JavaScript Beautifier & Formatter

Make Your Code Readable Again

Reading unformatted code is frustrating. Whether you have inherited a messy legacy project, copied a snippet from a forum that lost its indentation, or are trying to debug a minified script from a production server, unstructured JavaScript is a headache. The JavaScript Beautifier solves this by instantly reformatting raw code into a clean, standardized structure.

This tool acts as a "pretty printer" for your scripts. It takes dense, hard-to-read blocks of text and reorganizes them using proper indentation, line breaks, and spacing rules. It turns a single line of compressed gibberish into a logical, readable program. This is essential for developers who need to understand the logic flow of a script without straining their eyes on a wall of text.

Customizing Your Style Guide

Every developer has a preferred coding style. Some strictly use two spaces for indentation; others swear by four. Some put opening braces on the same line, while others prefer new lines. This tool respects those preferences.

Before you process your code, look at the "Formatting Options" panel.

• Indent Size: Choose between "2 spaces", "4 spaces", or "Tab". This ensures the output matches your project's existing style guide (e.g., Airbnb, Google, or StandardJS).

• Brace Style: Control where the { character appears. "Collapse" puts it on the same line (common in JS), while "Expand" puts it on a new line (common in C#).

• Preserve Empty Lines: Keep this checked if you want to retain the vertical spacing you added to separate logical blocks of code.

• Break Chained Methods: Useful for long sequences like .map().filter().reduce(). Checking this forces each method call onto a new line for better readability.

From Minified to Maintainable

A primary use case for this tool is to unminify JavaScript. Minification is the process of removing all unnecessary characters (spaces, newlines, comments) to reduce file size for faster web loading. While great for browsers, it makes the code impossible for humans to edit.

By pasting minified code into the input area and clicking "Beautify JavaScript," you reverse this process visually. The tool reconstructs the structure. It adds line breaks after semicolons, indents nested functions, and separates blocks. Note that while it restores the structure, it cannot restore original variable names if they were shortened (obfuscated) during minification. Variable a will remain a, but now you can clearly see the loop it belongs to.

Validating and Cleaning Code

Beyond just "pretty printing," this tool helps spot errors. A missing closing bracket } in a large file can be hard to find. When you format the code, the indentation will often reveal the mistake visually—if a block of code is indented too far or not enough, it usually points to a structural error in the lines above it.

You can also use the tool to "Minify JavaScript." If you have written clean, spacious code and want to compress it for production, the "Minify" button does the opposite operation. It strips out whitespace and comments to create a compact version ready for deployment.

Client-Side Processing

Security is a major concern when working with proprietary code. You do not want your internal business logic or API keys sent to a public server.

This JS formatter operates entirely within your browser. It uses JavaScript libraries running on your local device to process the text. Your code is never uploaded to an external database or cloud server. Once you close the tab, the data is wiped. This allows you to format sensitive scripts safely without risking a data leak.

Limitations of Formatting

This tool focuses on syntax presentation, not logic correction. It will make your code look good, but it will not fix bugs or syntax errors. If your input code is invalid (e.g., missing a parenthesis), the formatter might produce unexpected results or fail to process certain sections.

It also supports modern JavaScript (ES6+), but extremely new or experimental syntax features might occasionally cause formatting quirks. It is always good practice to test the formatted code to ensure it runs as expected.

Usage Tips

Use the "Paste from Clipboard" button for speed. If you are copying a huge library like jQuery or React to inspect it, pasting manually can sometimes lag the browser. The button handles large data insertion more efficiently.

Check the "Output Stats" bar after formatting. It shows you the change in line count and file size. This is a quick way to verify that the unminification worked (line count should increase drastically) or that minification was effective (file size should drop).