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Free Online JSON Validator

Check JSON syntax and report parsing errors.

Your input stays on this device. Processing is bounded; regex runs in a worker with a two-second timeout.

Result



How to use JSON Validator
Check JSON syntax and report parsing errors. Syntax validation does not apply a JSON Schema or verify the data is appropriate for an API. JavaScript numeric precision limits apply.
  1. Set Input.
  2. Run the tool, review the result and its stated limitations, then copy or download if needed.
Example & practical use
Check JSON syntax and report parsing errors. The example below demonstrates Input.
Example input:
{
  "text": "{\"a\":1}"
}
Expected result (relevant fields):
{
  "valid": true
}
Features & result limitations
Syntax validation does not apply a JSON Schema or verify the data is appropriate for an API. JavaScript numeric precision limits apply.
Frequently asked questions
What inputs does JSON Validator accept?
Input
How should I interpret the JSON Validator result?
Syntax validation does not apply a JSON Schema or verify the data is appropriate for an API. JavaScript numeric precision limits apply.
Where does JSON Validator process my data?
Inputs are processed locally in your browser. Submitted text is not sent to external services. A successful-run event increments an aggregate tool counter without your input.
Learn more