@toolsnap/json-beautify

A lightweight, zero-dependency JSON formatting library for Node.js. Beautify, minify, and validate JSON with a clean, predictable API.

Installation

npm install @toolsnap/json-beautify

Why This Library?

Working with JSON in Node.js is routine, but the built-in JSON.stringify only goes so far. You constantly need to: pretty-print API responses for debugging, minify payloads before transmission, and validate user-provided JSON with meaningful error information. This package wraps those three operations into a simple, consistent interface.

For an interactive online tool with syntax highlighting and error indicators, try the JSON Formatter on Risetop — it supports tree view, path copying, and batch formatting.

API

beautify(input, indent = 2)

Pretty-prints JSON with configurable indentation. Accepts either a JSON string or a plain JavaScript object.

const { beautify } = require('@toolsnap/json-beautify');

// From string
beautify('{"name":"Alice","age":30}');
// {
//   "name": "Alice",
//   "age": 30
// }

// From object
beautify({ users: [{ id: 1, role: 'admin' }] }, 4);
// {
//     "users": [
//         {
//             "id": 1,
//             "role": "admin"
//         }
//     ]
// }

Throws if the input string contains invalid JSON.

minify(input)

Removes all unnecessary whitespace from a JSON string or object.

const { minify } = require('@toolsnap/json-beautify');

const original = '{\n  "name": "test",\n  "items": [1, 2, 3]\n}';
minify(original);
// '{"name":"test","items":[1,2,3]}'

console.log('Size saved:', original.length - minify(original).length, 'bytes');

validate(input)

Validates a JSON string and returns detailed diagnostics including error position.

const { validate } = require('@toolsnap/json-beautify');

validate('{"valid": true}');
// { valid: true, error: null, data: { valid: true }, position: null }

validate('{"missing": ');
// { valid: false, error: 'Unexpected end of JSON input', data: null, position: { position: 12 } }

The returned object always has four fields: valid, error, data, and position.

Real-World Examples

Logging API Responses

const { beautify } = require('@toolsnap/json-beautify');

// After fetching from an API
const response = await fetch('https://api.example.com/users');
const data = await response.json();

console.log(beautify(data, 2));

Processing Configuration Files

const { beautify, minify, validate } = require('@toolsnap/json-beautify');
const fs = require('fs');

// Read, validate, reformat
const raw = fs.readFileSync('config.json', 'utf8');
const result = validate(raw);

if (!result.valid) {
  console.error(`Invalid JSON at position ${JSON.stringify(result.position)}: ${result.error}`);
  process.exit(1);
}

fs.writeFileSync('config.min.json', minify(result.data));
fs.writeFileSync('config.pretty.json', beautify(result.data, 4));

HTTP Response Compression Helper

const { minify, validate } = require('@toolsnap/json-beautify');

function jsonMiddleware(req, res, next) {
  const originalSend = res.json.bind(res);
  res.json = (data) => {
    const body = JSON.stringify(data);
    if (validate(body).valid) {
      res.setHeader('Content-Type', 'application/json');
      res.send(minify(body));
    } else {
      res.status(500).send('Invalid JSON');
    }
  };
  next();
}

Browser Usage

This is a CommonJS module. Bundle with your preferred tool (webpack, esbuild, Rollup) for browser use.

Related Tools

• JSON Formatter — Free online JSON beautifier with syntax highlighting and error detection
• Developer Tools Collection — More free developer utilities

License

MIT