JSON Validator

Validate JSON syntax and find parser errors with line numbers.

A JSON validator is most useful when a payload fails to parse and the source of the problem is not obvious. DataConvertor validates JSON in the browser, reports line and column details when the parser provides them, and shows a highlighted code frame so you can fix syntax faster.

What problem it solves

Broken JSON often comes from missing commas, mismatched braces, stray quotes, or unescaped characters copied from logs, forms, or API docs. When you only see “Unexpected token” or “Unexpected end of JSON input,” a validator with line-level context saves time.

Example

Invalid JSON
{
  "name": "Ada",
  "active": true
  "role": "admin"
}

Error
Missing comma before "role" on line 4.

What DataConvertor shows

• Parser errors mapped to line and column positions when available.
• A highlighted code frame around the failing line.
• Pretty-printed JSON output when the payload is valid.
• A preview table for parsed arrays or objects when the JSON is usable.