JSON Validator
Check JSON syntax and see exactly where it breaks.
Input
This tool runs entirely in your browser. The data you paste or load is never uploaded.
Result
Enter your input, then run the tool.
About this tool
Validates a JSON document against RFC 8259 and reports the first syntax error with its line and column. A summary shows keys, arrays, nesting depth and the types in use so you can spot structural mistakes.
How to use it
- Paste the document you want to check.
- Press Validate to parse it with the browser’s strict JSON parser.
- Fix the reported position, then validate again.
Example
Input
{"valid":true,"count":3}
Output
Valid JSON Type: object Keys: 2 Maximum depth: 1
Frequently asked questions
Is a comment allowed in JSON?
No. Standard JSON has no comments; a parser will reject // and /* */ blocks. Remove them or use JSON5 tooling before validating.
Can I validate a file?
Open the file in any text editor, paste its contents here, and validate. Nothing is uploaded anywhere.
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