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JSON Validator

Paste JSON to check whether it is valid. Errors point to the exact line and column.

JSON input

Paste text or drop a file here (up to 50 MB).

JSON result

Free to use. Your input stays in this browser.

How to use it

  1. Paste JSON or drop a file. The check runs as you type.
  2. If there is an error, read the cause and select Show in input to jump to that spot.
  3. Once it is fixed, the result reads Valid JSON and a formatted copy is ready to use.

The validator follows the JSON standard (RFC 8259). Comments, single quotes, trailing commas, unquoted keys, NaN, and leading zeros are reported because strict parsers reject them.

The standard allows duplicate keys, but parsers handle them differently. They stay in the output so you can spot them.

Example

JSON input
{
  "name": "Convertools",
  "tags": ["json", "xml"],
  "active": true,
}
JSON result
Remove this trailing comma. JSON does not allow a comma before } or ].
Line 4, column 17