Why JSON Validation Matters
A single misplaced comma or missing quotation mark can break an entire application. JSON validation against RFC 8259 catches these errors before they reach production.
What Our JSON Validator Checks
- Unexpected tokens: Single-quoted strings, unquoted keys, JavaScript comments.
- Trailing commas: Commas after the last key in objects or last item in arrays.
- Unclosed brackets: Missing
}or]at the end. - Invalid escape sequences: Malformed Unicode or control characters.
- Number format violations: Leading zeros, NaN, Infinity values.
How to Validate JSON Online
- Paste your JSON text into the validator input.
- Validation runs automatically as you type.
- Errors are highlighted with the exact line and character position.
- Green checkmark confirms valid RFC 8259 compliant JSON.
json
// Invalid JSON (fails validation)
{
'name': 'Alice', // Single quotes not allowed
"roles": ["admin",], // Trailing comma
"active": True // Case-sensitive: must be true
}
// Valid JSON (passes validation)
{
"name": "Alice",
"roles": ["admin"],
"active": true
}