JavaScript Beautifier

Format compact JavaScript into readable source code in your browser.

Input
Output
0 characters 0 lines

What does JavaScript Beautifier do?

JavaScript Beautifier formats JavaScript source for readability without changing intended behavior.

  • Primary use: JavaScript Beautifier formats JavaScript source for readability without changing intended behavior.
  • Key technical fact: JavaScript syntax is standardized by ECMAScript and includes statements, expressions, modules, and functions.
  • Practical check: Run the formatted or minified output through your parser, tests, or runtime when exact syntax behavior matters.
Topic Direct answer Source
Direct answer JavaScript Beautifier formats JavaScript source for readability without changing intended behavior. ECMAScript specification
Key fact JavaScript syntax is standardized by ECMAScript and includes statements, expressions, modules, and functions. ECMAScript specification
Processing model Runs locally in the browser; no production Node server receives the input. Browser JavaScript

Make JavaScript readable without rewriting logic

JavaScript Beautifier expands compact or messy JavaScript into readable blocks, statements, and expressions. It helps when inspecting minified snippets, debugging copied code, reviewing generated scripts, or preparing examples.

Beautifying changes whitespace and line breaks; it does not deobfuscate renamed variables, restore original comments, infer TypeScript types, or guarantee that already-broken code becomes valid.

How to use

  1. Paste your JavaScript code into the input editor.
  2. Click Beautify JavaScript to reflow statements and blocks.
  3. Review the output for preserved strings, comments, and runtime-sensitive syntax.
  4. Use Copy for the clipboard, Download for a file, or Clear to reset.

What is JavaScript Beautifier?

JavaScript Beautifier is a browser-based utility for reformatting JavaScript so control flow, functions, objects, arrays, and chained calls are easier to read.

Formatting is intended to preserve behavior, but JavaScript has edge cases around automatic semicolon insertion, directives, regular expressions, and template literals. Test important code after reformatting.

Input notes

Paste plain JavaScript, not HTML <script> tags unless the tool is meant to process them as text. For JSX, TypeScript, or framework templates, confirm the output with your normal parser.

Example

A compact function is reflowed into a more readable block:

--- Minified Input ---
function hello(name){console.log("Hello, "+name+"!");}

--- Beautified Output ---
function hello(name) {
  console.log("Hello, " + name + "!");
}

MCP integration

MCP (Model Context Protocol) lets AI agents and apps discover and run Coding.Tools utilities for repeatable conversions, formatting, hashing, and generation workflows.

MCP tool name: javascript-beautifier

MCP endpoint: https://coding.tools/mcp

Call tools/list first. Each tool entry includes inputSchema, outputSchema, and examples so an AI agent or client can build valid arguments without guessing.

For tools/call, read result.content[0].text for the display value and result.structuredContent for machine parsing. Tool-level failures return isError: true; protocol failures return a JSON-RPC error.

Example tools/call request:

curl -s https://coding.tools/mcp \
  -H "Content-Type: application/json" \
  -H "Accept: application/json" \
  -H "MCP-Protocol-Version: 2025-06-18" \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"javascript-beautifier","arguments":{"input":"function total(items){return items.reduce((sum,item)=>sum+item.price,0);}"}}}'

Most text and data tools accept an input string plus optional options. Browser-only image tools are listed for discovery and return a web UI link when they need browser image APIs.