What counts as valid JSON?

Anything JavaScript's built-in JSON.parse accepts — the same strict JSON syntax used by APIs and config files. Trailing commas, comments, and unquoted keys are not valid JSON and will be flagged.

Is my JSON uploaded anywhere?

No — validation runs entirely in your browser.

JSON Validator

Developer Tools

Check whether a JSON document is valid, with the exact error location when it isn't.

What you can do with this tool

Check an API response for a syntax error before debugging further
Confirm a config file is valid JSON before deploying it

Frequently asked questions

What counts as valid JSON?: Anything JavaScript's built-in JSON.parse accepts — the same strict JSON syntax used by APIs and config files. Trailing commas, comments, and unquoted keys are not valid JSON and will be flagged.
Is my JSON uploaded anywhere?: No — validation runs entirely in your browser.

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