
• }

The selector sits on its own line, each declaration is indented by two spaces, and the closing brace returns to the left margin. Your characters are kept as you typed them, so the tool does not add spaces after colons or rewrite your values. Only the whitespace changes. Choose Tab and the same declarations are indented with a tab character instead.

Now try HTML. A link such as <a href="/pricing" class="btn" id="cta">Pricing</a> comes back with each attribute on its own indented line, which makes long tags with many attributes far easier to scan and compare.

How Does Each Language Get Formatted?

The tool applies different rules to HTML, CSS and JavaScript, and it is deliberately careful in each. Knowing what to expect helps you decide whether the output is what you need.

HTML

In HTML mode, the beautifier works on the inside of tags. Attributes move onto separate indented lines, and quoted attribute values stay intact. Text between tags, comments, and the contents of script, style, pre and textarea elements are left exactly as written, because changing whitespace there could change what a page displays. The tool does not re-indent nested child elements, so you keep control of your own line breaks between tags.

CSS

In CSS mode, each opening brace starts an indented block, each semicolon ends a line, and each closing brace returns to the outer level. Strings, comments and escaped characters are copied untouched. Content inside parentheses, such as a url() or a calc() expression, stays on one line instead of being split.

JavaScript

JavaScript is the trickiest language to format, so this mode is cautious. It keeps your strings and line boundaries and adjusts indentation around blocks. When it reaches something it cannot read with certainty, such as a backtick template string or a slash-delimited pattern, it keeps the rest of your code as you pasted it instead of guessing. That protects your logic, and it also means a very unusual script may be only partly reformatted.

How to Read and Act on the Results

A good result is code you can scan quickly: one declaration or statement per line, indentation that rises and falls with the braces, and no change in behavior. Check these points after each run.

• Wrong language detected. If a CSS snippet gets HTML rules, set the Language menu manually and press Beautify again.
• Indentation looks off in your editor. Match the Indent option to your project. Many front-end teams use 2 spaces, while others standardize on 4 spaces or tabs.
• Output looks unchanged. Your code may already be formatted, or the tool may have left a section alone on purpose. Compare before and after with the code diff tool to see exactly which lines moved.
• Output is too large. Minify produces compact code for production, but keep the beautified copy as your editable source.

Who Uses a Code Beautifier, and When?

A code beautifier is useful whenever you must read code you did not write or cannot easily open in an editor. These are the most common situations.

• Debugging minified files. You copy a compressed stylesheet or script from a live site and need to find one rule or function.
• Cleaning generated code. Visual builders often output dense CSS. After you create a shadow with the CSS box shadow generator or keyframes with the CSS animation generator, formatting the result makes it easier to merge into your stylesheet.
• Code reviews and tutorials. Consistent indentation makes snippets readable in pull requests, documentation and Q&A posts.
• Quick edits away from your setup. Editors such as VS Code, IntelliJ and Notepad++ have their own format commands, but on a borrowed computer or a locked-down machine, pasting code here is faster than installing anything.
• Learning. Beginners see structure more clearly when blocks are indented properly.

Best Practices and Troubleshooting Tips

You will get the best results by preparing your input and checking the output before you ship it.

• Format one language at a time. A pasted page that mixes HTML with long inline scripts and styles is better split into separate pieces so each gets the right rules.
• Paste complete code. A half-copied rule with a missing brace can produce odd indentation, because indentation follows the braces it finds.
• Pick one indent style per project. Mixing tabs and spaces across files creates noisy diffs.
• Test after minifying. Always load the compressed file in a staging copy before you replace a live one.
• Keep within the size limit. The tool accepts up to 500,000 characters. Longer input is rejected, so split large files into sections.
• Seeing an unreadable markup message? That means the HTML could not be processed. Look for a stray opening angle bracket or an unclosed quotation mark in a tag, fix it and try again.

Limitations to Know About

This tool formats HTML, CSS and JavaScript only. Searches such as code beautifier for JSON, SQL, Python, Java, C++ or PHP point to other languages, and those are not supported here, so pasting them will not give you proper results.

The beautifier also changes layout only. It does not fix syntax errors, rename variables, sort CSS properties, add missing semicolons or check that your code runs. Because the formatting is conservative, you may still want to adjust a few lines by hand, especially in HTML where the tool leaves the structure between tags alone.

Ready to clean up your code? Paste it into the Input box above, choose your indent, and press Beautify. For more helpers like this one, browse the full web developer tools collection.