JSON Validator
Validate, format and minify
JSON Validator: Verify and Format JSON Structures
JSON (JavaScript Object Notation) is the standard for data exchange between APIs, config files, and databases. A single misplaced comma can break your entire application.
Our validator not only detects syntax errors — it shows you the exact line and column of the problem, formats the JSON with automatic indentation, and lets you minify it to save bandwidth.
Compatible with JSON standards (RFC 8259) and shows friendly error messages. Ideal for debugging APIs, validating config files, or inspecting AJAX responses.
How does it work?
- 1Paste the JSON
Copy the text or content of the file you want to validate.
- 2Review the result
If valid, you'll see it formatted with indentation. If not, the error will be marked in red with line/column info.
- 3Format or minify
Choose formatted output (readable) or minified (compact) according to your use case.
Frequently Asked Questions
Common mistakes: extra commas at the end of arrays/objects, unescaped double quotes inside strings, unquoted keys, comments (JSON doesn't allow them), or hidden non-printable characters.
Standard JSON is strict — no comments, keys must be quoted, no trailing commas. JSONC (used by VSCode) allows comments. JSON5 is more permissive and human-friendly. Our validator handles strict JSON.
This tool validates JSON syntax. For structure validation against a schema (JSON Schema), you need a specific validator. We plan to add it in future versions.