JavaScript Formatter - Format and Beautify JS Code Online

Input

Output

What is JavaScript Formatter?

Got messy JavaScript code that's hard to read? Minified code that looks like one giant line? This tool fixes that. It takes your JavaScript and makes it beautiful – proper indentation, line breaks, consistent spacing, everything organized. Whether you're debugging, reviewing code, or just trying to understand what your script actually does, this makes it readable.

According to MDN Web Docs, JavaScript is one of the core technologies powering the web. Our formatter follows modern JavaScript standards and best practices, so your formatted code is clean and maintainable.

Best part? Everything happens instantly in your browser. No server uploads, no data storage – just paste, format, and copy. Your code stays private. Whether you're running code in Node.js or using it in the browser, properly formatted JavaScript is easier to work with.

How to Use the JavaScript Formatter

Follow these steps to format and beautify your JavaScript. Each step uses the actual buttons and panels on this page.

Paste, Upload, or Load Sample

Paste JavaScript into the left Input panel, or click Upload to load a .js file. Click Sample to see example telecomm subscriber code. Example:

const subscriber={subscriberId:"SUB-1001",plan:"Unlimited 5G",dataUsage:45.2,status:"active",carrier:"Verizon"};console.log(subscriber);

Invalid JavaScript will show an error. Fix syntax errors first, then format again.

View Formatted Output

The right Output panel shows the formatted JavaScript instantly. Functions get proper indentation, nested structures are clearly separated.

Copy, Download, or Minify

Click Copy to copy to clipboard, or Download to save as .js. Click Minify for production-ready compact code. Use Clear to start fresh. All processing runs in your browser.

When You'd Actually Use This

Code Review

Reviewing minified or messy code? Format it first to see the structure clearly. Makes it easier to spot bugs, understand logic, or provide feedback to teammates.

Debugging

Trying to debug minified production code? Format it first to make it readable. Much easier to set breakpoints and understand what's happening when the code is properly formatted.

Learning JavaScript

New to JavaScript? Formatting helps you understand the syntax. See how functions nest, how objects work, and how code structures are organized. Much easier than reading minified code.

Legacy Code Maintenance

Working with old, unformatted code? Format it to make it maintainable. Proper indentation and spacing make it way easier to understand and modify.

Common Questions

Is my code stored?

No. All formatting happens in your browser using JavaScript. Your code never leaves your computer.

What JavaScript versions are supported?

We support all modern JavaScript syntax – ES5, ES6+, async/await, arrow functions, classes, modules, you name it. If it's valid JavaScript, we can format it. Check out the ECMAScript for more details.

Can I format invalid JavaScript?

We'll try to format it, but if there are syntax errors, the output might not be perfect. Fix syntax errors first for best results.

What indentation does it use?

We use consistent spacing for indentation, making nested structures easy to read. The exact style follows common JavaScript formatting conventions.

How big can my file be?

Since processing happens in your browser, performance depends on your device. Small files format instantly. Very large files (several MB) might take a few seconds, but they'll still work.

Can I customize the formatting?

Currently, we use standard formatting conventions. If you need specific formatting options, consider using command-line tools like Prettier for advanced customization.

Other JavaScript Tools You Might Need

Formatting is just one JavaScript task. Here are other tools that work well together: