What the JSON Formatter & Validator Does
JavaScript Object Notation (JSON) is the dominant standard data interchange format for RESTful APIs, configuration files, and modern web services. When viewing minified API responses or debugging database exports, raw JSON arrives as an unreadable single line of text with missing indents and escaped quotes.
This client-side tool parses your JSON structure and applies customizable hierarchical indentation (2 spaces, 4 spaces, or tabs). Furthermore, if your document contains malformed syntax—such as unquoted keys, trailing commas, or single-quote wrappers—the validator detects the exact line number and character column to accelerate debugging.
How to Format and Inspect JSON
- Paste Raw Payload: Paste your JSON string into the main code editor window.
- Prettify: Click "Prettify JSON" to format objects and arrays with clear indentation and line breaks.
- Minify: Click "Minify JSON" to strip all whitespace characters, creating a compact payload ideal for high-throughput network transport.
- Troubleshoot Errors: If syntax errors are found, the alert box displays the exact parser message alongside the offending line number.
- Export: Click "Copy" to save the result to your clipboard, or "Download .json" to export a clean file to disk.
Worked Example
Problematic Input: {"name": "Mubarak", "active": true,} (Notice trailing comma)
Parser Diagnostic: Invalid JSON at line 1, column 34: Unexpected token '}' in JSON at position 33
Fix Applied: Stripped the extra comma → Validated successfully!
Strict JSON Specifications Reference
| Rule | Valid Syntax Example | Invalid Common Error |
|---|---|---|
| Key Quotation | {"userId": 101} (Double quotes) |
{userId: 101} or {'userId': 101} |
| Trailing Commas | [1, 2, 3] (No final comma) |
[1, 2, 3,] |
| String Values | "status": "success" |
'status': 'success' (Single quotes forbidden) |
| Booleans & Null | true, false, null (Lowercase) |
True, False, NULL |