Check JSON Syntax Instantly
JSON is the exchange format that powers modern AI workflows — API responses, configuration files, function-calling schemas and RAG datasets. A single stray comma or unclosed brace can break an entire pipeline. A validator catches those problems before they reach production.
Pinpoint Errors by Line and Column
Instead of scanning a large document by hand, paste your JSON and get the exact error message, line and column of the first syntax problem, so you can jump straight to the fix.
Understand Your Data Structure
When the JSON is valid, the tool reports the top-level type, the number of keys or items, the maximum nesting depth and the character and byte size — a quick structural summary for any payload you are preparing or debugging.
Readable Pretty-Printed Preview
Valid input is re-rendered with two-space indentation and syntax highlighting, making keys, strings, numbers, booleans and null values easy to distinguish at a glance.
Private and Offline-Ready
Everything runs client-side. Your JSON is processed by your browser's own JavaScript engine and never uploaded, making the tool safe for sensitive data.