What is a JSON Formatter?

A JSON Formatter (also called a JSON Beautifier or Pretty Printer) takes unformatted or minified JSON text and adds indentation, line breaks, and whitespace to make it human-readable.

Is my JSON data safe on PrettyJSON.in?

Yes, 100%. All JSON parsing, formatting, and validation happens locally inside your web browser. Zero data is ever uploaded or sent to any external server.

What is the difference between Pretty Print and JSON Minify?

Pretty Printing adds whitespace and indentation for readability during development. JSON Minifying removes all unnecessary whitespace to compress file size for production APIs.

How do I format JSON in JavaScript and Python?

In JavaScript, use JSON.stringify(data, null, 2). In Python, use json.dumps(data, indent=2).

Raw JSON Input

Waiting for JSON content

Start typing on the left or load one of the sample payloads to inspect it instantly.

RFC 8259 Compliant & 100% Client-Side

Online JSON Syntax Validator & Linter

Validate JSON syntax in real-time. Detect exact line numbers, column markers, missing quotes, and invalid syntax according to RFC 8259 specifications.

Explore Specialized JSON Tools

JSON Formatter

Format & beautify raw JSON with 2-space or 4-space indentation.

JSON Minifier

Compress JSON payloads onto 1 line & calculate bandwidth savings.

JSON Validator

Real-time RFC 8259 syntax checker with exact line & column error pinpointing.

JSON Tree Viewer

Inspect nested API responses with interactive node expansion & key search.

JSON Repair

Auto-Fix

Auto-fix single quotes, trailing commas, unquoted keys, and JS comments.

100% Private & Offline Ready

No backend requests. Your sensitive payloads remain strictly on your local device.

Zero Network Latency

Instantaneous formatting, minification, repair, and tree view rendering with zero server roundtrips.

Exact Error Line Pinpointing

Detect unescaped quotes, trailing commas, and structural syntax errors with exact line & column markers.

PrettyJSON vs. Traditional Online JSON Editors

See how PrettyJSON outperforms older web formatters in privacy, performance, and developer utility.

Feature	PrettyJSON.in	Traditional Editors
Privacy & Security	100% In-Browser (0 Server Logs)	Often Uploads to Server
Speed & Performance	Instant Local JS / Web Processing	Network Request Latency
View Modes	Interactive Text & Tree View	Text Only
JSON Auto-Repair	Built-in Auto-Fix Engine	Manual Editing Only
Error Handling	Exact Line & Column Highlighting	Generic Error Messages

Programmatic JSON Pretty Printing Examples

How to format and beautify JSON programmatically across languages and command line tools.

JavaScript (Browser / Node.js)

const data = { name: "PrettyJSON", rating: 5, active: true };
// Pretty print with 2-space indentation
const formatted = JSON.stringify(data, null, 2);
console.log(formatted);

Python

import json

data = {"name": "PrettyJSON", "rating": 5, "active": True}
# Pretty print with 2-space indentation
formatted = json.dumps(data, indent=2)
print(formatted)

cURL & jq (Command Line)

# Fetch API response and beautify instantly with jq
curl -s https://api.example.com/data | jq '.'

# Compact / Minify JSON output
curl -s https://api.example.com/data | jq -c '.'

Frequently Asked Questions

Common questions and expert answers regarding this tool.

What makes JSON syntax valid or invalid?

Valid JSON must follow RFC 8259 rules: keys must be double-quoted strings, trailing commas are disallowed, values must be valid types (string, number, object, array, boolean, null), and single quotes or unescaped control characters are invalid.

How does PrettyJSON locate syntax errors?

PrettyJSON uses a real-time RFC 8259 parser that pinpoints the exact line number and column marker of syntax errors, highlighting missing braces, trailing commas, or unquoted keys.

What is the difference between JSON and a JavaScript Object?

JavaScript objects permit single quotes, unquoted keys, functions, and trailing commas. Standard JSON is a strict data interchange format requiring double quotes around all keys and strings.