JSON Validator
Validate JSON syntax, detect exact error line and column numbers, and debug malformed JSON.
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About the JSON Validator
A single misplaced comma, unescaped quote, or missing bracket can break an API endpoint. This JSON Validator analyzes your JSON string according to the strict RFC 8259 standard and highlights the exact error location.
How to Use the JSON Validator
- 1Paste your JSON snippet into the editor.
- 2Click "Validate JSON".
- 3If valid, receive confirmation with object structure metrics (keys, arrays, depth).
- 4If invalid, view the precise line number, column index, and descriptive syntax error explanation.
How It Works & Underlying Logic
The tool uses safe JSON syntax inspection to parse tokens and catch SyntaxError exceptions, extracting exact character offsets and line/column coordinates.
Valid: JSON.parse(input) === Success | Invalid: SyntaxError(message, line, col)Practical Calculation Examples
Trailing Comma Error Detection
Identifying invalid trailing comma in an object
Helpful Tips & Best Practices
- •JSON forbids trailing commas in objects and arrays (unlike modern JavaScript).
- •Single quotes ('example') are invalid in JSON; keys and string values must use double quotes ("example").
JSON Validator FAQ
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