JSON

JSON Validator

Check JSON syntax instantly, without sending it anywhere.

JSON input

What is JSON Validator?

Validate JSON documents in your browser before using them in an API, config file, or application. The built-in JSON parser checks the same strict JSON syntax your JavaScript runtime expects.

How to use JSON Validator

  1. Paste or type your input into the editor.
  2. Use the tool action to process your data in the browser.
  3. Review the output, then copy or download it if needed.

Key features

Frequently asked questions

Does this validator upload my JSON?

No. Validation uses your browser's JSON parser and the input never leaves your device.

Why is valid JavaScript not always valid JSON?

JSON is stricter: it requires double quotes around property names and strings, and it does not permit comments, trailing commas, or undefined values.