TOON Beautifier

How to Format and Validate JSON Online

1. Paste or Upload: Insert your raw JSON string or drag-and-drop a .json file into the editor.
2. Select Indentation: Choose 2 spaces (standard web), 4 spaces (readable), or Minify (single-line compact).
3. Inspect and Fix: The real-time validator highlights syntax errors, unescaped characters, or missing quotes immediately.
4. Copy or Export: Copy the formatted output with one click or download the clean file.

Common JSON Syntax Errors and Fixes

• Trailing Commas: Arrays and objects cannot end with a comma before the closing bracket (e.g., {"a": 1,} is invalid). Remove any lingering trailing commas.
• Single Quotes: RFC 8259 requires double quotes around keys and string values (e.g., 'key' must be "key"). Replace single quotes with double quotes.
• Unquoted Keys: Object keys must always be enclosed in quotation marks. Unquoted JavaScript-style keys (e.g., {name: "value"}) will fail validation.
• Unescaped Characters: Special characters like newlines (\n), tabs (\t), or backslashes within string values must be properly escaped.

Secure Client-Side JSON & TOON Formatting

Data privacy is critical for developers. This formatter processes all inputs locally in your browser using high-speed Web Workers. No payload strings, configurations, API keys, or JSON data are ever logged or uploaded to external servers, providing full compliance with enterprise confidentiality requirements.