About

In the ecosystem of modern web development, code readability is not merely aesthetic - it is a functional necessity. This JavaScript Beautifier engine addresses the critical need to transform minified, obfuscated, or poorly formatted scripts into strict, standardized syntax trees. Minification (removing whitespace/comments) is essential for production payload optimization (reducing kiloBytes), but it renders code illegible for human debugging.

This tool utilizes a custom lexical tokenizer to parse the Abstract Syntax Tree (AST) structure of your code. Unlike simple regex replacers, it respects context - preserving strings, differentiating between division operators (/) and Regular Expressions, and maintaining valid logic flows. Whether you are auditing third-party libraries, debugging legacy systems, or enforcing team style guides (e.g., Airbnb, StandardJS), this engine provides granular control over indentation depth, brace placement, and operator spacing.

Formulas

The core logic follows a recursive descent strategy to calculate indentation depth D at any given line L based on the token stack:

{

D_n+1 = D_n + 1 if token ∈ { "{", "[", "(" }D_n+1 = D_n - 1 if token ∈ { "}", "]", ")" }

Operator spacing is applied via token type analysis, ensuring x=y becomes x = y while preserving unary operators like ++i.

Reference Data

Style Guide	Indentation	Semicolons	Quotes	Trailing Comma	Brace Style
Airbnb	2 Spaces	Required	Single	ES5 (Multi-line)	Collapse (One True Brace)
Google	2 Spaces	Required	Single	None	Collapse
StandardJS	2 Spaces	Forbidden	Single	None	Collapse
jQuery Core	Tabs	Required	Double	None	Collapse
Idiomatic.js	Tabs / 4 Spaces	Required	Single	None	Expand / Collapse
CommonJS	Tabs	Required	Single	None	Collapse
Crockford	4 Spaces	Required	Single	None	End of Line

Frequently Asked Questions

This is the "slash ambiguity" problem in JS parsing. Our engine checks the *preceding* non-whitespace token. If the previous token is a keyword (like "return", 'typeof'), operator ('=', '('), or punctuation, the slash is treated as the start of a Regular Expression. If the previous token is an identifier or number, it is treated as a division operator.

Yes. This tool runs 100% client-side in your browser's memory. No code is sent to any backend server. You can verify this by inspecting the Network tab in your browser developer tools or running the tool offline.

No. A beautifier changes *formatting* (whitespace, newlines), not *logic*. If your input code has invalid syntax (e.g., missing closing braces), the beautifier may produce unexpected results or fail to parse correctly. Always validate syntax before formatting.

No. Minification is a destructive process that replaces variable names (e.g., 'userAuthentication') with short identifiers (e.g., "a", 'b'). This mapping is lost permanently unless you have the original source maps. This tool restores structure, not semantics.