JSON Validator
Validate JSON syntax and get precise line and column error information.
JSON Input
What is the JSON Validator?
The JSON Validator checks whether a document is syntactically valid JSON and pinpoints exactly where parsing fails, with line and column information. It's the quickest way to answer "why won't this parse?" when an API request or config file is rejected.
Validation uses the browser's native JSON parser — the same one JavaScript runtimes use — so the result reflects real-world strict JSON behavior, not a lenient approximation. Valid documents can be pretty-printed with one click.
How to use the JSON Validator
- Paste your JSON into the editor.
- Validation runs as you type — a large status banner shows Valid or Invalid.
- If invalid, read the error message with line and column details and fix the input.
- For valid JSON, click Pretty Print to view a formatted copy and copy the result.
Examples
Invalid: trailing comma
{
"name": "Ada",
}Strict JSON forbids trailing commas — the validator points at line 3.
Invalid: single quotes
{ 'name': 'Ada' }JSON strings and keys must use double quotes.
Frequently asked questions
What's the difference between the validator and the formatter?
Both parse your JSON the same way. The validator focuses on a clear valid/invalid verdict with detailed error location, while the formatter focuses on producing beautified or minified output.
Does it validate against a JSON Schema?
No — this tool checks syntax only. Schema validation (checking that data matches a defined structure) is a separate concern we may add in the future.
Why does JSON5 or JSONC fail validation?
Comments, trailing commas, and unquoted keys are extensions from JSON5/JSONC and are not valid in strict JSON, which is what APIs and JSON.parse expect.