What is JSON Validation?
JSON validation checks whether a piece of text conforms to the JSON specification (RFC 8259). Valid JSON must have proper syntax including correctly matched brackets, properly quoted strings, and correct use of commas and colons. Our validator instantly tells you if your JSON is valid and shows exactly where any errors occur.
100% Private: All validation happens in your browser. Your JSON data never leaves your device.
Common JSON Errors & How to Fix Them
Trailing Comma
JSON doesn't allow a comma after the last item.
{"name": "John", "age": 30,}
{"name": "John", "age": 30}
Single Quotes
JSON requires double quotes, not single quotes.
{'name': 'John'}
{"name": "John"}
Unquoted Keys
All property names must be in double quotes.
{name: "John"}
{"name": "John"}
Comments
Standard JSON doesn't support comments.
{"name": "John" // comment}
{"name": "John"}
Features
Instant Validation
Get immediate feedback on whether your JSON is valid or invalid.
Error Location
See the exact line and column number where the error occurs.
Clear Messages
Understand what went wrong with human-readable error descriptions.
Works Offline
Validate sensitive data without sending it over the network.
Frequently Asked Questions
JSON validation is the process of checking whether a piece of text conforms to the JSON specification (RFC 8259). A valid JSON must have proper syntax including correctly matched brackets, properly quoted strings, and correct use of commas and colons.
Common JSON validation errors include: trailing commas after the last item, single quotes instead of double quotes, unquoted property names, missing commas between items, unclosed brackets or braces, and comments (which aren't allowed in standard JSON).
Our validator shows the exact line and column where the error occurs. Common fixes include: replacing single quotes with double quotes, removing trailing commas, adding missing commas between items, ensuring all brackets are closed, and removing any comments.