Free Code Formatter Online — Beautify JS, CSS, HTML, JSON Instantly

Inconsistent formatting is the single biggest source of noise in code reviews. Tabs versus spaces, trailing commas, semicolons, quote styles -- these arguments burn hours and generate zero value. A code formatter ends the debate by applying consistent rules automatically.

Our free code formatter beautifies JavaScript, TypeScript, CSS, HTML, JSON, and more -- directly in your browser. Paste your messy code, choose your preferences, and get perfectly formatted output in one click. No account, no install, no data uploaded.

Why Code Formatting Matters More Than You Think

Code is read far more often than it is written. Studies estimate developers spend 10x more time reading code than writing it. Consistent formatting reduces the cognitive load of reading, which directly impacts how fast your team can understand, debug, and modify a codebase.

Inconsistent formatting also pollutes version control history. When one developer uses tabs and another uses spaces, every commit contains dozens of whitespace-only changes mixed in with actual logic changes. This makes git blame useless and code reviews painful. A shared formatting standard -- enforced automatically -- eliminates this entirely.

Beyond readability, formatting catches structural issues. A formatter that rearranges your deeply nested ternary into multiple lines makes it obvious when the logic has become too complex. The formatted output is a mirror: if it looks ugly after formatting, the code itself may need restructuring.

Supported Languages and File Types

The formatter handles the languages most web developers work with daily:

• JavaScript / JSX -- ES6+, arrow functions, template literals, destructuring, async/await
• TypeScript / TSX -- type annotations, interfaces, generics, enums, decorators
• CSS / SCSS / Less -- selectors, media queries, custom properties, nesting
• HTML -- tag indentation, attribute formatting, embedded scripts and styles
• JSON -- object/array indentation, trailing comma removal (invalid in JSON)
• GraphQL -- queries, mutations, fragments, schema definitions
• Markdown -- heading spacing, list alignment, code block formatting
• YAML -- indentation normalization, multiline strings

The tool auto-detects the language from your code in most cases. If detection is wrong, use the manual dropdown to select the correct language. This is especially useful for ambiguous snippets like a few lines of CSS that could also parse as SCSS.

Customization Options Explained

Tab width (2 vs. 4 spaces). Two spaces is the standard for JavaScript/TypeScript ecosystems (Airbnb style guide, Google style guide, most open-source projects). Four spaces is more common in Python, Java, and C#. Our default is 2, but switch to 4 if that matches your project.

Single vs. double quotes. Single quotes dominate in JavaScript. Double quotes are standard in JSON (and required by the JSON spec). The formatter respects this automatically when you select JSON as the language. For JS/TS, pick whichever your team uses and stay consistent.

Semicolons. This is the most contentious JavaScript style choice. Both are valid -- JavaScript's automatic semicolon insertion (ASI) means code runs fine without explicit semicolons in most cases. The formatter lets you toggle them on or off globally.

Print width. This controls where the formatter wraps long lines. The default (80 characters) is a widely accepted standard dating back to terminal widths. Some teams prefer 100 or 120 for modern widescreen monitors. Shorter print widths produce more vertical code; longer widths keep complex expressions on a single line.

Code Formatting Best Practices

Pick a standard and enforce it project-wide. It doesn't matter whether you choose tabs or spaces, single or double quotes. What matters is that every file in your project follows the same rules. Inconsistency is the enemy, not any particular style choice.

Format on save, not on commit. If you only format at commit time, you spend your entire coding session looking at unformatted code. Configure your editor to format every time you save. This way, formatted code is the only thing you ever see.

Don't format generated code. Build artifacts, compiled output, vendor libraries, and auto-generated files should be excluded from formatting. Add them to your ignore configuration. Formatting minified vendor code will produce a massive, unreadable mess.

Use our online formatter for quick fixes. When you're working in a terminal, editing a config file on a remote server, or reviewing code in a GitHub PR, you don't always have your editor available. Paste the code into the tool, format it, and paste it back. It takes three seconds.

Combine formatting with linting. Formatters handle style. Linters handle correctness. Use both. Format first (fix whitespace and structure), then lint (fix unused variables, missing error handling, and anti-patterns). They complement each other -- they don't overlap.

When to Format (and When Not To)

Always format: any code you're about to commit, any code you paste into documentation, any code you share in a pull request description, and any config files (JSON, YAML) you edit by hand.

Skip formatting: minified production bundles (they're meant to be small, not readable), code you're quoting from another project exactly as-is (preserve their style), and legacy files where a formatting change would generate hundreds of diff lines with zero logic changes.

For legacy codebases, the best approach is incremental adoption. Format files as you touch them. Over time, the entire codebase converges on the standard without a single massive "format everything" commit that breaks git blame.

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Frequently Asked Questions

What languages does the code formatter support?

The formatter supports JavaScript, TypeScript, JSX, TSX, CSS, SCSS, Less, HTML, JSON, GraphQL, Markdown, and YAML. It auto-detects the language from your code, or you can select it manually from the dropdown.

Does the formatter change my code logic?

No. The formatter only changes whitespace, indentation, line breaks, and stylistic elements like quote type and trailing commas. It never modifies variable names, function logic, or program behavior. The output is functionally identical to the input.

Can I customize tab width and quote style?

Yes. You can set tab width (2 or 4 spaces), choose between single and double quotes, toggle semicolons on or off, and set a print width for line wrapping. These match the most common options teams configure in their formatting rules.

Is this the same as a linter?

No. A formatter fixes code style -- indentation, spacing, line breaks. A linter finds potential bugs and enforces coding patterns like unused variables or missing error handling. Use both: format first, then lint.