JavaScript Formatter

JavaScript Formatter

JavaScript Formatter transforms minified, bundled, or poorly formatted JavaScript into clean, consistently indented code that you can read, debug, and maintain. We built six JavaScript utilities into one workspace so you can format, minify, validate, unescape strings, deobfuscate scripts, and count lines without switching between different tools. Paste your JavaScript into the code editor on the left, upload a .js file from your computer, or drag and drop it onto the workspace. All processing happens locally in your browser, so your source code never leaves your device and no account is required.

Free JavaScript Formatter with Configurable Beautifier

Minified JavaScript is compact and fast to download, but nearly impossible to read. Variable names become single characters, function bodies collapse onto single lines, and nested callbacks merge into unnavigable walls of text. The free JavaScript Formatter on this page takes any JavaScript input and expands it into a clean, consistently indented structure. Each statement appears on its own line with your chosen indent width. Function bodies, object literals, and array expressions are properly nested so you can follow the control flow at a glance.

Formatting Options for Your Coding Style

The options bar above the editor gives you three configurable formatting controls. The indent size dropdown sets the whitespace used for each level of nesting: 2 spaces, 4 spaces, or a real tab character. Brace style controls where opening braces are placed: on the same line as the function or control statement (collapse style, the JavaScript community default), or on a new line (expand style, also called Allman style). The single quotes checkbox converts all double-quoted strings to single-quoted strings, which is the preferred style in many JavaScript projects and ESLint configurations.

Upload JavaScript Files Directly

You can load JavaScript into the workspace three ways: paste it into the code editor on the left, drag and drop a file anywhere onto the workspace, or click the Upload JS button. We accept .js, .mjs, .cjs, .jsx, .ts, and .tsx files. Because everything runs in your browser, there is no file size limit imposed by a server, and your files never leave your machine. This makes the formatter safe for production scripts containing API keys, internal logic, and proprietary algorithms.

Online JavaScript Formatter with Minify and Validate Tools

Beyond formatting, this page includes complementary JavaScript utilities for a complete development workflow. Start by formatting minified production code to make it readable. Edit, debug, and review. Then use JS Minify to strip it back to the smallest output for deployment. Run JS Validate to catch missing brackets, unclosed strings, and unexpected tokens before shipping. JS Unescape decodes escape sequences from JSON payloads, API responses, and log files so you can read the actual text content. JS Deobfuscate helps you analyze obfuscated scripts by decoding hex and Unicode sequences and resolving common string array patterns. JS Line Counter gives you a comprehensive report of code metrics including cyclomatic complexity.

JS Minify for Smaller Production Files

The minifier performs the inverse of formatting. It removes all single-line and block comments, strips excess whitespace, and joins lines so the output occupies the fewest possible bytes. JavaScript engines parse the minified output identically to the original. Use it when you do not have a build tool like webpack or esbuild available, or for quick one-off minification before pasting code into a script tag.

JS Validate to Catch Syntax Errors Early

The validator uses the browser built-in JavaScript engine to check your code. If parsing succeeds, you see a green confirmation with counts for total lines, code lines, characters, functions, arrow functions, and classes. If the code contains a syntax error, the exact error message from the engine is displayed, letting you jump to the problem and fix it before deployment.

Your JavaScript Stays Private in Your Browser

We process everything locally using JavaScript APIs in your browser. No server requests, no cookies, no account required. The js-beautify library is loaded once from a public CDN and all subsequent processing runs completely offline. You can safely format production scripts, proprietary modules, and internal utilities knowing that nothing is transmitted anywhere.

Related Online JavaScript and Code Tools

If you work with JavaScript regularly, these free tools complement what you can do here:

• JS Formatter -- format, minify, validate, escape, convert JS to JSON, and analyze code structure
• JS Pretty Print -- pretty print JavaScript with configurable indent and bracket matching
• JavaScript Validator -- validate JavaScript syntax and check for errors
• Code Formatter -- format JavaScript, HTML, CSS, JSON, and more in one workspace
• JSON Formatter -- format, minify, validate, and transform JSON data
• CSS Pretty Print -- pretty print, compact, autoprefix, and lint CSS code
• HTML Beautifier -- beautify and format HTML documents