JSON Validator
Check JSON syntax and identify errors instantly
Input JSON
Output
What is JSON Validator?
JSON validation confirms your data follows the JSON specification exactly. A single misplaced comma, missing quote, or trailing comma can break parsers. Our validator pinpoints the exact location of syntax errors with clear, actionable messages.
Unlike lenient JavaScript parsers that accept invalid JSON, strict validation catches problems before they reach production. This is especially important when JSON will be consumed by systems you don't control.
Why Use This Tool?
Debugging JSON syntax errors in code is frustrating. Error messages like "Unexpected token" rarely indicate the actual problem location. Our validator provides precise line and column numbers along with explanations of what's wrong.
Validation is also essential before data exchange. APIs should validate incoming JSON before processing. Configuration files should validate before deployment. Catching errors early prevents cascading failures.
How It Works
Validation checks JSON against RFC 8259:
• Proper use of quotes (double quotes only, not single) • Correct comma placement (no trailing commas) • Valid escape sequences in strings • Number format compliance • Proper nesting and bracket matching • UTF-8 encoding correctness
Any deviation is reported with specific location and explanation.
Common Use Cases
- Debugging malformed API responses
- Validating configuration files
- Checking JSON before database storage
- Verifying exported data integrity
Pro Tip
Common errors: trailing commas (invalid in JSON), single quotes (must be double), and unquoted keys (must be quoted strings).
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