Paste JSON to validate syntax. Invalid JSON shows an error with details; valid JSON is formatted for easy reading. No upload, no signup. Runs in your browser.
Valid JSON
About JSON Validator
This tool checks whether your text is valid JSON. It uses the browser's native parser and shows a clear error message and position when something is wrong. When valid, it displays a formatted version so you can copy clean, indented JSON.
How to use
- Paste or type JSON into the box.
- Click Validate JSON. Errors appear below if invalid; otherwise you see the formatted result.
Frequently Asked Questions
What does the JSON validator check?
It checks that your text is valid JSON: correct brackets, commas, quotes, and escaping. If invalid, it shows the error message and approximate position.
Is my JSON sent to a server?
No. Validation runs entirely in your browser using JavaScript. Your data never leaves your device.
Can I format minified JSON?
Yes. When your JSON is valid, the tool shows a formatted (pretty-printed) version that you can copy.