Is my data sent to a server?

No. All processing happens in your browser. Your JSON never leaves your device.

What does this validator check?

This tool checks for strict JSON syntax compliance per RFC 8259. It will flag issues like trailing commas, unquoted keys, and incorrect value types.

Does it support JSON5 or comments in JSON?

No. This validator checks standard JSON only. JSON5 and JSONC (with comments) are not valid JSON and will be flagged as errors.

JSON Validator

Validate JSON online instantly. Check JSON syntax, identify errors with location info, and view root type, key count, and nesting depth.

JSON Input

What does this tool do?

The JSON Validator checks whether your JSON input is syntactically valid according to the JSON specification (RFC 8259). If valid, it shows useful statistics. If invalid, it pinpoints the error location.

How to use this tool

Paste your JSON into the text area
Click Validate
If valid: see root type, key/item count, and maximum nesting depth
If invalid: see the exact error message from the JSON parser

What the stats mean

Root Type — whether the top-level value is Object, Array, String, Number, Boolean, or Null
Top Keys / Items — number of properties (for objects) or elements (for arrays) at the root level
Max Depth — the maximum nesting depth of the JSON structure

Common use cases

Verifying API response payloads are well-formed
Checking configuration files before deployment
Debugging JSON that causes parse errors in applications
Quick sanity check for JSON generated by scripts
Validating webhook payloads or request bodies

Common JSON errors

Trailing commas after the last property or element
Single-quoted strings (JSON requires double quotes)
Unescaped control characters in strings
Missing or extra closing brackets/braces
Comments (not allowed in standard JSON)

Privacy

All processing happens in your browser. Nothing is transmitted.