JSON Validator
Validate JSON syntax and get plain-English hints for errors. Fast, free, and fully client-side.
Input source
Result / Output
Paste JSON in the input area to validate...
How the JSON Validator Works
Validates JSON syntax against RFC 8259 specifications, pinpointing missing commas, unquoted keys, trailing commas, and unclosed brackets.
Usage Example
Identifies exact error lines in large JSON payloads with actionable error descriptions.
Frequently Asked Questions
Are trailing commas allowed in standard JSON?
No, standard JSON strictly disallows trailing commas after the last array item or object property.
Browse more
See all JSON tools.