JSON Formatter & Validator

The Ultimate JSON Formatter & Validator

Welcome to the most complete JSON tool on the web. Whether you are a backend developer debugging an API, a data analyst converting formats, or a student learning data structures, this tool is designed for speed, accuracy, and privacy.

Why Format JSON?

JSON (JavaScript Object Notation) is designed to be lightweight and easy for machines to parse. However, minified JSON—often used to save bandwidth—is virtually unreadable to humans. Formatting (or "beautifying") JSON adds indentation and line breaks, making the hierarchical structure clear immediately.

Key Features

• Strict Validation: Identifies syntax errors like trailing commas or unquoted keys with line-number precision.
• Interactive Tree View: Explore deeply nested objects by collapsing nodes. Click any key to copy its exact path (e.g., data.users[0].id).
• Privacy First: All processing happens in your browser's JavaScript engine. No data is sent to our servers.
• Conversion Tools: Instantly transform JSON arrays into CSV for Excel, or YAML for configuration files.
• Visual Diff: Compare two JSON versions to spot changes in API responses or config files.

JSON Syntax Guide (RFC 8259)

Valid JSON must adhere to strict rules:

• Data is in name/value pairs.
• Data is separated by commas.
• Curly braces {} hold objects.
• Square brackets [] hold arrays.
• Keys must be strings enclosed in double quotes "key".
• Strings must use double quotes (not single quotes).

Common Errors We Fix

Developers often encounter these common issues which our validator highlights:

// Invalid (Trailing comma)
{ "id": 1, "name": "Gemini", }

// Invalid (Single quotes)
{ 'id': 1 }

// Valid
{ "id": 1, "name": "Gemini" }

About The Project

This tool is maintained by the open-source community to provide a strong, ad-supported free utility. We adhere to the highest standards of web performance.

Internal Tools: Regex Tester | Base64 Encoder | Hash Generator | Diff Checker