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Validate JSON data for syntax errors and structural issues with detailed error reporting and suggestions.
A JSON validator checks that a block of JSON is syntactically correct and, when something is wrong, tells you exactly where. Paste an API response, a config file, or any JSON text and the tool confirms whether it parses cleanly — flagging issues like a trailing comma, a missing brace, or an unquoted key with the precise line and column of the error.
Validation happens as you type, and everything runs locally in your browser. The JSON you paste is never uploaded, logged, or stored, so you can check sensitive payloads without them leaving the tab. Beyond a simple pass or fail, the tool can format the JSON for readability or minify it, and it produces a structural analysis showing the document's size, nesting depth, and counts of objects, arrays, keys, and value types.
This makes it well suited to debugging API responses, verifying configuration files before deployment, and understanding the shape of an unfamiliar data structure. Because the validator reports the exact location of the first error, fixing malformed JSON is fast even in large documents.
No. Validation, formatting, and analysis all run locally in your browser, so the JSON you paste is never sent to a server.
When JSON fails to parse, the tool reports the error message along with the exact line and column of the problem, so you can locate and fix it quickly.
It reports the document's size in bytes, its maximum nesting depth, and counts of objects, arrays, keys, primitive values, and each data type present.
The most frequent are trailing commas, single quotes instead of double quotes, unquoted keys, and missing or mismatched brackets and braces.
Yes. Once your JSON is valid you can switch to Format mode for readable indentation or Minify mode to strip whitespace into a compact single line.