JSON Validator

Validate JSON data and find errors with line numbers instantly.

Error detectionLine numbersNo signup
Text stays on your device

Documentation

What is JSON validation?

JSON validation checks whether your data follows the correct JSON syntax rules. It catches errors before they cause problems in your application.

Why validate JSON?

Invalid JSON can crash apps, break API calls, and cause config errors. Validating first saves debugging time.

How to use
  1. 1) Paste your JSON data into the input box.
  2. 2) Click Validate to check for errors.
  3. 3) Review the result — valid or error with details.

FAQs

What is a JSON validator?

A JSON validator checks whether your JSON data is syntactically correct and reports errors with exact line numbers.

What errors can JSON have?

Common errors include missing commas, unclosed brackets, trailing commas, unquoted keys, and incorrect string values.

Does this tool store my JSON?

No. All validation happens locally in your browser. Your data is never uploaded or stored.

Is it free?

Yes. The JSON validator is completely free with no signup or limits.

What is the difference between validation and formatting?

Validation checks if JSON is correct. Formatting makes valid JSON readable by adding indentation. This tool does both.

Privacy: All processing runs in your browser. Nothing is stored.