b2KIT

JavaScript Formatter & Beautifier

Format and beautify JavaScript code with configurable indentation, semicolons, and bracket style options.

Tested tool guide Tested browser tools Checked August 16, 2026

What JavaScript Formatter & Beautifier does, with a checked example

Paste JavaScript into this formatter to replace cramped or inconsistent layout with a readable, repeatable style. It adjusts whitespace, indentation, line breaks, semicolon presentation, and bracket placement according to the selected controls while leaving identifiers and expressions recognizable. The main surprise is that cleaner output is not evidence that the program is correct. Formatting can expose structure, but it does not establish that the source is valid, free of logic errors, or compatible with a particular runtime.

Worked example

A concrete input and expected output from the current implementation.

Input

if(ready){start();}

Expected output

if (ready) {
  start();
}

With two-space indentation, semicolons retained, and the opening bracket kept on the statement line, the block becomes three lines. Spaces are added around the condition and before the opening bracket.

How the result is produced

1

Structural layout

The formatter treats the submitted text as JavaScript and rewrites its visible layout. Nested function bodies, conditional blocks, loops, object expressions, and similar structures receive consistent indentation and line breaks. Compact token sequences such as `if(ready)` are spaced into a conventional readable form. The indentation selection determines how far each nested level moves from its parent.

2

Style controls

Semicolon and bracket settings control two choices that indentation alone cannot express. The semicolon option determines whether statement endings are displayed with the selected convention. Bracket style determines where applicable opening and closing brackets appear relative to their surrounding statement or block. These settings affect the generated text, so choose values that agree with the destination project's existing conventions.

Good uses

  • Expand a minified or single-line JavaScript snippet before tracing its nested conditions, callbacks, or object literals.
  • Normalize indentation and bracket placement in code copied from documentation, an issue report, or a browser console.
  • Preview how a small JavaScript fragment looks under a different semicolon or block-layout convention before editing a project file.

Limits and checks

  • Readable output does not certify valid syntax or correct behavior. Run the result in the intended JavaScript environment and use appropriate tests.
  • Semicolon choices deserve review because JavaScript automatic semicolon insertion can make adjacent lines form an expression differently from what their visual separation suggests.
  • The available controls cover only part of a complete project style. Do not assume the result matches an ESLint, Prettier, or repository-specific configuration.

Common questions

Does formatting change what the JavaScript does?

The purpose is to change presentation, not program behavior, and ordinary whitespace or indentation changes do not alter most JavaScript expressions. The answer is not an unconditional no, however. Semicolon changes can interact with automatic semicolon insertion, and comments or unusual line-sensitive constructs merit inspection. Review and test the returned source before replacing working code.

Can this replace a linter or a project formatter?

No. It is useful for producing readable JavaScript with the indentation, semicolon, and bracket choices exposed by this page. A linter can report suspicious constructs and enforce additional rules, while a project formatter may follow a checked-in configuration covering many more decisions. Use this tool for the displayed transformation, not as proof of repository compliance.

References and verification

The example and behavioral notes were checked against the browser implementation. Standards and primary references below define the relevant format, formula, or platform behavior.

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