How do I validate malformed JSON?

Paste your JSON string above; any syntax or trailing comma error is highlighted with an exact error message.

Is my API payload sent to any server?

No, all formatting executes strictly inside your browser memory.

100% Client-Side • Zero Data Leaves Browser

Prettify minified JSON with 2-space indentation and detect syntax errors immediately in your browser.

Active Converter / Utility

Input Data Upload File

Output Result