JSON Formatter & Validator
Format, beautify and validate JSON instantly in your browser. Paste minified JSON and get clean, indented output with error line numbers.
IN: JSON text · OUT: Formatted JSON · RUNS: 100% in your browser
indent
// formatted output appears here
Frequently asked questions
Is my JSON data uploaded anywhere?+
No. Formatting and validation run entirely in your browser using JavaScript. Your JSON never leaves your device.
Can this tool fix invalid JSON?+
It highlights the exact line and character where parsing fails so you can fix syntax errors like trailing commas or missing quotes, but it does not auto-repair JSON.
What indentation does the formatter use?+
You can choose between 2 spaces, 4 spaces, or tab indentation using the control above the output panel.
Is there a file size limit?+
The tool can comfortably handle JSON documents of several megabytes since processing happens locally, without a server round trip.