✨ JavaScript Beautifier

JavaScript Beautifier reformats JavaScript source so minified, generated, or inconsistently spaced code is easier to read. It adjusts indentation, brace placement, spacing, and line breaks without intentionally changing what the script does.

Use it when you need to inspect a bundled snippet, clean up copied browser-console code, prepare a readable sample for a bug report, normalize indentation before review, or compare two versions of the same script without whitespace noise.

JavaScript syntax is defined by the ECMAScript lexical grammar. Whitespace and comments are usually ignored by the interpreter, but line terminators can still matter for automatic semicolon insertion. MDN's JavaScript lexical grammar reference is a practical companion for comments, strings, template literals, whitespace, and line terminator behavior.

• Indentation: switch between spaces and tabs, with 2, 4, or 8 character indentation.
• Brace style: keep opening braces on the same line, move them to a new line, or use the hybrid option.
• Line handling: preserve existing blank lines where useful and set a target maximum line width for readable output.
• Whitespace cleanup: collapse repeated spaces, add readable breaks after braces and semicolons, and preserve string/comment text.
• Checks: flag common issues such as unmatched quotes, unmatched braces, and likely missing semicolons.

Example input:

function total(cart){let sum=0;cart.forEach(item=>{sum+=item.price*item.qty;});return sum;}

Example output:

function total(cart){
    let sum=0;
    cart.forEach(item=>{
        sum+=item.price*item.qty;
    });
    return sum;
}

This is a beautifier, not a full parser, transpiler, or security scanner. It does not execute code, repair every syntax error, understand every framework convention, or guarantee that generated bundles become maintainable source. Review the result before committing it, especially when formatting code that relies on unusual automatic semicolon insertion, regular expressions, template literals, or build-tool output.

The interactive page formats code in your browser as you type. The optional API endpoint performs the same task server-side, so avoid sending private keys, credentials, proprietary source, or production secrets through the API request body.