JSON Validator
Validate JSON syntax instantly with detailed error messages showing the exact line and position of errors. Format valid JSON with indentation.
Examples
Valid JSON object
In:{"name": "Alice", "age": 30, "languages": ["JavaScript", ...
Invalid JSON (missing comma)
In:{"name": "Alice" "age": 30}
Nested valid JSON
In:{"server": {"host": "localhost", "port": 8080}, "debug": ...
How to Use JSON Validator
- Paste or type your JSON into the input area.
- Click "Validate" or use an example to test.
- If the JSON is valid, the formatted output appears on the right.
- If invalid, an error message shows the line and position of the issue.
- Click "Copy" to copy the formatted result.
What is JSON?
JSON (JavaScript Object Notation) is a lightweight data-interchange format that is easy for humans to read and write, and easy for machines to parse and generate. It is widely used in web APIs, configuration files, and data storage. Valid JSON requires strict syntax: strings must be double-quoted, no trailing commas are allowed, and all brackets and braces must be properly matched.